YAMAGUCHI Eiki

写真a

Title

Professor

Laboratory

1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka

Research Fields, Keywords

Steel Bridges, Structural Analysis, Maintenance, Design

Undergraduate Education 【 display / non-display

  • 1981.03   The University of Tokyo   Faculty of Engineering   Graduated   JAPAN

Degree 【 display / non-display

  • Purdue University -  Ph.D.  1987.12

Biography in Kyutech 【 display / non-display

  • 2016.04
    -
    2018.03

    Kyushu Institute of TechnologyExecutive Vice President  

  • 2008.04
    -
    Now

    Kyushu Institute of TechnologyFaculty of Engineering   Department of Civil and Architectural Engineering   Professor  

Biography before Kyutech 【 display / non-display

  • 1992.04
    -
    1994.03

    University of Tokyo   Associate Professor (as old post name)   JAPAN

  • 1990.07
    -
    1992.03

    University of Tokyo   Lecturer   JAPAN

  • 1987.04
    -
    1990.06

    Kyushu University   Research Assistant   JAPAN

Specialized Field (scientific research fund) 【 display / non-display

  • Structural engineering/Earthquake engineering/Maintenance management engineering

 

Publications (Article) 【 display / non-display

  • Effect of rubber insertion on impact behavior of multilayer steel fiber reinforced concrete bulletproof panel

      216   476 - 484   2019.08  [Refereed]

     View Summary

    © 2019 Elsevier Ltd In this study, the effect of para rubber insertion sheet on impact behavior of multilayer bulletproof panel made of steel fiber reinforced concrete was investigated. The objective of inserting rubber sheet into the middle layer was to act as a trapping layer to prevent bullets from ricocheting off the panel. Two test series were carried out: (1)investigation on energy absorption of each materials and (2)investigation on impact behavior of multilayer panel. The results from the 1st test series were used in the design of multilayer panels used in the 2nd series. The target impact energy of the bullet was 607 J. The multilayer panels were designed to have energy level ranging from 450 to 750 J. The panels were subjected impact by 9 mm caliber bullet with velocity of about 398 m/s. Results showed that the panels with impact energy absorption (IEA)level lower than the kinetic energy of the bullet (607 J.)failed by perforation. The panels with IEA level equal to or higher than 607 J. exhibited penetration failure mode with circular spalling at the back surface. There was no bullet ricocheting that occurred beyond this IEA level. At the level of IEA higher than 672 J, the failure mode shifted to penetration without visible damage at the back surface.

    DOI Scopus

  • Thermally induced dynamics of deployable solar panels of nanosatellite

      91 ( 7 ) 1039 - 1050   2019.07  [Refereed]

     View Summary

    © 2019, Emerald Publishing Limited. Purpose: This study aims to predict the types of thermally induced dynamics (TID) that can occur on deployable solar panels of a small form factor satellite, CubeSat which flies in low Earth orbit (LEO). The TID effect on the CubeSat body is examined. Design/methodology/approach: A 3U CubeSat with four short-edge deployable solar panels is considered. Time historic temperature of the solar panels throughout the orbit is obtained using a thermal analysis software. The results are used in numerical simulation to find the structural response of the solar panel. Subsequently, the effect of solar panel motion on pointing the direction of the satellite is examined using inertia relief method. Findings: The thermal snap motion could occur during eclipse transitions due to rapid temperature changes in solar panels’ cross-sections. In the case of asymmetric solar panel configuration, noticeable displacement in the pointing direction can be observed during the eclipse transitions. Research limitations/implications: This work only examines an LEO mission where the solar cells of the solar panels point to the Sun throughout the daylight period and point to the Earth while in shadow. Simplification is made to the CubeSat structure and some parameters in the space environment. Practical implications: The results from this work reveal several practical applications worthy of simplifying the study of TID on satellite appendages. Originality/value: This work presents a computational method that fully uses finite element software to analyze TID phenomenon that can occur in LEO on a CubeSat which has commonly used deployable solar panels structure.

    DOI Scopus

  • Seismic retrofit of steel truss bridge using buckling restrained damper

      9 ( 14 )   2019.07  [Refereed]

     View Summary

    © 2019 by the authors. Buckling Restrained Bracings (BRBs) are widely used to improve the seismic behavior of buildings. They are employed for bridges as well, but their application in this respect is limited. BRBs can also be used as a function of the individual damper rather than the structural component or the bracing, in which case the device may be called a Buckling Restrained Damper (BRD). Yet, such application has not been explored much. There are quite a few bridges designed according to the old design codes in Japan. Their seismic resistance may not be satisfactory for the current seismic design codes. Against this background, the behavior of a steel truss bridge under a large seismic load was investigated by nonlinear dynamic finite element analysis. Some members were indeed found to be damaged in the earthquake. Retrofitting is needed. To this end, the application of BRD was tried in the present study: a parametric study on the seismic behavior of the truss bridge with BRD was conducted by changing the length, the cross-sectional area, the location and the inclination of BRD. The effectiveness of BRD was then discussed based on the numerical results thus obtained. In all the analyses, ABAQUS was used.

    DOI Scopus

  • Comparison of solar radiation torque and power generation of deployable solar panel configurations on nanosatellites

      6 ( 5 )   2019.05  [Refereed]

     View Summary

    © 2019 by the authors. Nanosatellites, like CubeSat, have begun completing advanced missions that require high power that can be obtained using deployable solar panels. However, a larger solar array area facing the Sun increases the solar radiation torque on the satellite. In this study, we investigated solar radiation torque characteristics resulting from the increased area of solar panels on board the CubeSats. Three common deployable solar panel configurations that are commercially available were introduced and their reference missions were established for the purpose of comparison. The software algorithms used to simulate a variety of orbit scenarios are described in detail and some concerns are highlighted based on the results obtained. The solar power generation of the respective configurations is provided. The findings are useful for nanosatellite developers in predicting the characteristics of solar radiation torques and solar power generation that will be encountered when using various deployable solar panels, thus helping with the selection of a suitable configuration for their design.

    DOI Scopus

  • Thermal distortion on deployable solar panels of cubesat in low earth orbit

      165   2107 - 2117   2018.01  [Refereed]

     View Summary

    © 2018 KASHYAP. This study predicts thermal distortion that can occur on deployable solar panels of a CubeSat in low earth orbit during eclipse transition of night-day. A 3U CubeSat with four short edge deployable solar panels that point to the Sun is considered. There are three steps of modeling involved. Firstly, the time historic temperature of the solar panel is characterized. Secondly, the results obtained are used in general stress analysis using a finite element software to obtain deformation of the solar panel. Finally, the effect of solar panel motion on the attitude displacement of the satellite is examined using inertia relief method. Results show that quasi-static deformation appears due to the difference in crosssection temperature of the solar panel. Brief thermal snap disturbances are likely to take place during eclipse transitions as well. As a result, the pointing direction of the CubeSat could be disturbed in the case when the solar panels are in asymmetric configuration.

    Scopus

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