研究者詳細 - 石原　大輔

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Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling 査読有り

Ishihara D., Nozaki S., Niho T., Takayama N.

CMES - Computer Modeling in Engineering and Sciences 140 ( 2 ) 1371 - 1386 2024年01月

担当区分：筆頭著者,　最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters. Existing strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic formulations. Each formulation has its advantages and disadvantages, and the choice depends on the characteristics of each coupled problem. This study proposes a new option: a coupled analysis strategy that combines the best features of the existing formulations, namely, the hybrid partitioned-monolithic method. The analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly coupled using a partitioned iterative hierarchical algorithm. In a typical benchmark problem of a piezoelectric energy harvester, this research compares the results from the proposed method to those from the conventional strongly coupled partitioned iterative method, discussing the accuracy, stability, and computational cost. The proposed hybrid concept is effective for coupled multi-physics problems, including various coupling conditions.

DOI： 10.32604/cmes.2024.049694

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Numerical analysis of insect flight maneuverability using feedback control model 査読有り国際誌

Sugikawa Kaede, Onishi Minato, Ishihara Daisuke

日本シミュレーション学会英文誌 ( 一般社団法人日本シミュレーション学会 ) 11 ( 1 ) 201 - 206 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, we propose a new feedback control model for insect flight maneuverability, and conduct the numerical analysis using the proposed model. In the proposed model, the feedback control based on the observation for actual insects is introduced to the partitioned analysis model for the wing-body interaction, where the flapping wings and the surrounding air flow coupling is monolithically formulated using a finite element method such that the wing’s characteristic motions are simulated stably, while the one-way coupling from the wings to the body is used assuming a perturbation from the quasi-steady flight state. The roll control, on which we focus here, in our numerical result shows the good agreement with the body’s attitude control of an actual insect observed in the previous experiment. In our future work, we will elucidate a maneuverability mechanism of controlling body’s attitudes in insect flapping flight using the proposed model.

DOI： 10.15748/jasse.11.201

その他リンク： https://www.jstage.jst.go.jp/article/jasse/11/1/11_201/_pdf

Fabricable polymer micromachined insect mimetic wing for pico air vehicles 査読有り国際誌

Shankar V., Shirakawa N., Ishihara D.

2024 IEEE 19th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2024 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents a novel fabricable design and demonstration of a polymer micromachined wing for flapping wing pico air vehicles, which is capable of producing camber deformations similar to those of real insects. The proposed wing is a 2.5-dimensional structure comprised of the leading edge, center, and root veins, and the wing membrane such that it can be fabricated using polymer micromachining. The design window that refers to the area of satisfactory design solutions is iteratively searched using a nonlinear finite element structural analysis. In the design problem, the mean camber is the design characteristic, the thickness of each vein is the design parameter, and the design constraint is the fabricability. A final design solution with sufficient camber is selected from the design window, and the fabricability is demonstrated using polymer micromachining.

DOI： 10.1109/NEMS60219.2024.10639876

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Algorithm Selection Method Based on Coupling Strength for Partitioned Analysis of Structure-Piezoelectric-Circuit Coupling 査読有り国際誌

Ishihara D., Takayama N.

CMES - Computer Modeling in Engineering and Sciences 138 ( 2 ) 1237 - 1258 2024年01月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, we propose an algorithm selection method based on coupling strength for the partitioned analysis of structure-piezoelectric-circuit coupling, which includes two types of coupling or inverse and direct piezoelectric coupling and direct piezoelectric and circuit coupling. In the proposed method, implicit and explicit formulations are used for strong and weak coupling, respectively. Three feasible partitioned algorithms are generated, namely (1) a strongly coupled algorithm that uses a fully implicit formulation for both types of coupling, (2) a weakly coupled algorithm that uses a fully explicit formulation for both types of coupling, and (3) a partially strongly coupled and partially weakly coupled algorithm that uses an implicit formulation and an explicit formulation for the two types of coupling, respectively. Numerical examples using a piezoelectric energy harvester, which is a typical structure-piezoelectric-circuit coupling problem, demonstrate that the proposed method selects the most cost-effective algorithm.

DOI： 10.32604/cmes.2023.030211

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ポリマーマイクロマシニングによる昆虫規範型マイクロ弾性翼の作製可能解

白川和, ヴィナイシャンカー, 木村元宣, 石原大輔

[No. 23-17] 日本機械学会第34回バイオフロンティア講演会〔2023.12.16-17，山口大学〕予稿集 1F10 2023年12月

Vein–Membrane Interaction in Cambering of Flapping Insect Wings 査読有り国際誌

Ishihara D., Onishi M., Sugikawa K.

Biomimetics ( MDPI AG ) 8 ( 8 ) 571 - 571 2023年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

It is still unclear how elastic deformation of flapping insect wings caused by the aerodynamic pressure results in their significant cambering. In this study, we present that a vein–membrane interaction (VMI) can clarify this mechanical process. In order to investigate the VMI, we propose a numerical method that consists of (a) a shape simplification model wing that consists of a few beams and a rectangular shell structure as the structural essence of flapping insect wings for the VMI, and (b) a monolithic solution procedure for strongly coupled beam and shell structures with large deformation and large rotation to analyze the shape simplification model wing. We incorporate data from actual insects into the proposed numerical method for the VMI. In the numerical analysis, we demonstrate that the model wing can generate a camber equivalent to that of the actual insects. Hence, the VMI will be a mechanical basis of the cambering of flapping insect wings. Furthermore, we present the mechanical roles of the veins in cambering. The intermediate veins increase the out-of-plane deflection of the wing membrane due to the aerodynamic pressure in the central area of the wing, while they decrease it in the vicinity of the trailing edge. As a result, these veins create the significant camber. The torsional flexibility of the leading-edge veins increases the magnitude of cambering.

DOI： 10.3390/biomimetics8080571

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Computational fluid–structure interaction framework for passive feathering and cambering in flapping insect wings 査読有り国際誌

Ishihara D., Onishi M.

International Journal for Numerical Methods in Fluids 96 ( 4 ) 435 - 481 2023年11月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In flapping insect wings, veins support flexible wing membranes such that the wings form feathering and cambering motions passively from large elastic deformations. These motions are essentially important in unsteady aerodynamics of insect flapping flight. Hence, the underlying mechanism of this phenomenon is an important issue in studies on insect flight. Systematic parametric studies on strong coupling between a model wing describing these elastic deformations and the surrounding fluid, which is a direct formulation of this phenomenon, will be effective for solving this issue. The purpose of this study is to develop a robust numerical framework for these systematic parametric studies. The proposed framework consists of two novel numerical methods: (1) A fully parallelized solution method using both algebraic splitting and semi-implicit scheme for monolithic fluid–structure interaction (FSI) equation systems, which is numerically stable for a wide range of properties such as solid-to-fluid mass ratios and large body motions, and large elastic deformations. (2) A structural mechanics model for insect flapping wings using pixel modeling (pixel model wing), which is combined with explicit node-positioning to reduce computational costs significantly in controlling fluid meshes. The validity of the proposed framework is demonstrated for some benchmark problems and a dynamically scaled model incorporating actual insect data. Finally, from a parametric study for the pixel model wing flapped in fluid with a wide range of solid-to-fluid mass ratios, we find a FSI mechanism of feathering and cambering motions in flapping insect wings.

DOI： 10.1002/fld.5251

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共振駆動される昆虫規範型微小飛行体の羽ばたき飛行性能評価

白川和, 石破和弥, 木村元宣, 石原大輔

[No.23-49] 日本機械学会第14回マイクロ・ナノ工学シンポジウム予稿集〔2023.11.6－9，熊本〕 2023年11月

圧電-逆圧電-構造連成現象の動解析における分離反復型解法の収束特性

日浦巧稀, 岩丸直樹, 相川昇壱, 石原大輔

計算力学講演会講演論文集[No.23-24] 日本機械学会第 36 回計算力学講演会（CMD2023） ( 一般社団法人日本機械学会 ) OS-0202 2023年10月

Numerical Analysis of Insect Flight Maneuverability Using Feedback Control Model 査読有り

Kaede Sugikawa, Minato Onishi, Daisuke Ishihara

Proceedings of the 42nd JSST Annual International Conference on Simulation Technology 155 - 158 2023年08月

流体中で振動する圧電バイモルフにおける流体-構造-圧電- 電気回路連成現象のハイブリッド型強連成解法

三笘征弘, 野崎隼之介, 石原大輔

計算工学講演会論文集 G-01-04 2023年05月

FIRST PROTOTYPE OF POLYMER MICROMACHINED FLAPPING WING NANO AIR VEHICLE 査読有り国際誌

Rashmikant, Ryotaro Suetsugu, Minato Onishi, and Daisuke Ishihara

Proceedings of 2023 IEEE 36th International Conference on Micro Electro Mechanical Systems (MEMS) 2023-January 534 - 537 2023年03月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The novelty of this study includes the development of an insect-inspired flapping wing nano air vehicle (FWNAV) using polymer micromachining or MEMS flyer and its computational flight performance using a fluid-structure interaction (FSI) analysis. The present FWNAV consists of a micro transmission with a support frame, a micro wing, and a piezoelectric bimorph actuator. This FWNAV can be easily fabricated using polymer micromachining and its flight performance can be accurately predicted using the FSI analysis. Hence, this study will lead toward the development of tethered and flyable FWNAVs with the size of the smallest flying natural insects.

DOI： 10.1109/MEMS49605.2023.10052580

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Importance of Three-Dimensional Piezoelectric Coupling Modeling in Quantitative Analysis of Piezoelectric Actuators 査読有り国際誌

Daisuke Ishihara, Prakasha Chigahalli Ramegowda, Shoichi Aikawa, Naoki Iwamaru

CMES - Computer Modeling in Engineering and Sciences ( Tech Science Press ) 136 ( 2 ) 1187 - 1206 2023年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper demonstrates the importance of three-dimensional (3-D) piezoelectric coupling in the electromechanical behavior of piezoelectric devices using three-dimensional finite element analyses based on weak and strong coupling models for a thin cantilevered piezoelectric bimorph actuator. It is found that there is a significant difference between the strong and weak coupling solutions given by coupling direct and inverse piezoelectric effects (i.e., piezoelectric coupling effect). In addition, there is significant longitudinal bending caused by the constraint of the inverse piezoelectric effect in the width direction at the fixed end (i.e., 3-D effect). Hence, modeling of these effects or 3-D piezoelectric coupling modeling is an electromechanical basis for the piezoelectric devices, which contributes to the accurate prediction of their behavior.

DOI： 10.32604/cmes.2023.024614

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Iterative design window search for polymer micromachined flapping-wing nano air vehicles using nonlinear dynamic analysis 査読有り国際誌

Rashmikant, Daisuke Ishihara

International Journal of Mechanics and Materials in Design ( Springer Science and Business Media B.V. ) 19 ( 2 ) 407 - 429 2023年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, an iterative design window (DW) search using nonlinear dynamic simulation was proposed for polymer micromachined flapping-wing nano air vehicles (FWNAVs) that can satisfy both nonlinear and unsteady design requirements, which are contradictory to each other. The DW is defined as an existing area of satisfactory solutions in the design parameter space. The present FWNAVs have a complete 2.5-dimensional structure such that they can be fabricated using polymer micromachining. The micro-wing of our FWNAVs has been designed using morphological and kinematic parameters of an actual dipteran insect. Finally, using our method, we found the DW that allowed miniaturization of the design down to 10 mm while satisfying all the design requirements. Our findings demonstrate the possibility of further miniaturizing FWNAVs down to the size of small flying insects.

DOI： 10.1007/s10999-022-09635-4

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Computational control for strongly coupled structure, electric, and fluid systems 査読有り国際誌

Shankar V., Ramegowda P.C., Ishihara D.

International Journal for Computational Methods in Engineering Science and Mechanics 24 ( 2 ) 91 - 106 2023年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Piezoelectric-structure interaction (PSI) and fluid-structure interaction (FSI) are multi-physics coupled systems. These interactions affect the vibration characteristics of coupled systems and thus such complex coupled systems must be controlled. This paper proposes computational control based on the finite element method for strongly coupled multi-physics analysis of the PSI of a thin flexible piezoelectric bimorph actuator. The vibration characteristics and the effect of direct velocity and displacement feedback (DVDFB) control in coupled systems are investigated. The displacement and velocity feedback gains are used together as well as separately. DVDFB control is extended to the FSI of stiff and soft structures to study vibration characteristics using active control and compare the stability of the two types of structure. The results of PSI show a reduction in actuator displacement amplitude and a shift in the resonance frequency due to DVDFB control. For FSI, the results for a stiff material show a reduction in displacement. The velocity feedback gain has no effect for a stiff material and leads to instability due to a large control force. The results for a soft material show a reduction in displacement and amplitude and more stability compared to the case for the stiff material.

DOI： 10.1080/15502287.2022.2066032

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圧電-逆圧電-構造連成現象の動解析における分離反復型解法の収束特性

日浦巧稀, 岩丸直樹, 相川昇壱, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2023.36 ( 0 ) OS-0202 2023年01月

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

In a micro piezoelectric drive system for insect-mimetic flapping wing nano air vehicles, a small translational displacement of the piezoelectric bimorph is converted to a large angular displacement using a transmission based on the geometric nonlinearity of large bending of the elastic hinges. The piezoelectric bimorph and the transmission strongly interact with each other due to the scale effect. Furthermore, in the piezoelectric bimorph, the direct and inverse piezoelectric effects are coupled with each other. Hence, in the micro piezoelectric drive system, the direct-piezoelectric, inverse-piezoelectric, and structural coupling occurs. In this study, a finite element analysis method based on the block successive under-relaxation method is proposed for the dynamic analysis of this triply coupled phenomena, and the dependency of the convergence property on the relaxation coefficient is investigated.

DOI： 10.1299/jsmecmd.2023.36.os-0202

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2023.36/0/2023.36_OS-0202/_pdf

Accurate finite element modeling of multilayered flexible piezoelectric energy harvesting devices with strong coupling of structure, piezoelectricity, and circuit 査読有り国際誌

Ramegowda P.C., Ishihara D.

International Journal for Computational Methods in Engineering Science and Mechanics ( Informa UK Limited ) 25 ( 3 ) 137 - 151 2023年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Multilayered flexible piezoelectric energy harvesting devices (FPEDs) are a new future harvesting technology which are highly flexible and lightweight than familiar cantilever piezoelectric energy harvesters. This mechanical vibration driven FPED is a strongly coupled multiphysics phenomena that involve complex natural three-way interaction among the composite piezoelectric structure, the electric charge accumulated in the piezoelectric material, and a controlling electrical circuit attached to it. Efficient and accurate computational solution approaches are essential for analyzing these mechanical vibration-driven FPEDs to capture the main physical aspect of the coupled phenomena and to accurately predict the output voltage. While there are some numerical models for simple familiar cantilever type piezoelectric energy harvester reported in the literature, a fully three-dimensional strongly coupled model for complex material distributed, complex geometry, and multilayered FPED involving strong coupling of structure, piezoelectricity, and circuit phenomena has not yet been developed. A partitioned iterative algorithm is developed using a hierarchical decomposition approach wherein the coupled three fields are solved separately and coupled through loop union integration techniques that provide an efficient and accurate simulation of FPEDs. The simulation results matched the experiment results very well. This study provides a basis for the natural extension of partitioned iterative finite element coupled algorithm to simulate the future piezoelectric energy harvesting technologies involving a strong coupling of structure, piezoelectricity, and circuit phenomenon.

DOI： 10.1080/15502287.2023.2291013

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Computational evaluation of flight performance of flapping-wing nano air vehicles using hierarchical coupling of nonlinear dynamic and fluid-structure interaction analyses 査読有り国際誌

Rashmikant , Onishi M., Sugikawa K., Ishihara D.

