[in Japanese]

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[in Japanese]

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In this paper, we investigated on crystal structure of complex perovskite-type oxides (A,A')(B,B')03 through first-principles calculation to develop novel biocompatible piezoelectric materials. Firstly, biocompatible elements were applied and there combination was selected to satisfy geometric stable condition. Secondly, insulation properties of piezoelectric materials were estimated from band structure through density functional theory (DFT) calculations. Then, the stable tetragonal structure was evaluated and the non-centrosymmetric crystal structures caused by soft modes were predicted from the phonon properties. Finally, we evaluated piezoelectric properties, and discussed the relationship between piezoelectric effect and mass differences between A and B site elements.

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[in Japanese]

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With the aim of achieving stable operation of circular saws, this study finds the solution for the optimization problem of choosing a set of parameters for tensioning in a rotating circular saw that is subjected to both a local temperature distribution arising from the thermal load caused by the blade-workpiece friction and the in-plane plastic strain introduced by tensioning over multiple annular domain. The solution for in-plane forces is obtained on the basis of plate bending theory, and modal analysis for the out-of-plane behavior affected by the in-plane forces is performed. Numerical calculations are performed to investigate the effects of tensioning on the natural frequencies. The optimization problem to maximize, with respect to the intensity, location, and width of tensioning, the natural frequency of the most critical mode is solved by use of a geneticalgorithm.

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Hearth rolls used in continuous annealing furnace for producing thin steel sheet, generally coated by thermal spraying's applied. The surface coating on the hearth roll needs enough adhesion and wear resistance. In this study we focus on the intensity of the singular stress appearing at the end of the JIS specimen used to investigate thermal shock strength. Then, we discuss the effect of thickness of the coat and the bond coat as well as the effect of material property on the intensity. It is found that with decreasing Y_2O_3 contents of the ceramic coat the intensity decreases.

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Analytical problems according to prosthodontics treatments, for example, artesian deformation of oral mucosa, dynamic analysis of tongue, and so on, require viscoelastic analysis with large deformation. As it stands, Finite element method have limit to solve those problems. Instead of that, SPH (smoothed particle hydrodynamics) method have an ability to solve large deformation problems, but that mainly in cases of elastic analysis. Analyzed examples of viscoelastic analysis by SPH method are very few. So if the viscoelastic analysis of SPH method is established, It may have the potential to apply that in medical, biological, and other related study areas.In this study, as a first step of viscoelastic analysis by SPH method, we implemented SPH-Maxwell model program, and analyzed some cases based on experimental value (Vertex soft: denture liner), and finally deliberated the consistency of calculation.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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In this paper, we introduce a new consistent particle method - "Least Squares Moving Particle Semi-implicit (LSMPS) method",including high order meshfree schemes, time marching algorithm, treatment of boundary conditions, and their application for numerical analysis of incompressible flow with the free surfaces.

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For large-scale granular simulations based on Distinct Element Method (DEM), a simulation code has been developed for GPU supercomputers equipped with GPUs. We propose an effective method for dynamic load balance among the decomposed domain assigned to each GPU. Applying the slice-grid method, we maintain the equal number of particles in the domain. Several techniques for particle counting and data movement between GPUs are implemented. The frequency of the memory de-fragmentation on GPU is examined from the view point of the cost of the data communication between CPU and GPU. A link-list technique of the neighbor particles list is introduced to save the memory drastically. The granular simulation works well with the dynamic load balance and good scalability has been achieved with increase of GPUs. The sand behavior of golf bunker shot is demonstrated with over 130 million particles using 256 GPUs. An agitation simulation using billion particles is also carried out on TSUBAME 2.0 at GSIC, Tokyo Tech.

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[in Japanese]

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[in Japanese]

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This paper describes development of visualization library for the next generation super computer. At this moment, the next generation super computer, which is called as Post-Peta or Exa-scale computer, is not designed clearly. We prospect the Exascale computer and research the possibility of new software which is appropriate for possible hardware configuration and architecture to be present. In this work, we show how to visualize and deal with ultra large scale FE data with very fine resolution from a point of data compression view, and we discuss its capability and possibility for the computer.

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