Principles of centrifuge modeling in geotechnical engineering have been appreciated since the 1930's and explained by many researchers. Currently more than a hundred geotechnical centrifuges are in operation in various countries. Centrifuge model tests have been used a simulation of soil and structure in realistic scale to reveal unknown behaviors or to verify analytical or numerical estimation, and a direct simulation of the prototype existing somewhere or to be built in a future. In the present article, outline of the similitude of geotechnical centrifuge modeling, and current research projects are described.

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For the jointing method substituting flange joint of the post members of electric transmission towers, a mechanical fitting joint was devised herein. Static tensile loading tests and fatigue tests for the reduced models of the joint were carried out in order to confirm the strengths. Then, the FEM analyses of the models were also carried out. Consequently, the validity of the analytical modeling was confirmed based on the coincidence of the analytical and experimental results. It was certified that the joint has efficient fatigue strength from no fatigue crack occurring for the repeating dynamic loading. Moreover, the load-displacement relationship after fatigue test well agreed with the one of virgin members. Therefore, no decrease of the joint strength was also confirmed.

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In case of the design of the neighbouring construction of tunnel, it is necessary to take into account of the influences of tunnelling on the pre-existing structures. These influences are experimentally investigated using model test apparatus of a pair of tunnels. Stacks of the aluminium rods are used as the model materials of the ground and the stress states within the model tunnel made of photoelastic material (Epoxy resin) are analysed. The change of the pressure applied to the model tunnel is also examined using the numerical results obtained from the boundary element analysis. It is shown that the vertical pressure applied to the pre-existing tunnel is increased by 5% of its initial value and the horizontal value is decreased by 13%.

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The present paper is concerned with the flapping characteristics and the structure dynamics of insect wings. The flapping behavior of some insects is studied using a three-dimensional motion analysis system. The experimentalsystem is composed of two high speed video cameras, motion grabber and a personal computer. The three-dimens ionalrepresentation of insect flapping can be gained by the system. The extrinsic skeleton vibration produced by insect flapping is examined with the optical displacement detector system. The structural properties of some insect wings are also studied by a three-dimensional, optical shape measurement system. Some functional principles underlying insect wing design are revealed by the measurements of surface roughness and flapping analysis.

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For long time, numerous efforts have been made to find a way of performing a comprehensive three-dimensional photoelastic analysis with a model intact, even so the problem is still far from being solved completely because of thedifficulties how to realize the integrated fringe patterns obtained in measurements under continuous rotation of theprineipal birefringence axes. The final goal of this study is aimed at the establishment of new technique for analysis of internal stress distributlon in three-dimensional objects, but in this paper, the authors arrange two glass disks having a different stress state respectively in series and make attempt to separate stress states in each disks using an inverse analysis method. As the result, phase diffbrence and azimuth angle of two disks is successfully separated over the whole field.

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There are many points which depend on a worker's experience in the lathe work. This applies in the contents of the center hole. The destruction of the center hole becomes a big accident. This paper advocates the safetystandard concerning the center hole. It is analyzed about stress in the center hole by the experiment and the calculation.
This study is composed by some analysis methods. A photoelastic method, a method of caustics and a finite element method were used. The two-dimensional model of the center hole was made in the photoelasticity method. The model of the form which is the same as the photoelastic method was used in the two-dimensional finite element method. The model by which real machine parts were faithfully reproduced was analyzed in the three-dimensional finite element method. All results of an analysis were summarized by the three-dimensional finite element method. A final analysis was given by a three-dimensional finite element method about the center hole.

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