Engineering Applications of Computational Fluid Mechanics 17 ( 1 ) 2023年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study endeavours to introduce an inventive hierarchical coupling methodology for evaluating the flight capabilities of polymer micromachined flapping-wing nano air vehicles (FWNAVs) using advanced computational tools. Furthermore, our objective is to provide a practical demonstration of FWNAVs in both tethered and airborne scenarios. These dual objectives represent the distinctive and pioneering aspects of this research. Such FWNAVs, which are insect-inspired robots, have a 2.5-dimensional structure. An FWNAV comprises a micro piezoelectric drive system and a pair of micro thin flexible wings. The drive system includes a micro transmission and a piezoelectric bimorph actuator. The flight performance of the designed FWNAV is evaluated using a hierarchical coupling approach, where the whole system is decomposed into a micro wing and a micro piezoelectric drive system. The coupling between these parts is modelled as one-way coupling and that between the micro wings and the surrounding air is modelled as strong coupling. In the one-way coupling analysis, nonlinear structural dynamic analysis is conducted for the micro piezoelectric drive system, where the dynamic response is transmitted to the micro wings via the Dirichlet boundary condition. In the strong coupling analysis, strongly coupled fluid-structure interaction analysis is conducted for the micro wings and the surrounding air to consider their strong coupling. The optimisation of flight performance is conducted using fluid-structure interaction analysis to achieve sufficient lift force to support the weight of an FWNAV. The design of a tethered and flyable FWNAV with a size of 10 mm or smaller is demonstrated. This FWNAV can be easily fabricated using polymer micromachining.

DOI： 10.1080/19942060.2023.2271053

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ポリマーマイクロマシニングによる昆虫規範型マイクロ弾性翼の作製可能解

白川和, ヴィナイシャンカー, 木村元宣, 石原大輔

バイオフロンティア講演会講演論文集 ( 一般社団法人日本機械学会 ) 2023.34 ( 0 ) 1F10 2023年01月

Numerical Analysis of Insect Flight Maneuverability Using Feedback Control Model 査読有り国際誌

石原大輔

Proceedings of the 42th JSST Annual International Conference on Simulation Technology - 155 - 158 2023年01月

ポリマー微細加工された昆虫規範型羽ばたき装置による微小翼の共振駆動

石破和弥, 末次亮太郎, 木村元宣, 大西南斗, 石原大輔

第13回マイクロ・ナノ工学シンポジウム予稿集 2022年11月

ポリマー微細加工による多層中空構造を用いた昆虫規範型飛行体用トランスミッション

木村元宣, 末次亮太郎, 上尾純平, 石原大輔

第13回マイクロ・ナノ工学シンポジウム予稿集 2022年11月

昆虫飛行操縦性における流体-翼-胴体連成のフィードバック制御付き分離型解法

大西南斗, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2022年11月

流体中で振動する圧電バイモルフにおける流体-構造-圧電-回路連成現象の分離反復型解法

三笘征弘, 野崎駿之介, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2022年11月

マイクロ圧電駆動システムの圧電-逆圧電-構造連成現象に対する分離反復型解法

岩丸直樹, 相川昇壱, 大西南斗, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2022年11月

ミクロスケール接触変形・電流連成解析による接触電気抵抗特性の基礎的検討

二保知也, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2022年11月

Fluid-structure interaction design of the polymer micromachined insect-inspired flapping wings 査読有り

Vinay Shankar, Minato Onishi, Daisuke Ishihara

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

Finite element analysis of multilayered flexible piezoelectric energy harvesting devices using strongly coupled structure-piezoelectric-circuit interaction 招待有り査読有り

Prakasha Chigahalli Ramegowda, Daisuke Ishihara, Rei Takata, Naoto Takayama, Tomoya Niho, Tomoyoshi Horie

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

Effect of wing’s mass distribution on the aerodynamic performance in insect flapping wings 査読有り

Minato Onishi, Daisuke Ishihara

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

Partitioned-Monolithic Hybrid Strongly Coupled Method for Structure-Piezoelectric-Circuit Interaction in Piezoelectric Energy Harvesting 査読有り

Shunnosuke Nozaki, Daisuke Ishihara, Tomoya Niho

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

Determination of Resonant Mechanism of Polymer Micromachined Insect Inspired Flapping Device Using Finite Element Modal Analysis 査読有り

Kazuya Ishiba, Minato Onishi, Daisuke Ishihara

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

Flight performance evaluation of polymer micromachined flapping-wing nano air vehicle using fluid-structure interaction analysis 査読有り

Rashmi Kant, Daisuke Ishihara, Minato Onishi

Proceedings of the 41st JSST Annual International Conference on Simulation Technology 2022年09月

連成解析・連携解析招待有り

山田知典, 澤田有弘, 石原大輔

計算工学 ( 日本計算工学会 ) 27 ( 3 ) 4014 (8) - 4015 (8) 2022年08月

圧電エネルギーハーベスティングにおける構造－圧電－回路連成現象の分離型-一体型ハイブリッド強連成解法の提案

野崎隼之介, 石原大輔, 二保知也

計算工学講演会論文集 2022年06月

2.5-dimensional insect-mimetic wing model for flapping wing nano air vehicles and design window search for manufacturable solutions using polymer micromachining 査読有り国際誌

Shankar V., Matsuo R., Onishi M., Ishihara D.

17th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2022 306 - 311 2022年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Insect flapping wings undergo large deformations such as feathering and cambering for creating large thrust forces. Hence, insect-mimetic wings for flapping wing nano air vehicles (FWNAVs) will replicate these characteristic deformations. For the purpose of realizing this type of wings, in this study, a 2.5-dimensional (2.5-D) insect-mimetic wing model for FWNAVs is proposed. The proposed wing model consists of the leading-edge, the central vein, the root vein, and the membrane, all of which are described by shell elements. The feathering and cambering of the proposed wing model can be caused by the aerodynamic pressure. Furthermore, the proposed wing can be fabricated using polymer micromachining because of the complete 2.5-D structure. In order to demonstrate these capabilities, we perform the design window (DW) search. The DW is defined as the existing area of satisfactory design solutions in the design parameter space, where each solution can produce a sufficient camber. The DWs for the leading-edge, the central and root veins are searched continuously using the geometrically nonlinear finite element analysis under quasi-steady aerodynamic modeling. The thickness is chosen as the design parameter, while the other parameters are set following actual insects and polymer materials. Finally, we determine the final solutions from the DWs for a specific polymer micromachining technique. In our future work, the proposed solutions will be manufactured for the future miniaturization of FWNAVs.

DOI： 10.1109/NEMS54180.2022.9791094

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85133478841&origin=inward

Computational Approach for the Fluid-Structure Interaction Design of Insect-Inspired Micro Flapping Wings 査読有り国際誌

Ishihara D.

Fluids 7 ( 1 ) 2022年01月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A flight device for insect-inspired flapping wing nano air vehicles (FWNAVs), which consists of the micro wings, the actuator, and the transmission, can use the fluid-structure interaction (FSI) to create the characteristic motions of the flapping wings. This design will be essential for further miniaturization of FWNAVs, since it will reduce the mechanical and electrical complexities of the flight device. Computational approaches will be necessary for this biomimetic concept because of the complexity of the FSI. Hence, in this study, a computational approach for the FSI design of insect-inspired micro flapping wings is proposed. This approach consists of a direct numerical modeling of the strongly coupled FSI, the dynamic similarity framework, and the design window (DW) search. The present numerical examples demonstrated that the dynamic similarity framework works well to make different two FSI systems with the strong coupling dynamically similar to each other, and this framework works as the guideline for the systematic investigation of the effect of characteristic parameters on the FSI system. Finally, an insect-inspired micro flapping wing with the 2.5-dimensional structure was designed using the proposed approach such that it can create the lift sufficient to support the weight of small insects. The existing area of satisfactory design solutions or the DW increases the fabricability of this wing using micromachining techniques based on the photolithography in the micro-electro-mechanical systems (MEMS) technology. Hence, the proposed approach will contribute to the further miniaturization of FWNAVs.

DOI： 10.3390/fluids7010026

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85123772660&origin=inward

昆虫飛行操縦性における流体-翼-胴体連成のフィードバック制御付き分離型解法

大西南斗, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2022.35 ( 0 ) 12-07 2022年01月

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

This study proposed a partitioned method with a feedback control to analyzed maneuvering of insects during flapping flight. This method decomposed the insect flapping flight into wing and body subsystems and then coupled them using feedback control. In the wing subsystem, the strong coupling of the flexible wings and surrounding fluid was accurately analyzed using the finite element method to obtain the thrust forces acting on the insect’s body. The resulting thrust forces were passed from the wing subsystem to the body subsystem, and then rigid body motion was analyzed in the body subsystem. The controlling of wing subsystem is done by the feedback control using the body angular displacement and velocity. The fundamental performance of the proposed method is demonstrated from the comparison between the present results and the actual observation of maneuver.

DOI： 10.1299/jsmecmd.2022.35.12-07

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2022.35/0/2022.35_12-07/_pdf

One-wing polymer micromachined transmission for insect-inspired flapping wing nano air vehicles 査読有り

Rashmikant , Ishihara D., Suetsugu R., Ramegowda P.C.

Engineering Research Express 3 ( 4 ) 2021年12月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper presents a feasibility step in the development of an insect-inspired flapping wing nano air vehicle using advanced engineering technologies such as microelectromechanical systems (MEMS) technologies. To develop an insect-inspired flapping wing nano air vehicle, a one-wing polymer micromachined transmission is proposed in this paper. The novelty of this study includes (1) the use of the geometrically nonlinear bending deformation of a set of two parallel elastic hinges as the basis for the transmission mechanism, which produces a large rotational displacement from a small translational displacement, and (2) a complete 2.5-dimensional structure that can be fabricated using standard microfabrication techniques, including etching, photolithography, deposition, and curing, without any post-assembly. This design is also an improved version of our previous design, a two-wing polymer micromachined transmission. The transmission proposed here has a great advantage over other types of transmission mechanisms, including its low energy loss because no post-assembly is required (reduced friction loss); its low total weight; its capacity to be further miniaturized without difficulty; and its performance, i.e., ability to produce the necessary stroke angle of approximately 30° without resonance assistance.

DOI： 10.1088/2631-8695/ac2bf0

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85123166485&origin=inward

Comparative study on linear and quadratic solid direct-piezoelectric solvers with shell inverse-piezoelectric solver to analyze a thin piezoelectric bimorph device 査読有り

Prakasha Chigahalli Ramegowda, Daisuke Ishihara

Proceedings of the 40th JSST Annual International Conference on Simulation Technology 406 - 409 2021年09月

Importance of 3-D piezoelectric coupled analysis in evaluation of thin piezoelectric bimorph deformation 査読有り

Shoichi Aikawa, Daisuke Ishihara, Naoki Iwamaru, Prakasha Chigahalli Ramegowda

Proceedings of the 40th JSST Annual International Conference on Simulation Technology 404 - 405 2021年09月

Comparative study on partitioned iterative algorithms for coupled multiple phenomena in piezoelectric energy harvesters 査読有り

Naoto Takayama, Daisuke Ishihara, Prakasha Chigahalli Ramegowda, Shunsuke Nozaki

Proceedings of the 40th JSST Annual International Conference on Simulation Technology 378 - 379 2021年09月

Passive motions and aerodynamic performance of insect’s flapping wings simulated using the pixel wing model and the strong coupling method 査読有り

Minato Onishi, Daisuke Ishihara

Proceedings of the 40th JSST Annual International Conference on Simulation Technology 374 - 377 2021年09月

Comparative study of strongly coupled fluid and structure systems with computational control 査読有り

Vinay Shankar, Daisuke Ishihara

Proceedings of the 40th JSST Annual International Conference on Simulation Technology 370 - 373 2021年09月

Strongly coupled partitioned iterative method for the structure–piezoelectric–circuit interaction using hierarchical decomposition 査読有り

Ishihara D., Takata R., Ramegowda P.C., Takayama N.

Computers and Structures 253 2021年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

The key to the design of advanced micro electro–mechanical devices is an accurate evaluation of the circuit-integrated piezoelectric oscillator that accounts for its complicated configuration. Here, the direct numerical modeling of this oscillator leads to a general formulation as a structure–piezoelectric–circuit interaction. Hence, this study developed a strongly coupled partitioned iterative method for the structure–piezoelectric–circuit interaction. The proposed method was constructed using hierarchical decomposition, the partitioned iterative method for two coupled fields, and loop union. That is, the whole system of the coupled multiphysics is hierarchically decomposed into coupled two-field subsystems, partitioned iterative algorithms for two coupled fields are applied to these subsystems, and the coupling algorithms for these subsystems are reduced to a single coupling algorithm. In the proposed method, three distinct direct piezoelectric, inverse piezoelectric, and circuit solvers are strongly coupled with each other. The inverse piezoelectric solver uses shell finite elements to analyze the response of the thin oscillator efficiently, while the direct piezoelectric solver uses solid finite elements to accurately describe the three-dimensional distribution of the electric potential in the piezoelectric continuum. The proposed method can accurately analyze coupling phenomena in the RC circuit, piezoelectric shunt damping, and piezoelectric energy harvesting.

DOI： 10.1016/j.compstruc.2021.106572

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85107056686&origin=inward

抵抗スポット溶接における引張せん断強度の接触変形・電流・熱伝導3 連成解析

二保知也, 金城喜己, 石原大輔

計算工学講演会論文集 26 A-11-06 (3pages) 2021年05月

圧電エネルギーハーベスティングの複合・階層的な構造–圧電–電気回路連成現象に対する分離反復型解法の比較検討

高山直人, 石原大輔, プラカシャチガハリラメゴウダ, 野崎隼之介

計算工学講演会論文集 26 A-11-03 (4pages) 2021年05月

圧電バイモルフ変形評価における３次元圧電-逆圧電連成解析の重要性

相川昇壱, 石原大輔, 岩丸直樹, プラカシャチガハリラメゴウダ

計算工学講演会論文集 26 A-11-02 (3pages) 2021年05月

昆虫羽ばたき翼に生じる受動的キャンバーのピクセル翼モデルによる流体構造連成解析

大西南斗, 石原大輔

計算工学講演会論文集 26 A-10-02 (3pages) 2021年05月

Improved Design of Polymer Micromachined Transmission for Flapping Wing Nano Air Vehicle 査読有り国際誌

Rashmikant , Ishihara D., Suetsugu R., Murakami S., Ramegowda P.C.

Proceedings of the 16th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2021 1320 - 1325 2021年04月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents an improved design of polymer micromachined transmission for flapping-wing Nano Air Vehicles (FWNAVs) in comparison with our last design. Design Improvement includes (1) reduction of the crack and fracture during microfabrication, and (2) performance improvement of the transmission. The novelty of our polymer micromachined transmission includes (1) the transmission mechanism based on the geometrical nonlinear bending deformation, and (2) the complete 2.5-dimensional structure that can be fabricated using standard microfabrication techniques including the etching, the photolithography, the deposition, and the curing process. The complete 2.5-dimensional structure requires no post-assembly and leads to further miniaturization without so much difficulty. Each wing of FWNAVs will be driven by the proposed transmission and actuator separately. The present transmission can produce around 40° stroke angle, which is about 50% higher than that of our previous work without considering the mass effect.

DOI： 10.1109/NEMS51815.2021.9451440

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85113350665&origin=inward

Hierarchical modeling and finite element analysis of piezoelectric energy harvester from structure-piezoelectric-circuit interaction 査読有り

Ramegowda P.C., Ishihara D., Takata R., Horie T.

World Congress in Computational Mechanics and ECCOMAS Congress 1200 2021年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The piezoelectric energy harvesting devices for the conversion of mechanical vibration into electric energy via a flexible piezoelectric energy harvesting (FPED) structure have gained greater attention. Here, the large deformation of the FPED structure causes a strong interaction with the electric field (direct-piezoelectric effect) and structural field (inverse-piezoelectric effect), and vice-versa. Also an electrical circuit is attached to the electrodes covering the piezoelectric layers. This becomes a three-way coupling of the structure, the electromechanical effect of the piezoelectric material, and the electrical circuit. A mathematical and numerical model of the complex physical system of the involved multiphysics coupling characteristics in order to predict the operational properties and to increase the performance is very important. The presentation will discuss a partitioned coupling algorithm based hierarchical decomposition using finite element method for piezoelectric energy harvesting from structure-piezoelectric-circuit interaction. Results obtained with the finite element analysis are compared with the experimental results of PEHDs with base excitation reported in the literature.

DOI： 10.23967/wccm-eccomas.2020.163

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85122159991&origin=inward

Triply coupled analysis method for thin flexible piezoelectric bimorph in fluid 査読有り国際誌

Ramegowda P.C., Ishihara D., Takata R., Niho T., Horie T.

