研究者詳細 - 石原　大輔

論文 - 石原　大輔

分割表示188 件中 101 - 120 件目／全件表示 >>

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

CiNii Article

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

CiNii Article

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

Scopus

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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

CiNii Article

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

Kyutacar

Scopus

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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

Kyutacar

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85030845432&origin=inward

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

Scopus

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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

Scopus

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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

Scopus

CiNii Article

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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.

Scopus

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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

CiNii Article

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

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