A new approach based on descriptive Monte-Carlo simulation sampling for non-linear engineering problem, such as crash problems, is presented. The "descriptive" way is known as one of VRTs (Variance Reduction Techniques) in Monte Carlo simulation techniques, and it is aimed to predict mean behavior of a system by less number of sampling points. In this paper, data analysis example connecting to optimization is also presented. Optimization was performed as a multi-objective optimization considering trade-off.

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A method to express the concept of transferred load in structures with plastic deformation has been introduced. These concepts are applied to a passenger car cabin under frontal collision.

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In the process of optimization with a large nonlinear dynamic analysis, a large amount of computational cost is required to obtain the optimal design. A large portion of this cost can be avoided using Response Surface Model (RSM) by approximating the more costly analysis. Therefore, various optimization problems with this cost were applied by this method. But, on the other hand, this method is not enough advantage for a cost of the process of design. Because, this cost is larger than the requirement time for improving design. We guess this time usually is about one week. Therefore our aim is to reduce a computational cost of the process of optimization to obtain the optimal design within one week. We propose a VCM (Variable Complexity Model) approach using both the simple model with RSM and complex model during the optimization procedure. In this paper, we applied our method to the optimization problem with a nonlinear dynamic analysis, and obtained good results.

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The focus of this research is the high speed bending behavior of hat square column in order to make clear the crashworthiness of vehicle components under side impact collusion. In this paper, the effects of dimension of cross section and effect of material strength on the crashworthiness were discussed with result of high speed crash test and FEM simulations. The experimental results showed that the dimension of cross section effected on the deformed shape and the energy absorption. In addition, the results of FEM simulation showed that the dimension of cross section affected the plastic strain distribution and the crashworthiness.

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In this paper, the elastic structural simulation is presented for the pipe bends which are used in the pipe systems of the atomic or chemical plants. The finite element formulation for a toroidal shell element is given. The bending moment and torque are imposed as the compulsive displacements at the pipe end. Numerical examples are presented for the pipe bends with ninety-degrees opening angle subjected to bending and torsion, and longitudinal, circumferential and shearing stresses intecification factors are shown.

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An experimental and theoretical investigation in magnetic bending behavior of two nearby soft ferromagnetic beam plates was conducted. Bending tests were performed in the bore of a superconducting magnet at room temperature. Ferritic stainless steel SUS430 is here used as the cantilever specimen. The experiments show the predicted increase in the strain with increasing magnetic field. The interaction between the two plates considerably increases the strain. The theoretical analysis is based on a classical plate bending theory for magneto-elastic interactions in a soft ferromagnetic material. Numerical calculations are carried out, and the strain is obtained for several values of magnetic field and geometrical parameter. A comparison of the strain is made between theory and experiment, and the agreement is good for the magnetic field considered.

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In order to study the effects of the tube length on the deformation behavior for free bulged electric resistance welded tubes, the finite element analyses changing the ratio of the tube length to its outside diameter from L/D=1 to L/D=8 were performed. Consequently, it is confirmed that those effects depend on the boundary conditions of tube edges. In the condition not loading axially compressive force to the tube edge, the deformation behavior in the central part of the tube is almost equal between L/D=2 and L/D=8. And, the effects of the plastic anisotropy to the reduction of the tube thickness at L/D=4 depend on the boundary conditions as same as at L/D=2.

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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 special 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. It is accomplished by using analytical solutions such as Eshlby's tensor in boundary element based homogenization formulation.

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Heat wave in elastic material generated by an impulsive heating of the free surface is analyzed numerically by the TVD finite difference scheme. The thermal response of Al metal for a thermal shock is examined through behavior of heat wave. In addition, the propagation of heat wave through a contact boundary between two different metals, Al and Ni, is examined. The numerical results suggest that heat wave plays an important role in an initiation of Ni-Al alloying by an electric resistance welding technique.

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