8th International Conference on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2019 470 - 480 2021年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Piezoelectric-structure-fluid interaction is a complex multiphysics coupled phenomena appears wherein piezoelectric devices are in contact or surrounded by the fluid media. The piezoelectric energy harvesting using ocean waves, wind flow, and mechanical vibrations are some of the popular energy savaging methods wherein thin piezoelectric bimorphs surrounded by the fluid is used for power harvesting. With recent advances on micro air vehicles actuated by piezoelectric bimorph actuators in the fluid (surrounding media) as attracted the of piezoelectric-structure-fluid interaction. Generally, in these applications, the piezoelectric bimorph is thin, flexible, and surrounded by the fluid. The large deformation of the thin flexible piezoelectric bimorph causes strong interaction with the electric field (piezoelectric effect) and the surrounding fluid, and inversely, these two fields significantly affect the structure. The piezoelectric field-structure-fluid interaction analysis is very significant. In this work, we propose a hierarchal decomposition method to solve piezoelectric-structure-fluid interaction of a piezoelectric bimorph in the fluid. The proposed method is applied to a flexible restrictor flap in converging channel, where the rubber flap is replaced by the piezoelectric bimorphs made of PVDF or PZT-5H. The resonance frequency of the piezoelectric bimorph in the fluid agrees well with the theoretical and numerical pure FSI cases. These results show a good agreement with the previous studies.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85102122633&origin=inward

Coupled solid piezoelectric and shell inverse-piezoelectric analysis using partitioned method for thin piezoelectric bimorph with metal layers 査読有り国際誌

Ishihara D., Ramegowda P.C., Takata R., Niho T., Horie T.

8th International Conference on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2019 451 - 457 2021年01月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this study, the coupled solid piezoelectric and shell inverse-piezoelectric analysis method for a thin piezoelectric bimorph with metal layers is proposed. The piezoelectric bimorph is usually thin and includes the metal layers such as the electrode and the shim plate. In the proposed method, the solid and shell elements are used for the piezoelectric and inverse-piezoelectric analyses, respectively, since the solid elements can describe the various types of the distributions of the electric potential along the thickness, and the shell elements are suitable for analyzing the thin structure. The block Gauss-Seidel method is used to couple the solid piezoelectric and shell inverse-piezoelectric analyses. In the iterative passing of the solution variables, the transformation method is used between the solid and shell elements. The rules of mixture for the bending rigidity and the mass are used for modeling the single shell structure in the inverse-piezoelectric analysis. A pseudo-piezoelectric modeling for the conductor is proposed to consider the metal layers in the piezoelectric analysis. This modeling allows us to reuse existing programs of the piezoelectric analysis without any modification.

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Performance evaluation of the pixel wing model for the insect wing's camber 招待有り査読有り

Onishi Minato, Ishihara Daisuke

日本シミュレーション学会英文誌 ( 一般社団法人日本シミュレーション学会 ) 8 ( 2 ) 163 - 172 2021年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In insect flapping wings, the camber deformation is caused by the aerodynamic forces. Since the camber will improve the aerodynamic performance of Flapping Wing Nano Air Vehicles (FWNAVs), it is important to elucidate the passive mechanism of the cambering. The pixel wing model consisting of a structured mesh using shell elements that can simulate the camber deformation caused by the fluid–structure interaction has been proposed for the purpose of computational efficiency. In this study, the performance of the pixel wing model is evaluated as the pixel model resolution is changed. The minimum pixel model resolution is determined such that it can keep enough magnitude of camber compared to actual insects. Furthermore, it is found that the cambering of the pixel wing model can be effectively changed using the wing's chord-wise flexural stiffness given by the root vein pixels and the thickness of the wing membrane pixels.

DOI： 10.15748/jasse.8.163

その他リンク： https://ci.nii.ac.jp/naid/130008062974

炭素繊維複合材およびドライクロスの誘導加熱解析査読有り

中村俊太, 堀江知義, 二保知也, 石原大輔

日本AEM学会誌 ( 日本AEM学会 ) 29 ( 3 ) 576 - 582 2021年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Heating analysis of CFRP and carbon fiber dry cloth for aircraft structures, which is expected for a medium-sized aircraft, is performed. Comparing the temperature of test pieces between numerical and experimental results, validity of both experimental and analytical methods is confirmed for both aluminum and carbon dry cloth sheet. Analysis is made for the layers of carbon dry cloth sheet and CFRTP plate.

DOI： 10.14243/jsaem.29.576

その他リンク： https://ci.nii.ac.jp/naid/130008142891

電気機械システムの圧電ー逆圧電ー構造連成現象に対する分離反復型解法に関する研究

相川昇壱, 石原大輔, 熊谷武尊, 岩丸直樹, プラカシャラメゴウダ, 大西南斗

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2021.34 ( 0 ) 249 2021年01月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

In micro-electro-mechanical systems using piezoelectric bimorph actuators such as FWNAV, small displacements given by the actuators can be magnified using a transmission using the flexible structure. Hence, in these systems, coupling among the direct and inverse piezoelectric effects, and the flexible structure occurs. In this study, a partitioned iterative method is proposed based on the block SUR algorithm for this strongly coupled problem, and the basic performances are demonstrated in numerical examples.

DOI： 10.1299/jsmecmd.2021.34.249

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2021.34/0/2021.34_249/_pdf

誘導加熱による炭素繊維複合材成形のための電磁場・熱伝導連成解析

二保知也, 中村俊太, 石原大輔, 堀江知義, 神原信幸, 志谷徹

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2021.34 ( 0 ) 130 2021年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Bonding and forming of carbon fiber reinforced plastic by induction heating are required for medium-sized aircraft manufacturing. In this paper, electromagnetic and thermal conduction coupled finite element analysis method is described for induction heating of carbon fiber dry cloth. Experiments of induction heating are also performed to discuss the validity of analysis method and experimental method. Comparing the temperature of test pieces between analysis and experimental results, validity of both methods is confirmed for both aluminum sheet and carbon fiber dry cloth.

DOI： 10.1299/jsmecmd.2021.34.130

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2021.34/0/2021.34_130/_pdf

昆虫羽ばたき翼の空力性能に対する受動的キャンバーの影響

大西南斗, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2021.34 ( 0 ) 176 2021年01月

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

Any shape change of insect’s wings during their flapping motion will be passively caused by external forces such as the inertial and aerodynamic forces because the wings have no interior muscle. The camber deformation, which is the focus of this study, plays an important role in the aerodynamic performance of the insect’s flapping flight. In this study, the effect of passive cambering is investigated using a fluid-structure interaction analysis and a pixel wing model using only structured shell elements, which adequately simulates the camber deformation in actual insects.

DOI： 10.1299/jsmecmd.2021.34.176

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2021.34/0/2021.34_176/_pdf

圧電エネルギーハーベスティングにおける構造−圧電−電気回路相互作用に対する連成アルゴリズムの比較検討

高山直人, 石原大輔, Prakasha Chigahalli Ramegowda, 大西南斗

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2021.34 ( 0 ) 210 2021年01月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

In recent years, energy harvesting from environment has attracted much attention. In particular, piezoelectric bimorph energy harvesters, which are effective as an energy source for MEMS, have been widely studied. In piezoelectric energy harvesters, structure, piezoelectricity, and circuit are strongly coupled in a complicated and hierarchical manner. For the three-field coupling phenomena, unlike two-field coupling phenomena, various partitioned algorithms are possible. Hence, in this study, we develop three partitioned algorithms using hierarchical decomposition: In the first algorithm, all fields are solved implicitly or strongly coupled using the block Gauss-Seidel (BGS) method (fully strong coupling algorithm). In the second algorithm, the structure-piezoelectric interaction is solved implicitly or strongly coupled using the BGS method, and the circuit is solved explicitly or weakly coupled (partially strong coupling algorithm). In the third algorithm, all fields are solved explicitly or weakly coupled (fully weak coupling algorithm). These methods are applied to a typical piezoelectric harvester, namely a cantilevered piezoelectric bimorph, and their performances such as the accuracy and the computational cost are discussed.

DOI： 10.1299/jsmecmd.2021.34.210

その他リンク： https://www.jstage.jst.go.jp/article/jsmecmd/2021.34/0/2021.34_210/_pdf

A Design Window Search Using Nonlinear Dynamic Simulation for Polymer Micro-machined Transmission in Insect-inspired Flapping wing Nano Air Vehicles 査読有り国際誌

Rashmikant , Ishihara D.

2021 6th International Conference on Robotics and Automation Engineering, ICRAE 2021 162 - 167 2021年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The novelty of this study is the proposition of a design window (DW) search using the nonlinear dynamic simulation, and the finding of the DWs of the polymer micro transmission that satisfies the nonlinear and unsteady design requirements conflicting with each other simultaneously. Here, the DW is defined as an existing area of satisfactory solutions in a design parameter space, which is defined as the flapping frequency equivalent to small flies and the mass of the micro wing supported by the transmission design. Since this micro transmission is the key component of the flapping wing nano air vehicle (FWNAVs) which has a 2.5-D structure and is fabricated using polymer micromachining so proposed DWs will contribute to further miniaturizing FWNAVs.

DOI： 10.1109/ICRAE53653.2021.9657802

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85124796665&origin=inward

HIERARCHICALLY DECOMPOSED FINITE ELEMENT METHOD FOR THE COUPLED FOUR FIELDS OF THE FLUID-STRUCTURE-PIEZOELECTRIC-CIRCUIT INTERACTION 査読有り国際誌

Ramegowda P.C., Ishihara D.

9th International Conference on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2021 2021年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

A partitioned iterative method based on hierarchical decomposition is proposed for providing numerical modeling and analysis of the piezoelectric energy harvester which is involved in coupled fluid-structure interaction, coupled electro-mechanical, and a controlling electrical circuit for piezoelectric structural applications in energy harvesting. This circuitintegrated piezoelectric structural application in energy harvesting surrounded by fluid media takes the form of natural four-way coupling of fluid flow, the structure, the electromechanical effect of the piezoelectric material, and the electrical circuit. This can be formulated exactly as a fluid-structure-piezoelectric-circuit interaction. These coupled four fields are hierarchically decomposed into the fluid-structure interaction, structure-piezoelectric interaction, and piezoelectric-circuit interaction interactions. Then these subsystems are decomposed into each field. The proposed finite element method enables to reuse of existing techniques because of its modularity. Furthermore, scalability to multiphysics and multisystem couplings is expected. There are some numerical approaches in particular monolithic coupling methods are studied which are computationally expensive and leads to an ill-conditioned coefficient matrix. Nevertheless, accurate modeling for predicting the characteristics of this four-way coupling using partitioned methods has not yet been developed. This method enables an investigation of piezoelectric structures in fluid with complex geometry, material composition, and attached electrical circuits to the harvester. A flexible piezoelectric bimorph harvester in the converging channel is analyzed to demonstrate the efficiency of the proposed method. The results indicate that the method captures the coupled effect accurately.

DOI： 10.23967/coupled.2021.031

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85206907959&origin=inward

COMPUTATIONAL FLUID-STRUCTURE INTERACTION FRAMEWORK FOR SIMULATING CHARACTERISTIC DEFORMATIONS IN INSECT FLAPPING WINGS 査読有り国際誌

Onishi M., Ishihara D.

9th International Conference on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2021 2021年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this study, a computational fluid-structure interaction (FSI) framework for characteristic deformations in insect's wings is proposed. The proposed framework consists of a pixel wing model using a structured shell finite element mesh, a projection method for the monolithic FSI monolithic equations using an algebraic splitting, and the FSI dynamic similarity law to measure dynamic similarity between model's and actual insect's flights. It is shown that the proposed framework can directly simulate passive feathering and cambering in insect's wings caused by the FSI, whose magnitudes are very close to those of actual insects.

DOI： 10.23967/coupled.2021.012

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圧電エネルギーハーベスティングにおける構造‐圧電‐回路連成現象の分離反復型解析

石原大輔, 高田黎, プラカシャチガハリラメゴウダ, 高山直人

日本機械学会計算力学部門 CMD2020計力スクウェア研究報告集 A-TS 01-27 Report No. 2-12, 5pages 2020年12月

昆虫羽ばたき翼に生じる特徴的弾性変形の流体構造連成解析

大西南斗, 大戸悠司, 石破和弥, 石原大輔

日本機械学会計算力学部門 CMD2020計力スクウェア研究報告集 A-TS 01-27 Report No. 2-13, 5pages 2020年12月

Polymer Micromachined Transmission for Insect-Inspired Flapping Wing Nano Air Vehicles* 査読有り

Ishihara D., Murakami S., Ohira N., Ueo J., Takagi M., Urakawa K., Horie T.

15th IEEE International Conference on Nano/Micro Engineered and Molecular System, NEMS 2020 176 - 179 2020年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2020 IEEE. This paper presents a polymer micromachined transmission from small translational displacement to large rotational displacement, which has the potential for further miniaturizing a variety of micro robot applications such as insect-inspired flapping wing nano air vehicles (FWNAVs). Innovative claims include (1) the transmission mechanism using a geometrically nonlinear bending, (2) the microfabrication process consisting of only the standard steps such as the deposition, the photolithography, the curing, and the release without any post-assembling, and (3) the stroke angle of about 40° without any dynamic effect.

DOI： 10.1109/NEMS50311.2020.9265594

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Finite element analysis of a thin piezoelectric bimorph with a metal shim using solid direct-piezoelectric and shell inverse-piezoelectric coupling with pseudo direct-piezoelectric evaluation 査読有り

Ramegowda P.C., Ishihara D., Takata R., Niho T., Horie T.

Composite Structures 245 2020年08月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Elsevier Ltd A thin triple-layer piezoelectric bender, also known as a piezoelectric bimorph with a metal shim, consists of an elastic layer (metal shim) sandwiched between two piezoelectric layers. It is one of the most commonly used piezoelectric composite structures in both sensing and actuation applications. Therefore, this study deals with the coupled piezoelectric-structure interaction analysis of a thin piezoelectric bimorph with a metal shim. In this work, the best features of the solid and shell elements were combined to analyze the piezoelectric and structural fields, respectively, in a thin piezoelectric bimorph with a metal shim. This approach addresses the shortcomings of using a single finite element mesh for both the piezoelectric and structural fields. A transformation method using the block Gauss-Seidel algorithm is employed to exchange the variables between solid direct-piezoelectric and shell inverse-piezoelectric analyses. The metal layer can be analyzed as an elastic body with electrical boundary conditions. A pseudo direct-piezoelectric evaluation method for the metal shim in the piezoelectric analysis is proposed. This method allows us to reuse the existing piezoelectric analysis program, where the metal shim is analyzed as the pseudo direct-piezoelectric material in a single analysis procedure. The homogenization method for the evaluation of bending rigidity and mass is used for modeling the single shell structure in the inverse-piezoelectric analysis of a thin piezoelectric bimorph with a metal layer. Numerical results are given for various electrical configurations of actuators and sensors to validate the present method. Comparison with an exact solution illustrates the accuracy, efficiency, and capability of the developed solid direct and shell inverse-piezoelectric analysis coupled with a pseudo direct-piezoelectric evaluation method to capture the sensor and actuator response of a thin piezoelectric bimorph with a metal shim.

DOI： 10.1016/j.compstruct.2020.112284

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Hierarchically decomposed finite element method for a triply coupled piezoelectric, structure, and fluid fields of a thin piezoelectric bimorph in fluid 査読有り

Ramegowda P.C., Ishihara D., Takata R., Niho T., Horie T.

Computer Methods in Applied Mechanics and Engineering 365 2020年06月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Elsevier B.V. This paper proposes a numerical method for analyzing a thin piezoelectric bimorph in fluid. A hierarchically decomposed finite element method (FEM) is proposed for modeling the triply coupled piezoelectric-structure–fluid interaction. The electromechanical coupling (piezoelectric-structure interaction) behavior in a thin piezoelectric bimorph is described by the classical constitutive equation, the incompressible fluid flows by the Navier–Stokes equation and the structure by the Cauchy equation of motion. The piezoelectric-structure–fluid interaction system is decomposed into subsystems of fluid–structure interaction (FSI) and piezoelectric field, then the piezoelectric field and the FSI are coupled using the block Gauss–Seidel method, the fluid–structure interaction is split into the fluid–structure velocity field and the pressure field using an algebraic splitting and the fluid–structure velocity field is partitioned into fluid velocity field and structure velocity field. Using the proposed method, the resonance characteristics of a piezoelectric bimorph cantilever made of PVDF and PZT-5H material in fluid are investigated for actuation and sensor configurations.

