In this paper, a approximate technique for dynamically simulating the swimming motion is proposed. In this technique, the formulation of the dynamic equations subject to the propulsion force under water is presented. As a simple numerical example for the motion of the whole human body, the backstroke was simulated. The results of the simulation show that the technique can improve the reality of motion although this is still the first step for the simulation of swimming of the human body.

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Skew phenomena of a flat belt running between misaligned cylindrical rollers are numerically investigated by using FEM software (MARC/Mentat). Characteristics of skew phenomena and effects of main parameters (misaligned angle, friction force, Young's modulus, width and length of belt, diameter of rollers, and so on) have been clarified in the previous paper. In MARC software, a modified Coulomb friction model is used, in which the modified friction force changes smoothly against relative velocity by using a factor C. In this study, effects of the factor C on simulation results of the belt skew are discussed. The results show that the simulated results for small value of C have a good accordance with experimental results comparing with those for large value of C (C=1,default).

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This paper presents an efficient calculation method for optimal design of topological structuring shape with minimum weight and high strength, using finite element method (FEM). This topological design is based on optimality criteria with the constraint condition of a porous elastic body, without a homogenization method. Two asteroid types of cell structuring element used in the FEM cause the element shape to deform under low shearing force, in order to obtain the topological shapes with high accuracy and short CPU time. The validity of this method is confirmed from the optimum topological shapes of two-dimensional finite element models.

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A homogenization method for solid having periodic microstructure is developed for two phase composite material, in which second phase particles densely distribute in matrix material. When the distribution of second particles are random, many particles need to be included in a unit cell to calculate the effective mechanical behavior of the solid. However, use of popular displacement finite element method for such problems is, in general, prohibitive, because spatial discrtization which is required for such problems, would be too extensive. In this paper, a homogenization technique which can fully account for mechanical interactions between individual particles and can be used for the analysis of unit cell having many (hundreds of) second phase particles, is presented and applied to the problems of stress induced transformation plasticity.

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Stress interactions occurring between dispersed dispersed inclusions in the composite material cause nonuniform as well as intense stress distributions in the matrix phase. The meso-local phenomena of nonlinear material characteristics caused by the local interaction will further cause with each other a secondary interaction between the multiple nonlinear material behaviors. In this paper, the damage and the phase transformation phenomena interfering with each other are investigated by FEM meso-mechanics analysis, and also the development of the macro constitutive modeling incorporating the both effects is attemped.

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