DOI： 10.1016/j.cma.2020.113006

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炭素繊維複合材およびドライクロスの誘導加熱解析

中村俊太，堀江知義，二保知也，石原大輔

第32回「電磁力関連のダイナミクス」シンポジウム講演論文集 65 - 70 2020年05月

電気結合係数の大きな圧電材料によるバイモルフ型アクチュエータに対する解析方法の比較検討

石原大輔，熊谷武尊，相川昇壱，プラカシャチガハリラメゴウダ，二保知也，堀江知義

第32回「電磁力関連のダイナミクス」シンポジウム講演論文集 75 - 76 2020年05月

Element-quality-based stiffening for the pseudoelastic mesh-moving technique 査読有り

Ishihara D., Goto A., Onishi M., Horie T., Niho T.

International Journal of Computational Methods 17 ( 4 ) 2020年05月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 World Scientific Publishing Company. In this study, element-quality-based stiffening (EQBS) was developed as a method of maintaining mesh quality in the pseudoelastic mesh-moving technique. The proposed EQBS technique increases the stiffness of the element based on two element quality parameters, the element area and shape; this differs from techniques used in previous studies. Importantly, EQBS includes the previously proposed Jacobian-based stiffening (JBS) and minimum height-based stiffening (MHBS) techniques as a specific case. Therefore, it is quite general scenario of the selective stiffening of the mesh. The proposed EQBS technique was applied to the mesh-moving of a rectangular domain including a structure consisting of a square and a fin that undergo large translations and rotations. The proposed EQBS technique showed better performance than JBS on test problems with large translations and rotations applied to the structure. This is because EQBS considers the shear deformation of the element in addition to the tensile and compressive deformations.

DOI： 10.1142/S0219876218501463

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Fluid-structure and electric interaction analysis of piezoelectric flap in a channel using a strongly coupled FEM scheme 査読有り

Ramegowda P.C., Ishihara D., Takata R., Niho T., Horie T.

Proceedings of the 6th European Conference on Computational Mechanics: Solids, Structures and Coupled Problems, ECCM 2018 and 7th European Conference on Computational Fluid Dynamics, ECFD 2018 382 - 393 2020年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Copyright © Crown copyright (2018).All right reserved. Electric and Fluid-Structure interaction (EFSI) is a complex coupled multi-physics phenomenon appears in microelectromechanical system (MEMS) when these microdevices are operated in a fluid media. In this study, the EFSI phenomena refer to a combination of electromechanical (electric-structure interaction) coupling and fluid-structure interaction coupling. Both the electromechanical coupling and the fluid-structure interaction can be simulated in a monolithic way or in a partitioned iteration way. In the proposed method the electromechanical coupling is simulated in a partitioned iterative way with separate solvers for the electrical and mechanical equations using block Gauss-Seidel (BGS) iteration method, while the fluid-structure interaction is simulated in a monolithic way by solving the fluid and structure equations simultaneously using a projection method. The proposed algorithm combines these two methods to analyze the strongly coupled EFSI in MEMS. The proposed method is applied to a flexible flap made of piezoelectric bimorph actuator in a converging channel. The EFSI analysis results show a good agreement with FSI results when a very low input bias voltage is applied to the actuator.

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逆圧電‐圧電‐電気回路連成現象の分離反復型解法査読有り

石原大輔, 高田黎, Prakasha Chigahalli Ramegowda

日本計算工学会論文集 ( 一般社団法人日本計算工学会 ) 2020 ( 0 ) 20200015 - 20200015 2020年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

アクチュエータやセンサに用いられる圧電バイモルフは，通常，電気回路に接続される．この場合，圧電バイモルフの機械的挙動は回路からの電荷の影響を受け，また圧電バイモルフは回路内でコンデンサのように振る舞う．ゆえに，圧電バイモルフを用いる電気機械システムの設計プロセスにおいて，逆圧電‐圧電連成に加えて，圧電バイモルフと回路との連成を考慮する必要がある．本研究では，この逆圧電‐圧電‐回路連成問題に対する新しい有限要素解析手法を提案する．薄い複合材圧電バイモルフを考慮するために，逆圧電解析にはシェル要素，圧電解析にはソリッド要素を用いる．従って，ソリッドとシェルの間における変数変換方法を用いる．回路解析は1自由度で記述する．また，圧電‐回路連成において，電位と電荷の連続性に基づく連成条件式を提案する．連成アルゴリズムは，ブロックガウスザイデル法に基づいている．逆圧電解析において，曲げ剛性および質量に対する材料の複合則を用い，圧電解析において，導体の疑似圧電体評価法を用いる．最後に，本解法によって，RC回路およびシャントダンピングにおける連成現象を正確に解析できることを示す．

DOI： 10.11421/jsces.2020.20200015

その他リンク： https://ci.nii.ac.jp/naid/130007885624

Modeling the cambering of the flapping wings of an insect using rectangular shell finite elements 査読有り

Onishi Minato, Ishihara Daisuke

日本シミュレーション学会英文誌 ( 一般社団法人日本シミュレーション学会 ) 7 ( 1 ) 181 - 188 2020年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Cambering in the flapping wings of insects plays an important role in the aerodynamic performance of their flight. In a previous study, the authors proposed a wing model using shell finite elements to elucidate the mechanism of cambering. However, the analysis of a strongly coupled fluid–structure system using this model would be quite computationally expensive because of the necessity of robust mesh-moving techniques. Therefore, in this study, a new wing model using rectangular shell finite elements is proposed. In the proposed model, the veins and membranes are described as pseudo-elastic materials. The cambering of the proposed model is investigated by comparison with the previous model.

DOI： 10.15748/jasse.7.181

その他リンク： https://ci.nii.ac.jp/naid/130007855464

Performance Evaluation of Numerical Finite Element Coupled Algorithms for Structure-Electric Interaction Analysis of MEMS Piezoelectric Actuator 査読有り

Ramegowda P., Ishihara D., Niho T., Horie T.

International Journal of Computational Methods 16 ( 7 ) 2019年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 World Scientific Publishing Company. This work presents multiphysics numerical analysis of piezoelectric actuators realized using the finite element method (FEM) and their performances to analyze the structure-electric interaction in three-dimensional (3D) piezoelectric continua. Here, we choose the piezoelectric bimorph actuator without the metal shim and with the metal shim as low-frequency problems and a surface acoustic wave device as a high-frequency problem. More attention is given to low-frequency problems because in our application micro air vehicle's wings are actuated by piezoelectric bimorph actuators at low frequency. We employed the Newmark's time integration and the central difference time integration to study the dynamic response of piezoelectric actuators. Monolithic coupling, noniterative partitioned coupling and partitioned iterative coupling schemes are presented. In partitioned iterative coupling schemes, the block Jacobi and the block Gauss-Seidel methods are employed. Resonance characteristics are very important in micro-electro-mechanical system (MEMS) applications. Therefore, using our proposed coupled algorithms, the resonance characteristics of bimorph actuator is analyzed. Comparison of the accuracy and computational efficiency of the proposed numerical finite element coupled algorithms have been carried out for 3D structure-electric interaction problems of a piezoelectric actuator. The numerical results obtained by the proposed algorithms are in good agreement with the theoretical solutions.

DOI： 10.1142/S0219876218501062

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Modeling of cambering in insect’s flapping wings using finite element shell elements 査読有り

Minato Onishi, Daisuke Ishihara

Proceedings of the 38th JSST Annual International Conference on Simulation Technology 271 - 274 4pages 2019年11月

Computational control for strongly coupled Piezoelectric-Structure-Interaction 査読有り

Vinay Shankar, Daisuke Ishihara, Prakasha Chigahalli Ramegowda, Rei Takata, Tomoyoshi Horie

Proceedings of the 38th JSST Annual International Conference on Simulation Technology 275 - 278 4pages 2019年11月

昆虫羽ばたき飛行の特徴的な翼先端軌跡における流体構造連成現象の役割招待有り

石原大輔

昆虫と自然 ( ニュー・サイエンス社 ) 54 ( 8 ) 32 - 34 2019年07月

A novel coupling algorithm for the electric field–structure interaction using a transformation method between solid and shell elements in a thin piezoelectric bimorph plate analysis 査読有り

Ramegowda P., Ishihara D., Niho T., Horie T.

Finite Elements in Analysis and Design 159 33 - 49 2019年07月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Elsevier B.V. Thin piezoelectric bimorph cantilever is increasingly employed throughout the field of actuator and sensor applications in the microelectromechanical system (MEMS). Generally for finite element analysis of piezoelectric bimorph cantilever, three–dimensional (3D)solid element can accurately takes into account a linear or quadratic distribution of electric potential over the thickness for various electric configurations of the actuator and sensor applications. As the MEMS structures usually are quite thin and undergo large deformations, shell elements are very well suited for the structural discretization. This paper is focused on the development of a novel coupled algorithm to analyze the electromechanical coupling in a piezoelectric bimorph actuator and sensor using the shell and solid elements to simulate the structural and electric fields, respectively. The electric force induced by the inverse piezoelectric effect is transformed from the solid elements to the shell elements as an equivalent external force and moment, and the resultant displacements are transformed from the shell elements to the solid elements to evaluate the direct piezoelectric effect. Two different approaches were developed to analyze the electric field–structure interaction. In the first approach, for each block Gauss–Seidel (BGS)iteration, multiple full Newton–Raphson (N–R)iterations are executed until the tolerance criteria are satisfied. In the second approach, the BGS and N–R loops are unified into a single loop. A piezoelectric bimorph actuator and sensor were analyzed for various electrical configurations to demonstrate the accuracy of the proposed method.

DOI： 10.1016/j.finel.2019.02.001

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昆虫羽ばたき翼に生じるキャンバー生成のピクセルモデリング

大西南斗, 石原大輔, 二保知也, 堀江知義

第65回理論応用力学講演会・第22回土木学会応用力学シンポジウム講演論文集 331 - 332 2019年06月

Cycles of triply coupled mechanical contact, current, and thermal conduction phenomena during resistance spot welding 査読有り

Horie T., Niho T., Hayashi N., Ishihara D.

Welding in the World 63 ( 3 ) 701 - 713 2019年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019, International Institute of Welding. The characteristics of the cycles of coupled phenomena that occur among elastic-plastic contact deformation, current distribution, heat generation, and thermal conduction during resistance spot welding are examined using coupled finite element analyses. The current density peak that appears at the center of the interface moves outward along the interface to the high-contact resistance region, then the peaks in the current density, contact resistance, Joule heat generation, and temperature migrate outward with the contact edge followed by the melting zone during the welding process. The influence of welding parameters on the cycles of coupled phenomena is also examined. When the weld current is increased, the current density within the contact surface does not increase but enlarges the high-temperature region instead of heating the central part of the interface. When a small electrode force is applied, the nugget formation is initially enhanced not due to the increased contact resistance but rather because of the increase in the current density through the interface with a reduced contact area.

DOI： 10.1007/s40194-018-00699-5

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薄く柔軟な複合材圧電バイモルフのソリッド圧電‐シェル逆圧電分離反復型解法

石原大輔, プラカシャチガハリラメゴウダ, 高田黎, 二保知也, 堀江知義

計算工学講演会論文集 24 E-10-01 (2pages) 2019年05月

3枚重ね抵抗スポット溶接の構造・電流・熱伝導3 連成現象および接合強度におよぼす鋼板材質・板組の影響

二保知也, 金城喜己, 石原大輔, 堀江知義

計算工学講演会論文集 24 E-12-01 (2pages) 2019年05月

A Computational Study on the Fluid-Structure Interaction Mechanism in Insect Flapping Wings 査読有り

Daisuke Ishihara

Proceedings of The International Conference on Computational & Experimental Engineering and Sciences 21 ( 3 ) 66 - 66 2019年05月

構造‐圧電‐回路連成現象に対する有限要素解析手法の提案

高田黎, 石原大輔, Prakasha Chigahalli Ramegowda, 二保知也, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2019 ( 0 ) 2019年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

A piezoelectric bimorph for actuators and sensors is usually connected to a circuit. The piezoelectric bimorph is affected by charge from the circuit in its mechanical behavior, and it also plays a role of a capacitor in the circuit. Therefore, the coupling of the piezoelectric bimorph and circuit as well as the structure - piezoelectric coupling should be taken into account in the design process of the actuators and sensors using the piezoelectric bimorph. Here, the novel finite element analysis method is proposed for this structure – piezoelectric – circuit coupled problem. Structural and piezoelectric analyses are performed using the finite element method with the shell and solid elements, respectively. Circuit analysis is a single degree of freedom. The coupled equations for the piezoelectric – circuit coupling is proposed from the continuous conditions for the electric potential and charge. The coupled algorithm is based on the block Gauss-Seidel method and a novel transformation method between the solid and shell variables. In the structural analysis, the rule of mixtures about the bending rigidity and the mass is used. In the piezoelectric analysis, the pseudo-piezoelectric evaluation method is used.

DOI： 10.1299/jsmecmd.2019.32.276

その他リンク： https://ci.nii.ac.jp/naid/130007817403

Pseudoelastic mesh–moving using a general scenario of the selective mesh stiffening 招待有り査読有り

Ishihara Daisuke, Goto Atsushi, Onishi Minato, Niho Tomoya, Horie Tomoyoshi

日本シミュレーション学会英文誌 ( 一般社団法人日本シミュレーション学会 ) 6 ( 1 ) 67 - 74 2019年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

The selective mesh stiffening in this study changes the stiffness of the element based on both the element area and shape. It includes the stiffening in the previous studies as a specific case, and leads to a general scenario in the pseudoelastic mesh–moving. This scenario gives better mesh quality in the mesh-moving of a rectangular domain with a structure consisting of a square and a fin undergoes large rotations. This is because the shear deformation of the element is adaptively considered.

DOI： 10.15748/jasse.6.67

その他リンク： https://ci.nii.ac.jp/naid/130007611945

抵抗スポット溶接の接触変形・電流・熱伝導3連成解析における変形効果の重要性

二保知也, 易新宇, 石原大輔, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2019 ( 0 ) 2019年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Resistance spot welding is widely used in manufacturing industries such as automotive industry. In this paper, we propose electric current analysis and thermal conduction analysis with deformation effect for resistance spot welding analysis. Effect of deformation on bonding strength and triply coupled effect for contact deformation, electric current and thermal conduction are discussed.

DOI： 10.1299/jsmecmd.2019.32.227

その他リンク： https://ci.nii.ac.jp/naid/130007817379

Partitioned method of insect flapping flight for maneuvering analysis 査読有り

Onishi M., Ishihara D.

CMES - Computer Modeling in Engineering and Sciences 121 ( 1 ) 145 - 175 2019年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Tech Science Press. All rights reserved. This study proposed a partitioned method to analyze maneuvering of insects during flapping flight. This method decomposed the insect flapping flight into wing and body subsystems and then coupled them via boundary conditions imposed on the wing’s base using one-way coupling. In the wing subsystem, the strong coupling of the flexible wings and surrounding fluid was accurately analyzed using the finite element method to obtain the thrust forces acting on the insect’s body. The resulting thrust forces were passed from the wing subsystem to the body subsystem, and then rigid body motion was analyzed in the body subsystem. The rolling, yawing, and pitching motions were simulated using the proposed method as follows: In the rolling simulation, the difference of the stroke angle between the right and left wings caused a roll torque. In the yawing simulation, the initial feathering angle in the right wing only caused a yaw torque. In the pitching simulation, the difference between the front- and back-stroke angles in both the right and left wings caused a pitch torque. All three torques generated maneuvering motion comparable with that obtained in actual observations of insect flight. These results demonstrate that the proposed method can adequately simulate the fundamental maneuvers of insect flapping flight. In the present simulations, the maneuvering mechanisms were investigated at the governing equation level, which might be difficult using other approaches. Therefore, the proposed method will contribute to revealing the underlying insect flight mechanisms.

DOI： 10.32604/cmes.2019.06781

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85075053780&origin=inward

A coupled finite element analysis approach combining in-house and general-purpose codes 査読有り

Horie T., Niho T., Ishihara D.

IUTAM Bookseries 35 117 - 129 2019年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© Springer Nature Switzerland AG 2019. Coupled finite element analysis is expected in several fields of research and development, where necessity of coupled analysis of not only two phenomena but also three or more phenomena is increasing. The demand for multiscale and multiphysics analyses is also increasing. A coupled analysis approach that combines an in-house code and a general-purpose commercial finite element analysis code using a message passing interface is very promising for these analyses. To examine the practical usefulness and effectiveness, this approach was applied to the triply coupled and multiscale analyses of a resistance spot welding problem and to the dynamic coupled analysis of an ultra sonic piezoelectric motor. The approach is effective to perform various types of coupled finite element analyses of multiphysics and multiscale problems.

DOI： 10.1007/978-3-030-14883-6_7

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068469486&origin=inward

Solid piezoelectric-shell inverse piezoelectric partitioned analysis method for thin piezoelectric bimorph with conductor layers 査読有り

Takata R., Ishihara D., Ramegowda P., Niho T., Horie T.

Transactions of the Japan Society for Computational Engineering and Science ( 一般社団法人日本計算工学会 ) 2019 ( 0 ) 20190011 - 20190011 2019年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 by the Japan Society for Computational Engineering and Science. Piezoelectric bimorph for actuators and sensors is usually thin and includes conductor layers such as the electrode and the shim plate. Therefore, this study deals with the coupled piezoelectric and inverse-piezoelectric analysis of thin piezoelectric bimorph with the conductor layers. Solid elements can describe the various types of distributions of electric potential along the thickness, while shell elements are more appropriate to analyze the thin structures. Therefore, instead of using piezoelectric solid elements or piezoelectric shell elements for both the piezoelectric and inverse-piezoelectric analyses, the solid and shell elements are used to simulate the electrical and structural fields, respectively. The coupled algorithm is based on the block Gauss-Seidel method and the transformation method between the solid and shell variables. In the structural analysis, the rule of mixtures for the bending rigidity and the mass is used. A pseudo-piezoelectric evaluation method for the conductor is proposed in order to use the existing programs for the piezoelectric and inverse-piezoelectric analyses without any modification. Finally, it is demonstrated that the proposed method shows very accurate potential distributions in the actuator and sensor modes of the thin piezoelectric bimorph with the conductor layers.

DOI： 10.11421/jsces.2019.20190011

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昆虫羽ばたき翼に生じるキャンバー生成のピクセルモデリング

大西南斗, 石原大輔, 二保知也, 堀江知義

理論応用力学講演会講演論文集 ( 日本学術会議「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」 ) 65 ( 0 ) 2019年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

昆虫羽ばたき翼におけるキャンバーは，空力性能の向上に重要な役割を果たす．ゆえにその生成メカニズムを解明する事は，昆虫はばたき飛行を理解するために重要である．昆虫はばたき翼のキャンバー生成における翅脈の力学的役割を解明するために，はりとシェルの有限要素を用いた形状簡略化モデルが提案されている．このモデルでは，必然的に不均一な要素分割を用いているため，流体構造連成解析の場合，ロバストなメッシュ制御方法が必要となり，計算コストがかなり高くなることが予想される．そこで本研究では，メッシュ制御を簡易化できるように，均一な要素分割を用いるピクセルモデルを提案する．本モデルでは，メッシュを均一なシェル要素により構成し，その剛性の違いにより，翅脈と翼膜の役割りを与える．先行研究のモデルとの比較を通じて，提案モデルの基本的妥当性について検討する．

DOI： 10.11345/japannctam.65.0_331

その他リンク： https://ci.nii.ac.jp/naid/130008100946

Finite element modeling of flexible piezoelectric energy harvester operating in air

RAMEGOWDA Prakasha Chigahalli, ISHIHARA Daisuke, TAKATA Rei, NIHO Tomoya, HORIE Tomoyoshi

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2019 ( 0 ) 2019年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Piezoelectric energy harvesting from the mechanical vibrations has attracted considerable research interest in the last decade. This work presents a finite element modeling of forced vibration of flexible piezoelectric devices (FPED). The successful design of the FPED depends on the identification of the optimal geometry, material configurations, and loading conditions to achieve maximum power efficiency at a specific band of excitation frequencies. A piezoelectric energy harvesting (PEH) process from the mechanical vibration takes the form of two-way coupling between piezoelectric and inverse piezoelectric effect, while the piezoelectric energy harvesting from the ocean waves takes the form of three-way coupling between fluid, piezoelectric, and inverse piezoelectric effects. There are some experimental and theoretical studies about piezoelectric energy harvesting from the mechanical vibrations as-well as ocean waves in literature. Meantime, performing design optimization via experimental studies is very expensive. An accurate FE modeling of the coupling effects between the fluid, piezoelectric, and inverse piezoelectric effect will reduce the cost-effective design optimization and increase the energy efficiency of the PEH. In the present study, the FE analysis of FEPD is presented. The result obtained with the FE model is compared with the experimental model reported in the literature.

DOI： 10.1299/jsmecmd.2019.32.279

その他リンク： https://ci.nii.ac.jp/naid/130007817401

Role of fluid-structure interaction in generating the characteristic tip path of a flapping flexible wing 査読有り

Ishihara D.

Physical Review E 98 ( 3 ) 2018年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 American Physical Society. This study shows that characteristic modes, such as the figure-eight mode, can be created in the path of the wing tip, which is caused by the fluid-structure interaction, using a flapping model wing with two lumped flexibilities describing the elevation motion as well as the pitching motion. A direct numerical simulation based on the three-dimensional finite element method for fluid-structure interaction (FSI) analyzes the behaviors of the model wing, the surrounding air, and their interaction, where the dynamic similarity law for the FSI is used to incorporate actual insect data, and the parallel computation algorithm is used to perform the systematic parametric study. Characteristic modes, such as the figure-eight mode, are observed in the path of the wing tip from the elevation motion of the simulated wing. This motion is considered as the forced vibration caused by the interaction with the surrounding fluid excited by the flapping of the wing. Therefore, this motion can be modulated by the flexibility to change the natural frequency, which can be controlled by the muscles at the base of the wing in the actual insect. The present simulation shows that the selection between these modes in the path of the wing tip depends on the ratio between the natural frequency of the elevation motion and the flapping frequency. In the case of the figure eight, the upward elevation motion of the wing acts on the leading-edge vortex (LEV) so as to keep its momentum upon stroke reversal. Therefore, this LEV can remain in the wake of the wing after stroke reversal and enhance the next LEV. Because of this effect, the lift increases significantly as the mode of the wing tip path shifts to the figure-eight mode. This understanding will contribute to a developed field of bioinspired micro air vehicles; i.e., it will reduce the complexity of electromechanical devices that prescribe entire motions of their wings.

DOI： 10.1103/PhysRevE.98.032411

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A partition model for the computer simulation of insect flight maneuvers 査読有り

Minato Onishi, Daisuke Ishihara, Horie Tomoyoshi

Proceedings of the 37th JSST Annual International Conference on Simulation Technology 24 - 27 4pages 2018年09月

General scenario of the selective mesh stiffening in the pseudoelastic mesh-moving 査読有り

Daisuke Ishihara, Atsushi Goto, Minato Onishi, Tomoya Niho, Horie Tomoyoshi

Proceedings of the 37th JSST Annual International Conference on Simulation Technology 20 - 23 4pages 2018年09月

Coupled Finite Element Analysis Model of Structural and Electrical Coupled Analysis for Electrical Contact Resistance

Tomoya Niho, Hiroyuki Kuramae, Daisuke Ishihara, Tomoyoshi Horie

Proceedings of the 13th World Congress in Computational Mechanics 2018年07月

昆虫羽ばたき飛行の操縦性に関する分離型解法の検討

大西南斗, 石原大輔, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2018 ( 0 ) 2018年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Insects have developed their high-performance maneuverability using flapping flight in the process of their evolution. In this study, a partitioned method based on our partition model for their flapping flight, which consists of the subsystems of the wings, the body and the control, is proposed to analyze their maneuverability. Here, the proposed method is applied for a maneuver, which is assumed as the perturbation from the static hovering state. In this case, a specific analysis procedure reduced from the proposed method is the one way coupling from the wing to body subsystems, i.e. the insect flapping wings are analyzed using a finite element method for the fluid-structure interaction, the resulted thrust force acts on the insect's body, and its motion is calculated using the equation of motion of a rigid body. The fundamental performance of the proposed method is demonstrated from the comparison between the present results and the actual observation with respect to the yaw, roll, and pitch as three basic modes of maneuver.

DOI： 10.1299/jsmecmd.2018.31.225

その他リンク： https://ci.nii.ac.jp/naid/130007653641

昆虫規範型微小飛行体用トランスミッションのポリマーマイクロマシニングと駆動試験

浦川晃平, 石原大輔, 高木方勝, 村上直, 上尾純平, 熊谷武尊, 堀江知義

年次大会 ( 一般社団法人日本機械学会 ) 2018 ( 0 ) 2018年01月

構造シェル要素と電界ソリッド要素を用いた複合材圧電バイモルフの分離反復型解法

高田黎, 石原大輔, Chigahalli Ramegowda Prakasha, 二保知也, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2018 ( 0 ) 2018年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

In general, piezoelectric bimorph for actuators and sensors is thin and includes electrodes and shim plates. Therefore, this study deals with the thin composite piezoelectric bimorph. Solid elements can describe the various type of distributions of electric potential over the thickness. However, shell elements are more appropriate for the thin structural analysis. Therefore, instead of using piezoelectric solid elements or piezoelectric shell elements, solid elements and shell elements are used to simulate the electrical field and the structural field, respectively. The coupled algorithm is based on the block Gauss-Seidel method and a novel transformation method between the solid and shell variables. In the structural analysis, the rule of mixtures about the bending rigidity and the mass is used. In the electrical analysis, the single piezoelectric solver is used to obtain the potential distribution in the composite piezoelectric bimorph using a pseudo-piezoelectric treatment for the conductor. Finally, this study illustrates the very accurate potential distributions in the actuator and sensor modes of the thin composite piezoelectric bimorph.

DOI： 10.1299/jsmecmd.2018.31.236

その他リンク： https://ci.nii.ac.jp/naid/130007653661

A shape simplification modeling of the cambering in insect’s flapping wings using beam and shell 査読有り

Ishihara D., Yokota J., Onishi M., Niho T., Horie T.

Transactions of the Japan Society for Computational Engineering and Science 2018 2018年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, a shape simplification modeling of insect flapping wings is proposed in order to reveal the mechanical roles of the veins in their cambering, since it seems to be unclear how the elastic deformation of insect wings caused by the aerodynamic force results in their camber. In the proposed modeling, the veins are divided into the areas according to their functions, and the macroscopic constitutive relationship in each area is described using the corresponding beam. Furthermore, the wing membrane supported by the veins is described using a rectangular shell. The aerodynamic pressure dominant in the cambering is considered in the static deformation of the model wing. The finite element analysis taking into account the geometric nonlinearity is applied to the proposed model with the setup consistent with the actual insect. As the result, the mechanical roles of the veins in the cambering of insect flapping wings are revealed.

DOI： 10.11421/jsces.2018.20180018

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接触電気抵抗の大規模ミクロスケール接触変形・電流連成有限要素解析

二保知也, 倉前宏行, 八塚僚介, 堀江知義, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2018 ( 0 ) 2018年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Electrical contact resistance plays important role in melting and bonding of steel sheets interface for resistance spot welding. Although many researchers have proposed theoretical models of electrical contact resistance, microscale structural and electrical coupled finite element analysis is required to evaluate electrical contact resistance because its characteristics depend on the real contact surface, elasto-plastic large deformation contact behavior, electric current and temperature. In this study, we discuss a microscale structural and electrical coupled finite element analysis for the electrical contact resistance. In this analysis, the structural analysis with elasto-plastic, large deformation and contact effect is performed using measured surface based finite element analysis model and temperature dependent material properties. Deformed shape obtained by the structural analysis is used for the electrical analysis considering temperature dependent electrical resistivity. The electrical contact resistance analyses are performed to discuss the SS–RVE (Statistically Similar Representative Volume Element) size and computational cost, and to confirm the validity of the proposed analysis method. The dependency of the electrical contact resistance on the contact pressure and the temperature are compared with those of Babu's model and experimental results from the viewpoint of these path dependencies.

DOI： 10.1299/jsmecmd.2018.31.257

その他リンク： https://ci.nii.ac.jp/naid/130007653677

2.5次元構造を有する昆虫規範型微小飛行体の試作

高木方勝, 石原大輔, 大平直人, 村上直, 堀江知義

バイオエンジニアリング講演会講演論文集 ( 一般社団法人日本機械学会 ) 2018 ( 0 ) 2018年01月

Microfabrication of hybrid structure composed of rigid silicon and flexible PI membranes 査読有り

Murakami S., Ishihara D., Araki M., Ohira N., Ito T., Horie T.

Micro and Nano Letters 12 ( 11 ) 913 - 915 2017年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© The Institution of Engineering and Technology 2017. The authors have designed and microfabricated millimetre-scale wing-shaped hybrid microstructures composed of rigid structures of single crystal silicon (SCS) substrates and flexible polyimide (PI) membranes. The wing-shaped microstructures mimicking insect flapping flight have been newly designed using a fluid-structure interaction analysis, and the hybrid microstructures based on the design method have been successfully microfabricated using a simple process flow with SCS substrates coated with PI membranes. Shape of the SCS parts in the hybrid microstructures have been successfully fabricated using deep reactive ion etching of the SCS substrate with small etching rate, and the wing plates of PI membranes have been prepared with the photolithography and the curing processes. The flexibility of the PI membranes of the fabricated hybrid microstructures was also confirmed using the bending test of the PI membranes.

DOI： 10.1049/mnl.2017.0428

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Microfabrication of hybrid structure composed of rigid silicon and flexible polyimide membranes 査読有り

Murakami S., Ishihara D., Araki M., Horie T., Ohira N., Ito T.

2017 IEEE 12th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2017 840 - 843 2017年08月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2017 IEEE. We have designed and microfabricated millimeter-scale wing-shaped hybrid microstructures composed of rigid structures of single crystal silicon (SCS) and flexible polyimide (PI) membranes. The wing-shaped microstructures mimicking insect flapping flight have been designed using a fluid-structure interaction analysis, and have been microfabricated using microfabrication technologies with the SCS substrates coated with photosensitive polyimide membranes. The shape of the SCS parts of the hybrid microstructures have been fabricated using deep reactive ion etching (D-RIE) process. The flexible parts of PI membranes have been prepared using photolithography and the subsequent curing process of the micro-patterned photosensitive PI thin film. The wing-shaped hybrid microstructures fabricated have been observed, and the flexibility of the PI membrane part of the hybrid microstructures was also confirmed using the bending test of the PI membrane.

DOI： 10.1109/NEMS.2017.8017145

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Strongly Coupled Finite Element Analysis of Electric-Structure-Fluid Interaction in MEMS

Prakasha Chigahalli Ramegowda, Daisuke Ishihara, Tomoya Niho, Tomoyoshi Horie

第64回理論応用力学講演会論文集 No.OS8-02-02, 2pages 2017年08月

Design of micro flexible wing mimicking insect flapping flight using fluid-structure interaction analysis 招待有り

Daisuke Ishihara, Naoto Ohira, Masakatsu Takagi, Sunao Murakami, Tomoyoshi Horie

Proceedings of the JSME-KSME Joint Symposium on Computational Mechanics & CAE 2017 111 - 112 2017年05月

表面マイクロマシニングに基づく昆虫規範型マイクロ飛行体の試作

高木方勝，大平直人，石原大輔，村上直，堀江知義

電磁力関連のダイナミクスシンポジウム論文集 13 - 14 2017年05月

Passive mechanism of pitch recoil in flapping insect wings 査読有り

Ishihara D., Horie T.

Bioinspiration and Biomimetics 12 ( 1 ) 2017年02月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 IOP Publishing Ltd. The high torsional flexibility of insect wings allows for elastic recoil after the rotation of the wing during stroke reversal. However, the underlying mechanism of this recoil remains unclear because of the dynamic process of transitioning from the wing rotation during stroke reversal to the maintenance of a high angle of attack during the middle of each half-stroke, when the inertial, elastic, and aerodynamic effects all have a significant impact. Therefore, the interaction between the flapping wing and the surrounding air was directly simulated by simultaneously solving the incompressible Navier-Stokes equations, the equation of motion for an elastic body, and the fluid-structure interface conditions using the three-dimensional finite element method. This direct numerical simulation controlling the aerodynamic effect revealed that the recoil is the residual of the free pitch vibration induced by the flapping acceleration during stroke reversal in the transient response very close to critical damping due to the dynamic pressure resistance of the surrounding air. This understanding will enable the control of the leading-edge vortex and lift generation, the reduction of the work performed by flapping wings, and the interpretation of the underlying necessity for the kinematic characteristics of the flapping motion.

DOI： 10.1088/1748-3190/12/1/016008

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MEMS技術に基づく微小羽ばたき翼の変位変換システムの設計と試作

大平直人, 石原大輔, 村上直, 堀江知義

日本機械学会第29回バイオエンジニアリング講演会論文集 No.16-76 2F23, 2pages 2017年01月

Stability analysis and evaluation of staggered coupled analysis methods for electromagnetic and structural coupled finite element analysis 査読有り

Niho T., Horie T., Uefuji J., Ishihara D.

Computers and Structures 178 129 - 142 2017年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Elsevier LtdThe numerical stability of electromagnetic and structural coupled analysis methods is examined in terms of the spectral radius for various methods combined with a coupled algorithm, time integration methods for structural analysis and eddy current analysis, and coupled effect evaluation methods. The coupled analysis method with the conventional serial staggered algorithm, generalized–α method for structure, backward difference method for eddy current, and coupled effect evaluation using previous time step results is seen to be the most suitable from the viewpoints of stability and computing time. The stability of the conventional parallel staggered algorithm is found to be much improved if the generalized–α method is used for structural analysis.

DOI： 10.1016/j.compstruc.2016.09.003

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Triply coupled effect of elasto–plastic contact deformation, electric current and thermal conduction of steel sheets interfaces for three sheets resistance spot welding 査読有り

Niho T., Horie T., Ikegami K., Ishihara D., Matsunaga K., Shu T.

Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society ( 一般社団法人溶接学会 ) 35 ( 2 ) 63 - 72 2017年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Japan Welding Society. All Rights Reserved. Resistance spot welding of three steel sheets is used in automotive manufacturing. The determination of welding conditions for three steel sheets welding is more difficult than that for two steel sheets welding because in the former case, two interfaces are simultaneously welded. The welding condition to improve the weld strength of thin and thick sheets’ interface is required for thin, thick, and thick sheets welding. In addition, avoiding weld spatter is an important technical concern for the three sheets welding. This paper discusses the triply coupled effects of elasto–plastic large deformation contact, electric current, and thermal conduction for the three sheets welding via triply coupled finite element analyses. The triply coupled effects of thin and thick sheets’ interface and those of thick and thick sheets’ interface are compared to discuss the special characteristics of the triply coupled effects of three sheets welding. The nugget diameter of the thick and thick sheets’ interface is larger than that of the thin and thick sheets’ interface because the electrical contact resistance and the base electrical resistance of high-strength steels are higher than those of general-strength steels. Furthermore, the chain of the coupled effects of electrical resistances, Joule heat generation, temperatures, and electrical resistances is strong. As the effect of welding current on temperature by the coupling effect for the thick and thick sheets’ interface is stronger than that for the thin and thick sheets’ interface, the possibility of spatter increases. Increasing the nugget diameter solely for the thin and thick sheets’ interface using electrode force is difficult because the effect of the electrode force on the nugget diameter is approximately the same for both interfaces. On the contrary, material characteristics can affect the nugget diameter solely for either of the interfaces. The possibility of spatter increases for the welding condition with a sheet gap because the temperature of the contact edge for the sheets’ interface increases.

DOI： 10.2207/qjjws.35.63

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Microscale electrical contact resistance analysis for resistance spot welding 査読有り

Niho T., Kubota K., Aramaki H., Kuramae H., Ishihara D., Horie T.

Proceedings of the 7th International Conference on Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2017 2017-January 1152 - 1158 2017年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2017 International Center for Numerical Methods in Engineering. All rights reserved. Electrical contact resistance is an important parameter for resistance spot welding. In this study, a microscale electrical contact resistance analysis method is proposed for resistance spot welding. The microscale electrical contact resistance analysis method is combination of an elasto–plastic large deformation contact analysis and an electric current analysis. The electric current analysis is performed for deformed shape of asperity. The tendency of the electrical contact resistance on contact pressure and temperature for the electrical contact resistance analysis agrees with that for Babu’s electrical contact resistance model. A multiscale coupled analysis method is also proposed for resistance spot welding. The multiscale analysis consists of macroscale elasto–plastic large deformation contact, electric current and thermal conduction triply coupled analysis and microscale electrical contact resistance analysis. It is confirmed that the resistance spot welding analysis without measurement of electrical contact resistance can be performed by using the microscale electrical contact resistance analysis.

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昆虫規範型MEMS翼に対する流体構造連成デザインアプローチ

石原大輔, 荒木政輝, 大平直人, 村上直, 堀江知義

理論応用力学講演会講演論文集 ( 日本学術会議「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」 ) 64 ( 0 ) OS8 - 02-01 2017年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

In this study, a FSI design approach of an insect–inspired MEMS wing is proposed. Similar to actual insects, the proposed design actively uses the FSI to create the passive wing motion. Each design solution has a so-called 2.5–D structure for the MEMS technology. The 3–D unsteady monolithic FSI equation system is solved to find the satisfactory design solutions using a projection method. An area of satisfactory design solutions in a design parameter space is found. Each design solution in this area can generate the thrust sufficient to support the weight of the model insect.

DOI： 10.11345/japannctam.64.0_OS8-02-01

その他リンク： https://ci.nii.ac.jp/naid/130007510260

羽ばたき柔軟翼における先端軌跡の流体構造連成による生成に関する数値的検討

石原大輔, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2017 ( 0 ) 2017年01月

要素品質に基づく ALE メッシュ制御手法の開発

後藤篤史, 石原大輔, 堀江知義, 二保知也

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2017 ( 0 ) 2017年01月

抵抗スポット溶接解析における構造・電流・熱伝導3連成モデルおよび微視接触電気抵抗解析モデルの検討

二保知也, 倉前宏行, 荒牧弘親, 中野陽介, 石原大輔, 堀江知義

理論応用力学講演会講演論文集 ( 日本学術会議「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」 ) 64 ( 0 ) OS8 - 02-04 2017年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Resistance spot welding is widely used in manufacturing industry. Analysis of resistance spot welding is required for examination of welding mechanism and determination of welding parameters such as weld current, electrode force and weld time because welding parameters are obtained empirically. In this paper, effect of structure–electric current–thermal conduction triply coupled model on resistance spot welding analysis results are examined to make analysis more efficient. Statistically similar representative volume element size and resolution of finite element analysis model are also discussed for microscale electrical contact resistance analysis of multiscale resistance spot welding analysis.

DOI： 10.11345/japannctam.64.0_OS8-02-04

その他リンク： https://ci.nii.ac.jp/naid/130007510177

抵抗スポット溶接におよぼす構造・電流・熱伝導 3 連成効果の影響度

二保知也, 中野陽介, 堀江知義, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2017 ( 0 ) 2017年01月

Strongly Coupled Finite Element Analysis of Electric-Structure-Fluid Interaction in MEMS

Ramegowda Prakasha Chigahalli, Ishihara Daisuke, Niho Tomoya, Horie Tomoyoshi

理論応用力学講演会講演論文集 ( 日本学術会議「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」 ) 64 ( 0 ) OS8 - 02-02 2017年01月

記述言語：英語掲載種別：研究論文（その他学術会議資料等）

A strongly coupled multiphysics analysis of the electric-structure-fluid interaction in micro electro mechanical system (MEMS) using the finite element method is presented. The strongly coupled electric-structure interaction is based on the block Gauss-Seidel (BGS) iteration scheme, while the strongly coupled structure-fluid interaction is based on the projection scheme. A novel translation algorithm for the electric force and the structural displacement accurately takes into account the electric-structure interaction in MEMS. Therefore, this algorithm combines these schemes to analyze the strongly coupled electric-structure-fluid interaction in MEMS. The proposed method is applied for a flexible piezoelectric bimorph actuator in a channel to demonstrate its performance.

DOI： 10.11345/japannctam.64.0_OS8-02-02

その他リンク： https://ci.nii.ac.jp/naid/130007510311

Fluid-structure interaction design of insect-like micro flapping wing 査読有り

Ishihara D., Ohira N., Takagi M., Murakami S., Horie T.

Proceedings of the 7th International Conference on Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2017 2017-January 870 - 875 2017年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2017 International Center for Numerical Methods in Engineering. All rights reserved. In this study, a FSI design of an insect-like micro flapping wing is proposed. Similar to actual insects, the proposed design actively uses the FSI to create the passive wing motions. Each design solution has a 2.5-D structure for the MEMS technology. The 3-D unsteady monolithic FSI equation system is solved to find the satisfactory design solutions using a projection method in a parallel computation environment. An area of satisfactory design solutions in a design parameter space or Design Window (DW) is presented. Each design solution in the present DW can generate the thrust sufficient to support the weight of the model insect. Therefore, the insect-like MEMS-based MAVs are possible.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85033477617&origin=inward

A finite element approach for a coupled numerical simulation of fluid-structure-electric interaction in MEMS 査読有り

Ramegowda P., Ishihara D., Niho T., Horie T.

Proceedings of the 7th International Conference on Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2017 2017-January 999 - 1007 2017年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2017 International Center for Numerical Methods in Engineering. All rights reserved. In this analyze, a novel finite element coupled algorithm using numerical methods to analyze the interaction between fluid-structure-electric fileds has been presented for piezoelectric actuators. Piezoelectricity is fundamentally an interaction between structure and electric fields. In this paper, at first we analyze the piezoelectric interaction using 3D solid elements and MITC4 shell elements. Solid elements are used for electric analysis and MITC4 shell elements are used for geometric nonlinear structural analysis. The induced electric forces and moment of forces are translated from 3D solid elements to MITC4 shell elements using a novel translation method, and displacements from MITC4 shell elements are translated to 3D solid elements using shell element displacement interpolation functions. A projection method is employed in order to solve the interaction between MITC4 shell structure and fluid field.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85045305426&origin=inward

MEMS 技術に基づく微小羽ばたき翼の変位変換システムの設計と試作

大平直人, 石原大輔, 村上直, 堀江知義

バイオエンジニアリング講演会講演論文集 ( 一般社団法人日本機械学会 ) 2017 ( 0 ) 2017年01月

A novel coupled algorithm for shell structure-electric field interaction analysis in MEMS piezoelectric actuator 査読有り

Prakasha Chigahalli Ramegowda, Daisuke Ishihara, Tomoya Niho, Tomoyoshi Horie

Proceedings of The 35th JSST Annual Conference International Conference on Simulation Technology 2016 332 - 339 2016年10月

Numerical instability of staggered electromagnetic and structural coupled analysis using time integration method with numerical damping 査読有り

T. Niho, T. Horie, J. Uefuji, D. Ishihara

Proceedings of the International Conference on Computational Methods 3 Paper ID 1962, 8pages 2016年08月

Performance evaluation of finite element coupled algorithms for structure-electric interaction analysis of MEMS actuator

Prakasha Chigahalli Ramegowda, Ishihara Daisuke, Niho Tomoya, Horie Tomoyoshi

Proceedings of the 12th World Congress on Computational Mechanics 2016年07月

Fluid-structure interaction design of micro flexible wing mimicking insect flapping flight

Daisuke Ishihara, Sunao Murakami, Masateru Araki, Tomoyoshi Horie

Proceedings of the 12th World Congress on Computational Mechanics 2016年07月

昆虫翼の受動的ピッチング運動に対する周波数比の影響

石原大輔, 白川博基, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2016 ( 0 ) 2016年01月

非線形有限要素解析による昆虫翼構造力学モデルの提案と検討

横田順, 石原大輔, 堀江知義

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2016 ( 0 ) 2016年01月

抵抗スポット溶接時に生じる構造・電流・熱3連成現象の検討および溶接条件の設定

林尚毅, 堀江知義, 二保知也, 石原大輔

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2016 ( 0 ) 2016年01月

3枚重ね抵抗スポット溶接における大変形弾塑性接触・電流・熱伝導3連成現象の検討

二保知也, 池上恭平, 堀江知義, 石原大輔, 松永賢一, 朱徳林

溶接学会全国大会講演概要 ( 一般社団法人溶接学会 ) 2016 ( 0 ) 12 - 13 2016年01月

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

3枚重ね抵抗スポット溶接では，材質や板厚により接合強度を確保し，かつ，スパッタレスな溶接条件設定が難しいケースが多い．本報では，大変形弾塑性接触・電流・熱伝導3連成解析により3枚重ね抵抗スポット溶接特有の3連成現象および溶接条件が接合強度やスパッタにおよぼす影響を検討する．

DOI： 10.14920/jwstaikai.2016f.0_12

その他リンク： https://ci.nii.ac.jp/naid/130005435757

昆虫模倣翼のMEMSプロセスによる試作とその性能評価

荒木正輝，石原大輔，村上直，堀江知義

第7回マイクロ・ナノ工学シンポジウム第7回マイクロ・ナノ工学シンポジウム講演論文集 0pm1-E-5, 2pages 2015年10月

Hierarchically decomposed finite element analysis of the structure-fluid-electrostatic interaction 招待有り

Daisuke Ishihara, Tomoyoshi Horie, Tomoya Niho

Proceedings of the KSME-JSME Joint Symposium on Computational Mechanics & CAE 2015 15-231 20 - 21 2015年10月

Fluid-structure interaction analysis for the aerodynamic contribution to the passive pitching motion of dipteran flapping wings 招待有り査読有り

Daisuke Ishihara, Tomoyoshi Horie, Tomoya Niho

Proceedings of the 8th Asian-Pacific Conference on Biomechanics 66 - 66 2015年09月

Finite element analysis using a hierarchal decomposition for the interaction of structure, fluid and electrostatic field in mems 査読有り

Ishihara D., Horie T., Niho T., Baba A.

COUPLED PROBLEMS 2015 - Proceedings of the 6th International Conference on Coupled Problems in Science and Engineering 1023 - 1028 2015年04月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this study, a hierarchal decomposition for the interaction of the structure, fluid and electrostatic field or the structure-fluid-electrostatic interaction, which is one of typical phenomena in micro-electro-mechanical system (MEMS), is proposed in order to solve it efficiently. The proposed decomposition partitions the structure-fluid-electrostatic interaction into the fluid-structure interaction (FSI) and the electrostatic field, and, moreover, splits the FSI into the velocity and fluid pressure fields. In this way, the whole interaction system is decomposed into the three fields in a hierarchal way. The proposed decomposition is implemented using a finite element method and is applied to a micro cantilever beam actuated by the electrostatic force in air. It follows from the comparison among the results for the structure-fluid-electrostatic interaction, the FSI and the experiment that the proposed method taking into account the full-interaction can predict the vibration characteristic of the MEMS accurately.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84938693972&origin=inward

Elasto-plastic contact, electric current and thermal conduction triply coupled analysis model for resistance spot welding 査読有り

Niho T., Horie T., Morita Y., Ishihara D., Yamakawa D., Momii S.

Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society ( 一般社団法人溶接学会 ) 33 ( 3 ) 271 - 282 2015年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Interactions between elasto-plastic contact deformation, electric current and heat conduction produces complicated triply coupled effect in the resistant spot welding. Since the coupled effect affects weld strength, the coupled finite element analysis is required to determine welding parameters such as welding current, electrode force, welding time and electrode shape. This paper discusses in detail the elasto-plastic contact, electric current and thermal conduction triply coupled analysis method. The coupled analysis method uses modified electrical contact resistance model, modified thermal contact resistance model and iterative partitioned coupled algorithm suitable for strong coupled problem. The validity of the method are discussed under the different condition such as welding current, electrode force, welding time, material and number of the steel sheets. The analysis result of nugget growth curve agrees very well with experimental result for two sheet welding. The validity is confirmed by not only nugget growth curve but also surface temperature of steel sheet and electrode for three sheet welding with high tension steel. The solution convergence is discussed for the iterative partitioned coupled algorithm and the conventional coupled algorithm. Since the coupled effect is strong for between electric current and thermal conduction, the choice of the coupled algorithm is important for the resistance spot welding analysis. Effect of elasto-plastic contact deformation, change of electric current distribution and thermal conduction on resistance spot welding are discussed from the viewpoint of coupled effect. The coupled model with ability to simulate the chain of coupled effect is required to improve the analysis reliability. The importance of temperature dependency of material property, electrical contact resistance, thermal contact resistance and latent heat effect are also discussed.

DOI： 10.2207/qjjws.33.271

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84983313640&origin=inward

Hierarchal decomposition for the structure-fluid-electrostatic interaction in a microelectromechanical system 査読有り

Ishihara D., Horie T., Niho T., Baba A.

CMES - Computer Modeling in Engineering and Sciences 108 ( 6 ) 429 - 452 2015年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Copyright © 2015 Tech Science Press. In this study, a hierarchal decomposition is proposed to solve the structure- fluid-electrostatic interaction in a microelectromechanical system (MEMS). In the proposed decomposition, the structure-fluid-electrostatic interaction is partitioned into the structure-fluid interaction and the electrostatic field using the iteratively staggered method, and the structure-fluid interaction is split into the structurefluid velocity field and the fluid pressure field using the projection method. The proposed decomposition is applied to a micro cantilever beam actuated by the electrostatic force in air. It follows from the comparisons among the numerical and experimental results that the proposed method can predict the MEMS vibration characteristics accurately.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84990191139&origin=inward

258 昆虫羽ばたき翼の受動的ピッチングに対する流体構造連成解析

石原大輔, 堀江知義, 二保知也

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2015 ( 0 ) _258 - 1_-_258-2_ 2015年01月

30pm1-E-5 昆虫模倣翼のMEMSプロセスによる試作とその性能評価

荒木政輝, 石原大輔, 村上直, 堀江知義

マイクロ・ナノ工学シンポジウム ( 一般社団法人日本機械学会 ) 2015 ( 0 ) _30pm1 - E-5-_30pm1-E-5 2015年01月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

In recent years, Micro Air Vehicles (MAVs) mimicking insects have been developed for the purpose of observation in narrow and disaster areas. Micro Electro Mechanical Systems (MEMS) are typically manufactured using the semiconductor manufacturing technology, and have attracted much attention in various fields. In this study, in order to realize an insect-like MAV, its prototype millimeter wing is developed. The prototype wing is designed based on the mechanics of insect flapping wings and the data of an actual insect. The prototype wing made of a single crystal silicon and a polyimide membrane is fabricated, and its fundamental characteristics are evaluated.

DOI： 10.1299/jsmemnm.2015.7._30pm1-E-5

その他リンク： https://ci.nii.ac.jp/naid/110010046076

OS1-5 Fluid-structure interaction analysis for the aerodynamic contribution to the passive pitching motion of dipteran flapping wings(OS1: Bio-inspired Flight System Biomechanics I) 招待有り査読有り

Ishihara Daisuke, Horie Tomoyoshi, Niho Tomoya

Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics ( 一般社団法人日本機械学会 ) 2015 ( 0 ) 2015年01月

An experimental and three-dimensional computational study on the aerodynamic contribution to the passive pitching motion of flapping wings in hovering flies 査読有り

Ishihara D., Horie T., Niho T.

Bioinspiration and Biomimetics 9 ( 4 ) 2014年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2014 IOP Publishing Ltd.The relative importance of the wing's inertial and aerodynamic forces is the key to revealing how the kinematical characteristics of the passive pitching motion of insect flapping wings are generated, which is still unclear irrespective of its importance in the design of insect-like micro air vehicles. Therefore, we investigate three species of flies in order to reveal this, using a novel fluid-structure interaction analysis that consists of a dynamically scaled experiment and a three-dimensional finite element analysis. In the experiment, the dynamic similarity between the lumped torsional flexibility model as a first approximation of the dipteran wing and the actual insect is measured by the Reynolds number Re, the Strouhal number St, the mass ratio M, and the Cauchy number Ch. In the computation, the three-dimension is important in order to simulate the stable leading edge vortex and lift force in the present Re regime over 254. The drawback of the present experiment is the difficulty in satisfying the condition of M due to the limitation of available solid materials. The novelty of the present analysis is to complement this drawback using the computation. We analyze the following two cases: (a) The equilibrium between the wing's elastic and fluid forces is dynamically similar to that of the actual insect, while the wing's inertial force can be ignored. (b) All forces are dynamically similar to those of the actual insect. From the comparison between the results of cases (a) and (b), we evaluate the contributions of the equilibrium between the aerodynamic and the wing's elastic forces and the wing's inertial force to the passive pitching motion as 80-90% and 10-20%, respectively. It follows from these results that the dipteran passive pitching motion will be based on the equilibrium between the wing's elastic and aerodynamic forces, while it will be enhanced by the wing's inertial force.

DOI： 10.1088/1748-3182/9/4/046009

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84914680180&origin=inward

流体構造連成相似則に基づく昆虫羽ばたき翼の解析

石原大輔,堀江知義,二保知也

日本実験力学会2014年度年次講演会論文集講演論文集 14 7 - 8 2014年08月

MEMS構造要素の振動解析における入力データと連成効果の同定

石原大輔, 堀江知義, 二保知也, 馬場昭好

第19回計算工学講演会論文集 19 D-11-4, 2pages 2014年06月

空気中で静電駆動されるマイクロ片持ちはりにおける連成効果

石原大輔,堀江知義,二保知也,馬場昭好

第26回電磁力関連のダイナミクスシンポジウム講演論文集 28 - 29 2014年05月

昆虫羽ばたき翼の受動的ピッチング動力学における空気力効果の数値的検討査読有り

石原大輔, 堀江知義, 二保知也

日本機械学会論文集 ( 一般社団法人日本機械学会 ) 80 ( 812 ) CM0106 - CM0106 2014年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

This study is concerned with aerodynamic effects in passive pitching dynamics of insect flapping wings, which would be based on the Fluid-Structure Interaction (FSI). Thus, we evaluated them using three-dimensional numerical analyses for the FSI based on the finite element method. In the numerical analyses, the FSI in insect flapping wing is broken down into its constituent components in order to find the aerodynamic effects in the passive pitching dynamics as follows: (a) The dipteran passive pitching dynamics is based on the interaction between the wing's elastic and aerodynamic forces, while it is enhanced by the wing's inertial effect. (b) The air damping leads the mode of wing's natural vibration from underdamping to overdamping so as to form the characteristic pitching motion, where the damped natural vibration of the wing appears so as to enhance the wing rotation.

DOI： 10.1299/transjsme.2014cm0106

その他リンク： https://ci.nii.ac.jp/naid/130003399154

相補完的な計算と相似模型実験を用いた流体構造連成シミュレーション

石原大輔, 堀江知義, 二保知也

理論応用力学講演会講演論文集 ( 日本学術会議「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」 ) 63 ( 0 ) 2014年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

流体と構造が強く連成する現象に対する信頼性の高い解析手法が求められている．相似模型実験は，鍵となる無次元数の増加に伴い，それらの条件を同時に満たすことが難しくなる．一方，計算は，近年，急速に発展しているが，現象の複雑化に伴い，一層，結果の妥当性を検討することが求められる．そこで本研究においては，計算と相似模型実験の相補完による流体構造連成シミュレーションを提案し，具体的な流体構造連成現象として，昆虫羽ばたき飛行を取り上げて，その有効性を検討する．

DOI： 10.11345/japannctam.63.0_83

その他リンク： https://ci.nii.ac.jp/naid/130005478028

流体構造連成相似実験の計算による補完と昆虫飛行解析への適用

石原大輔, 堀江知義, 二保知也

計算力学講演会講演論文集 ( 一般社団法人日本機械学会 ) 2014 ( 0 ) 403 - 404 2014年01月

A projection method for the monolithic interaction system of an incompressible fluid and a structure using a new algebraic splitting 査読有り

Ishihara D., Horie T.

CMES - Computer Modeling in Engineering and Sciences 101 ( 6 ) 421 - 440 2014年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Copyright © 2014 Tech Science Press. In this study, a projection method for the monolithic interaction system of an incompressible fluid and a structure using a new algebraic splitting is proposed. The proposed method splits the monolithic equation system into the equilibrium equations and the pressure Poisson equation (PPE) algebraically using the intermediate velocity in the nonlinear iterations. Since the proposed equilibrium equation satisfies the interface condition, the proposed method is strongly coupled. Moreover, the proposed PPE enforces the incompressibility constraint. Different from previous studies, the proposed algebraic splitting never generates any Schur complement. The proposed method is applied to a channel with a flexible flap, which is one of typical test problems, where its superior computational efficiencies are demonstrated.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84919969728&origin=inward

J0220401 昆虫羽ばたき翼の受動的ピッチング運動における空気減衰の数値的検討([J022-04]生物規範メカニクス・システム:生物の運動、力学及びミメティクスセッション(4))

石原大輔, 堀江知義

年次大会 ( 一般社団法人日本機械学会 ) 2014 ( 0 ) _J0220401 - -_J0220401- 2014年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

This study is concerned with air damping effect in passive pitching motion of insect flapping wing, which will be based on the Fluid-Structure Interaction (FSI). Thus, we evaluated it using three-dimensional numerical analyses for the FSI based on the finite element method. From the numerical analysis, we found that the air damping leads the mode of wing's natural vibration from underdamping to overdamping so as to form the characteristic pitching motion.

DOI： 10.1299/jsmemecj.2014._J0220401-

その他リンク： https://ci.nii.ac.jp/naid/110009943479

Convergence evaluation on a projection method for the interaction of an incompressible fluid and an elastic structure 査読有り

Ishihara D., Horie T.

Transactions of the Japan Society for Computational Engineering and Science ( 一般社団法人日本計算工学会 ) 2013 ( 0 ) 20130017 - 20130017 2013年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, performances of a projection method for the interaction system of an incompressible fluid and a flexible elastic structure are evaluated. The proposed projection method splits the monolithic equation system into the equilibrium equations and the pressure Poisson equation (PPE) using the intermediate velocity in the nonlinear iterative procedure. The monolithic equation system has the drawbacks of the large degrees of freedoms and the ill-condition. The proposed formulation reduces these drawbacks. The performance of the proposed projection method is demonstrated using a channel with a flexible flap, which is one of typical test problems, and a flapping flexible wing in a closed tank with comparable fluid and structural mass densities. It follows from the results for these numerical examples that the proposed projection method is efficient for the cases, where some conventional monolithic and partitioned methods would suffer the numerical difficulties. © 2013 by the Japan Society for Computational Engineering and Science.

DOI： 10.11421/jsces.2013.20130017

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84891934466&origin=inward

A consistent projection method for monolithic fluid-structure interaction systems 査読有り

Daisuke Ishihara, Tomoyoshi Horie

Proceedings of Computational Methods for Coupled Problems in Science and Engineering V (COUPLED PROBLEMS 2013) (CD-ROM) 2013年06月

Finite element analysis using hierarchal decomposition for interaction of structural, fluidic and electrostatic fields in MEMS structural components 査読有り

Ishihara D., Horie T., Niho T., Baba A.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A ( 一般社団法人日本機械学会 ) 79 ( 804 ) 1291 - 1302 2013年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study a finite element analysis using hierarchal decompositions for the interaction of structural, fluidic and electrostatic fields is applied for vibration analyses of a MEMS structural component. The interaction is partitioned into the electrostatic field and the fluid-structure interaction (FSI) using the block Gauss-Seidel method. The FSI is split into the pressure field and the other using a projection method, where the intermediate state variables are used for the splitting without generating computationally expensive Schur complement matrices. The developed finite element analysis is applied for a micro cantilever beam actuated by the step electrostatic force in vacuum and air. It was demonstrated from the comparisons among the numerical and experimental results that the proposed analyses provide the results consistent with the experimental results. It follows from the present results that the numerical analyses taking into account the interaction of the structural, fluidic and electrostatic fields are required for the accurate predictions of the vibration characteristics of the MEMS structural components. © 2013 The Japan Society of Mechanical Engineers.

DOI： 10.1299/kikaia.79.1291

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84885225030&origin=inward

Consistent projection method for fluid-structure interaction 査読有り

Ishihara D., Horie T.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A ( 一般社団法人日本機械学会 ) 79 ( 804 ) 1161 - 1170 2013年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study a consistent projection method for the fluid-structure interaction (FSI) was proposed. The intermediate state variables were used to split the monolithic equation system into the equilibrium equations and the pressure Poisson equation (PPE). The incompressibility constraint is asymptotically satisfied by solving the proposed PPE in the iterative solution procedure under the asymptotic agreement of the intermediate velocity with the velocity. Therefore the proposed method is consistent with the monolithic method. The performance of the present method was demonstrated using a channel, which is one of typical test problems, and a flexible wing flapping in the closed fluid domain with the comparable fluid and structural densities. © 2013 The Japan Society of Mechanical Engineers.

DOI： 10.1299/kikaia.79.1161

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Finite element analysis for interaction problems of structure, fluid and electrostatic field in micro cantilever beams 招待有り査読有り

Daisuke Ishihara, Tomoyoshi Horie, Tomoya Niho, Akiyoshi Baba

Proceedings of KSME-JSME Joint Symposium on CM & CAE 2012 255 - 260 2012年09月

流体構造連成によって生じるハエ目の受動的ピッチング運動の動力学的相似実験による評価（共著）査読有り

石原大輔, 吉田翔太郎, 志村高規, 堀江知義, 二保知也

日本機械学会論文集B編 78 ( 786 ) 300 - 310 2012年02月

MEMSにおける構造‐流体‐静電界連成現象の汎用連成シミュレーション手法の開発招待有り

石原大輔,馬場昭好

財団法人カシオ科学振興財団平成２２年度年報 2 - 80-81 2010年08月

A Three-Dimensional Computational Study on the Fluid-Structure Interaction Cause of Wing Pitch Changes in Insect Flapping Flight 査読有り

Daisuke Ishihara,Tomoyoshi Horie,Tomoya Niho

Proceedings of the 9th World Congress on Computational Mechanics and 4th Asian Pacific Congress on Computational Mechanics 27 - 28 2010年07月

Parallel Monolithic Approach for Shell-Fluid Interaction Analysis of Flapping Flexible Wing 招待有り査読有り

Daisuke Ishihara,Tomoyoshi Horie,Tomoya Niho

Proceedings of 4th Korea-Japan COSEIK-JSCES Workshop on Computational Engineering 26 - 27 2010年05月

A study on the passive pitching and lift generation in crane-fly's flight 査読有り

Ishihara D., Yamashita Y., Horie T., Niho T.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B ( 社団法人日本機械学会 ) 76 ( 764 ) 601 - 607 2010年04月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, we evaluated the lift force generated by the crane-fly's flapping wing with the passive pitching using the dynamically scaled model. Since the wing and the surrounding fluid interact with each other, the dynamic similarity between the model and actual crane-fly flights was measured using not only the Reynolds and Strouhal numbers but also the mass and Cauchy numbers. Although there existed the difference between the mass number due to the constant acceleration of the gravity, but the lift coefficient simulated by our model indicated that the flapping wing with the passive pitching produces the enough lift force to support the crane-fly's weight.

DOI： 10.1299/kikaib.76.764_601

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Finite Element Analysis for Coupled Problems of Structure, Fluid and Electrostatic Field in Micro Cantilever Beam 招待有り査読有り

Daisuke Ishihara,Tomoyoshi Horie,Tomoya Niho,Akiyoshi Baba

2nd International Workshops on Advances in Computational Mechanics 1 - 121 2010年03月

Passive maintenance of high angle of attack and its lift generation during flapping translation in crane fly wing 査読有り

Ishihara D., Yamashita Y., Horie T., Yoshida S., Niho T.

Journal of Experimental Biology 212 ( 23 ) 3882 - 3891 2009年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

We have studied the passive maintenance of high angle of attack and its lift generation during the crane fly's flapping translation using a dynamically scaled model. Since the wing and the surrounding fluid interact with each other, the dynamic similarity between the model flight and actual insect flight was measured using not only the non-dimensional numbers for the fluid (the Reynolds and Strouhal numbers) but also those for the fluid-structure interaction (the mass and Cauchy numbers). A difference was observed between the mass number of the model and that of the actual insect because of the limitation of available solid materials. However, the dynamic similarity during the flapping translation was not much affected by the mass number since the inertial force during the flapping translation is not dominant because of the small acceleration. In our model flight, a high angle of attack of the wing was maintained passively during the flapping translation and the wing generated sufficient lift force to support the insect weight The mechanism of the maintenance is the equilibrium between the elastic reaction force resulting from the wing torsion and the fluid dynamic pressure. Our model wing rotated quickly at the stroke reversal in spite of the reduced inertial effect of the wing mass compared with that of the actual insect This result could be explained by the added mass from the surrounding fluid. Our results suggest that the pitching motion can be passive in the crane fly's flapping flight.

DOI： 10.1242/jeb.030684

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A two-dimensional computational study on the fluid-structure interaction cause of wing pitch changes in dipteran flapping flight 査読有り

Ishihara D., Horie T., Denda M.

Journal of Experimental Biology 212 ( 1 ) 1 - 10 2009年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, the passive pitching due to wing torsional flexibility and its lift generation in dipteran flight were investigated using (a) the non-linear finite element method for the fluid-structure interaction, which analyzes the precise motions of the passive pitching of the wing interacting with the surrounding fluid flow, (b) the fluid-structure interaction similarity law, which characterizes insect flight, (c) the lumped torsional flexibility model as a simplified dipteran wing, and (d) the analytical wing model, which explains the characteristics of the passive pitching motion in the simulation. Given sinusoidal flapping with a frequency below the natural frequency of the wing torsion, the resulting passive pitching in the steady state, under fluid damping, is approximately sinusoidal with the advanced phase shift. We demonstrate that the generated lift can support the weight of some Diptera.

DOI： 10.1242/jeb.020404

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Incremental formulation of pressure based method for fluid-rigid body interaction using intermediate variable and its verification 査読有り

Ishihara D., Matsumoto J.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B 74 ( 12 ) 2419 - 2425 2008年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, an incremental formulation of pressure based method for fluid-rigid body interaction using intermediate variable is presented. The present method is based on the method proposed by Matsumoto and Kawahara in previous studies. In their method, the pressure Poisson equation equivalent to the incompressibility constraint is derived by using the intermediate fluid velocity and the approximation of enough small error between the intermediate fluid velocity and the fluid velocity. In the present method, all terms appear in the coupled equation system are evaluated in the same time instant, and unknown variables are solved incrementally by iterative solution procedure in each time step so as to satisfy the coupled equation system defined in the time instant. The present formulation is required when structural nonlinearity such as large deformation should be considered. The present method is applied for the free vibration of a rigid circular cylinder in a quiescent fluid to verify its performance.

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Development of strongly coupled method for interaction of structure, incompressible viscous fluid and electrostatic field (1st report, rigid body approximation of structure) 査読有り

Ishihara D., Kubota A., Horie T., Niho T., Yoshimura S.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A 74 ( 8 ) 1068 - 1075 2008年08月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, a strongly coupled method for interaction of rigid body, incompressible viscous fluid and electrostatic field is developed. The present method is composed of monolithic and partitioned methods. The former solves structure-fluid interaction and the later solves interaction of electrostatic field and the other fields. The difference between the present method and conventional method is the introduction of the iterative solution procedure in the partitioned method. To demonstrate the fundamental performances of the present method, it is applied to simulate a micro membrane actuated by electrostatic force situated in air. The present result agrees well with the theoretical solution when the displacement of the rigid body is small. We also comfirm that the iterative solution procedure makes the present method to be the strongly coupled method through the numerical example.

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Efficient Parallel Analysis of Shell-fluid Interaction Problem by Using Monolithic Method Based on Consistent Pressure Poisson Equation 招待有り査読有り

Daisuke Ishihara,Shigeo Kanei,Shinobu Yoshimura,Tomoyoshi Horie

Journal of Computational Science and Technology 2 ( 1 ) 185 - 196 2008年06月

Efficient parallel analysis of shell-fluid interaction problem by monolithic method based on consistent pressure poisson equation 査読有り

Ishihara D., Kanei S., Yoshimura S., Horie T.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A 73 ( 1 ) 34 - 41 2007年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, a parallel monolithic method for shell-fluid interaction based on the consistent Pressure Poisson Equation (PFE) is developed and its parallel computational efficiency is demonstrated. The previous and present studies show that iterative solvers without preconditioning work well to solve the PPE, even though the coefficient matrix of the original linearized coupled equations becomes to be ill-conditioned. As a consequence, combining with the iterative solvers without preconditioning parallelized based on the mesh decomposition, the developed method can archive efficient parallel computation. To demonstrate the performances of the developed method, it is applied to simulate the vibration of an elastic plate situated in the wake of a rectangular cylinder and a flapping elastic wing in fluid.

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Development of monolithic method for shell-fluid interaction based on consistent pressure poisson equation 査読有り

Ishihara D., Kanei S., Horie T.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A 72 ( 4 ) 377 - 384 2006年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes an efficient monolithic method for shell-fluid interaction problems based on the fluid pressure Poisson equation (PPE). The PPE is derived so as to be consistent with the coupled equation system for the shell-fluid interaction. In the proposed method, the fluid pressure is derived implicitly so as to satisfy the incompressibility. constraint and all the other unknown variables except those for the shell are derived explicitly. The coefficient matrix of the PPE is well-conditioned even if the structure is very stiff or heavy compared to the fluid, and even if the ill-conditioned submatrix is generated due to the shell elements. These characteristics are successfully utilized to combine the proposed method with the standard conjugate gradient method. To demonstrate fundamental perfermances of the proposed method, it is applied to evaluate the vibration characteristics of a thin elastic cantilever plate in a quiescent fluid.

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Fluid-structure interaction modeling of insect flight (1st report, investigation of automatic wing rotation and lift force generation by two-dimensional numerical analysis) 査読有り

Ishihara D., Horie T.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B 72 ( 6 ) 1410 - 1417 2006年06月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, a novel insect flight model based on fluid-structure interaction is proposed. Incorporating the high compliance of the wing base, which is observed in Diptera, the proposed model can express the automatic control of the wing rotation via fluid-structure interaction and can generate the adequate aerodynamic forces for the insect flight. The fluid-structure interaction is simulated by a monolithic method based on the finite element method. The result given by the proposed model is investigated by comparison with experimental results of the dynamically scaled model of the fruit fly given by Dickinson et al.

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高性能演算サーバーによる並列流体構造連成解析招待有り

石原　大輔

九州大学情報基盤センター広報 6 ( 2 ) 43 - 46 2006年04月

A monolithic approach for interaction of incompressible viscous fluid and an elastic body based on fluid pressure Poisson equation 査読有り

Ishihara D., Yoshimura S.

International Journal for Numerical Methods in Engineering 64 ( 2 ) 167 - 203 2005年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes a new monolithic approach based on the fluid pressure Poisson equation (PPE) to solve an interaction problem of incompressible viscous fluid and an elastic body. The PPE is derived so as to be consistent with the coupled equation system for the fluid-structure interaction (FSI). Based on this approach, we develop two kinds of efficient monolithic methods. In both methods, the fluid pressure is derived implicitly so as to satisfy the incompressibility constraint, and all other unknown variables are derived fully explicitly or partially explicitly. The coefficient matrix of the PPE for the FSI becomes symmetric and positive definite and its condition is insensitive to inhomogeneity of material properties. The arbitrary Lagrangian-Eulerian (ALE) method is employed for the fluid part in order to take into account the deformable fluid-structure interface, To demonstrate fundamental performances of the proposed approach, the developed two monolithic methods are applied to evaluate the added mass and the added damping of a circular cylinder as well as to simulate the vibration of a rectangular cylinder induced by vortex shedding. Copyright © 2005 John Wiley & Sons, Ltd.

DOI： 10.1002/nme.1348

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Monolithic approach for fluid-structure interaction based on consistent pressure poisson equation 査読有り

Ishihara D., Yoshimura S.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B ( 一般社団法人日本機械学会 ) 71 ( 706 ) 1565 - 1572 2005年06月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes a new monolithic approach based on the Pressure Poisson Equation (PPE) I to solve interaction problems of incompressible viscous fluid and an'elastic body. The PPE is derived I so as to be consistent with the coupled equation system for the fluid-structure interaction (FSI). Based on this approach, we develop two efficient monolithic methods. In both methods, the fluid pressure is derived implicitly so as to satisfy the incompressibility constraint and all the other unknown variables are derived fully explicitly or partially explicitly. The coefficient matrix of the PPE for the FSI has characteristics of (a) symmetric and positive definite feature, (b) reduction of degrees of freedoms to be solved, and (c) less dependence of the condition on material properties. The arbitrary Lagrangian-Eulerian method is employed for the fluid to take into account the deformable fluid-structure interface. To demonstrate fundamental performances of the proposed approach, the developed two monolithic methods are applied to simulate the vibration of a rectangular cylinder induced by vortex shedding.

DOI： 10.1299/kikaib.71.1565

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A Monolithic Method for Fluid-shell Interaction Based on Consistent Pressure Poisson Equation 査読有り

Daisuke Ishihara,Tomoyoshi Horie

Proceedings of the First International Conference on Computational Methods for Coupled Problems in Science and Engineering (CD-ROM) 2005年05月

Development of strong coupling method considering non-conforming mesh on fluid-structure interface (1st report, verification of method) 査読有り

Ishihara D., Horie T.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B ( 一般社団法人日本機械学会 ) 71 ( 705 ) 1346 - 1353 2005年05月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes a strong coupling method considering non-conforming mesh on fluid-structure interface. In the present method, a transformation matrix derived from the geometrical relations between non-conforming fluid and structural meshes on fluid-structure interface is directly combined with the formulation of the strong coupling method to satisfy the compatibility and equilibirium conditions on fluid-structure interface. The conjugate gradient method is applied to solve the derived coupled equation system by introducing the consistent pressure Poisson equation. To verify basic characteristics of the proposed method, it is applied for free vibration of a cylinder in quiescent fluid. The added mass and damping coefficients derived by the present method agree well with those by other researchers.

DOI： 10.1299/kikaib.71.1346

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Efficient strong coupling method for fluid-structure interaction based on explicit method for structure and semi-implicit method for fluid 査読有り

Ishihara D.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B ( 一般社団法人日本機械学会 ) 70 ( 700 ) 3098 - 3105 2004年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes an efficient strong coupling method for fluid-structure interaction based on the explicit method for structure and the semi-implicit method for fluid. The solution process of fluid-structure interation system is divided into that of fluid and structure, which is independent to each other except data transfer of the fluid-structure interface. Some existing codes with small modification can be utilized to realize the above two solution processes. Note that the time increment is restricted by the Courant's and diffusive number conditions. The method is applied to solve a loaded cantilever in a flow channel under some conditions. Through the numerical results, characteristics of the method are compared to those of a strong coupling and a weak coupling method.

DOI： 10.1299/kikaib.70.3098

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オブジェクト指向に基づく構造設計用統合化CAEシステムとマイクロマシン構造設計への適用査読有り

吉村忍,石原大輔

日本設計工学会論文集 39 ( 11 ) 584 - 593 2004年11月

マイクロマシンの計算力学シミュレーション査読有り

吉村忍,石原大輔

機械の研究 55 ( 11 ) 1109 - 1118 2003年11月

Parallel multi-steps strong coupling method for interaction of incompressible viscous fluid and an elastic body 査読有り

Ishihara D., Yoshimura S., Yagawa G.

Computational Fluid and Solid Mechanics 2003 1373 - 1376 2003年06月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2003 Elsevier Science Ltd. All rights reserved. This paper describes a parallel strong coupling method for interaction of incompressible viscous fluid and an elastic body. The method is based on a multi-steps strong coupling method proposed by authors, which can employ a conjugate gradient (CG) method to solve the simultaneous equation system. Using the domain decomposition method with the element-by-element approach, the CG algorithm in the method is parallelized. To demonstrate the accuracy and parallel efficiency of the method, it is applied to the problem of vibrating behavior of an impacted cantilever beam in water. The method is implemented on PC-cluster system. The accuracy of the result and parallel efficiency are discussed.

DOI： 10.1016/B978-008044046-0.50336-5

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Design window search using continuous evolutionary algorithm and clustering - Its application to shape design of microelectrostatic actuator 査読有り

Ishihara D., Jeong M., Yoshimura S., Yagawa G.

Computers and Structures 80 ( 31 ) 2469 - 2481 2002年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes a search method for multi-dimensional design window (DW), which is defined as an existing area of satisfactory solutions in a design parameter space. The method consists of the following two steps: (1) direct search for satisfactory design solutions using a continuous evolutionary algorithm (CEA) from a wide area of the design parameter space in a robust manner, and (2) identification of a precise structure of DW by clustering the detected satisfactory solutions with a modified K-means algorithm. The CEA is a kind of genetic algorithms modified to deal with continuous variables. The modified K-means clustering algorithm contains an explicit procedure to determine the optimum number of clusters. The proposed DW search method was implemented to an integrated computational aided engineering system for multi-disciplinary structural design developed by the authors, and then the method was applied to shape design of a microelectrostatic actuator for next generation high-density optical memory. A DW consisting of four clusters, i.e. four sub-DWs was obtained, and the features of the representative design solutions of the four sub-DWs were compared with each other in detail, and a final design solution was determined. © 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0045-7949(02)00293-6

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Multi-step strong coupling method for interaction of incompressible viscous flow and an elastic body 査読有り

Ishihara D., Yoshimura S., Yagawa G.

Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B 68 ( 673 ) 2451 - 2459 2002年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes a multi-step strong coupling method to analyze an equation system of incompressible viscous fluid and an elastic body. The procedure is derived based on the following techniques; (a) sub-structuring, (b) velocity-pressure splitting, and (c) time integration of Newmark's family. Only simultaneous equations with well-defined symmetric matrices are solved in the method. To demonstrate fundamental performance of the method, it is applied to solve an impacted beam in fluid. The result shows good agreement with a previous work.

DOI： 10.1299/kikaib.68.2451

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Multi-steps strong coupling method for interaction of incompressible viscous fluid and an elastic body 査読有り

Daisuke ISHIHARA,Shinobu YOSHIMURA,Genki YAGAWA

Proceedings of Fifth World Congress on Computational Mechanics (http://wccm.tuwien.ac.at/) 2002年07月

Structural design of micro electrostatic acutuator for optical memory using design windows searching method 査読有り

Ishihara D., Jeong M., Yoshimura S., Yagawa G., Kim Y.

2001 International Conference on Modeling and Simulation of Microsystems - MSM 2001 157 - 160 2001年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

For satisfactory design of micromachines, this paper describes a search method for a multi-dimensional design window (DW), which is defined as an area of satisfactory solutions in a feasible design parameter space. The method consists of the following two steps: (1) direct search for satisfactory design solutions using continuous evolutionary algorithm (CEA, a kind of E A), and (2) identification of DWs from the solutions using a modified K-means clustering algorithm. The obtained DWs are expected to give engineers useful information to understand a design problem, and, further, give them new ideas of design. To demonstrate practical performance of the proposed method, it was applied to a shape design of micro electrostatic actuator for optical memory.

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Shape Design of Micro Electrostatic Actuator using Multidimensional Design Windows 査読有り

M.J.Jeong,Y.J.Kim,D.Ishihara,S.Yoshimura,G.Yagawa

Transactions of the KSME 25 ( 11 ) 1796 - 1801 2001年11月

Automated Search for Multidimensional Design Windows Using Continuous Evolutionary Algorithms and Improved K-means Clustering (It's Application to Shape Design of Micro Electrostatic Actuator for Optical Memory) 査読有り

Ishihara D., Jeong M., Yoshimura S., Yagawa G., Komoriya H., Kim Y.

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C 67 ( 654 ) 460 - 468 2001年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper proposes an automated search method for multidimensional design window (DW), which is defined as an area of satisfactory design solutions in a design parameter space, using both continuous evolutionary algorithms (CEA) and improved K-means clustering. This method consists of two phases: (a) CEA-based search for satisfactory design solutions in an ill-structured design space, and (b) clustering-based identification of DWs from the solutions. To demonstrate practical performance of the method, it is applied to an automated structural design of micro electrostatic actuator for optical memory. © 2001, The Japan Society of Mechanical Engineers. All rights reserved.

DOI： 10.1299/kikaic.67.460