論文 - 高野　直樹

Microscopic Simulation Technique for Composite Meterials Using the Homogenization Method Based on Fixed Grid

Takano N., Zako M.

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A （Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A）  61 （ 583 ） 589 - 594 1995年

ISSN  03875008

　概要を見る

Recently, the homogenization method is becoming a matter of interest as a new analysis method of composite materials. This method aims at stricter modeling and more precise simulation for any kind of reinforcement. Discretization of complicated microstructures of such reinforcement, however, becomes the bottleneck in the analysis procedure. Therefore, a new simulation technique based on a fixed grid is proposed in this paper. Fundamental investigation of the accuracy of the homogenization method based on a fixed grid for unidirectional FRP is presented. The obtained elastic constants show good agreement with the solution of the Halpin-Tsai equation. Microscopic stress distribution has also been evaluated well compared with conventional smooth finite-element discretization. © 1995, The Japan Society of Mechanical Engineers. All rights reserved.

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Development of Three-Dimensional Finite Element Method for Composite Materials Based on Damage Mechanics

Zako M., Tsujikami T., Takano N.

Journal of the Society of Materials Science, Japan （Journal of the Society of Materials Science, Japan）  44 （ 502 ） 921 - 926 1995年

ISSN  05145163

　概要を見る

A computer program of the three-dimensional finite element method for composite materials based on damage mechanics has been developed. There are many kinds of fracture pattern in composite materials. Especially, the progression of fracture caused by out-of-plane and shearing deformation is very complex. The effect of these fracture patterns on the mechanical behavior must be considered for the design and analysis of fracture behavior of composites. The consideration of damage mechanics has been introduced into the proposed program in order to treat above mentioned behaviors. A numerical procedure with new concept for the constitutive equation with damaged elements is introduced in this paper. As an example, the mechanical behavior of laminate under three point bending was analyzed by the developed computer program. The computational results concerning the fracture pattern agreed well with the experiments. Consequently, it can be recognized that our proposed program is very useful for structural design and analysis of mechanical behavior for composite structures. © 1995, The Society of Materials Science, Japan. All rights reserved.

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Development of Design Margin Decision System for Advanced Materials Based on Reliability

Zako M., Takano N., Ichikawa M., Hanaki S.

Transactions of the Japan Society of Mechanical Engineers Series A （Transactions of the Japan Society of Mechanical Engineers Series A）  61 （ 589 ） 1909 - 1913 1995年

ISSN  03875008

　概要を見る

The design concept based on reliability is effective for advanced materials, because advanced materials such as fiber-reinforced composites have variable mechanical properties. In addition, as the failure mode in the low cycle fatigue region differs from that in the high cycle fatigue region, it is difficult to predict the fatigue life of advanced materials. So far, we have developed a design margin decision system based on reliability by evaluating fatigue life. In this study, the system is improved for application to advanced materials and a method to divide whole sets of data into the above two regions and to calculate the design margin in each region is presented. From numerical examples for CF/PEEK laminates and epoxy resin, it is revealed that a more reasonable S-N curve and design margin are obtained by the proposed system. © 1995, The Japan Society of Mechanical Engineers. All rights reserved.

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Application of Steering Technique to Structural Analysis by Finite Element Method

高野 直樹

Jsme News （The Japan Society of Mechanical Engineers）  4 （ 2 ） 7-8 1993年

研究論文（学術雑誌）, 単著, 査読有り

Stress singularities at the interface crack and the corner of edge-bonded dissimilar materials

Miyoshi T., Shiratori M., Okuda H., Takano N.

American Society of Mechanical Engineers, EEP （American Society of Mechanical Engineers, EEP）  1   551 - 557 1992年12月

ISSN  0791807665

　概要を見る

From a structural point of view, the electronic devices and/or components can be classified as the multi-layered structures composed of dissimilar materials. Therefore, the stress singularities caused by the mismatch of the elastic constants and the thermal expansion coefficients has to be taken into consideration when carrying out the finite element stress analysis. In this paper, the stress singularities encountered at the corner of the bonded edge and/or the interface crack tip in dissimilar materials are theoretically described. Furthermore, it is demonstrated that the finite element method can properly explain the theoretical stress singularities i.e. the order of the singularity and the stress distributions. The intensity of the singular stress field, which is measured by the stress intensity factor, is also analyzed.

Finite element analysis by transputer

Miyoshi T., Takano N.

American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP （American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP）  177   105 - 110 1989年12月

ISSN  0277027X

　概要を見る

This paper describes a speed up of finite element analysis by a parallel computer using transputer. As a solver suited for parallel computers, skyline method by Cholesky decomposition in inner product form is presented. This algorithm uses row wise Cholesky decomposition and its parallelism can be extracted easily. In the three dimensional structural analysis, concurrent processing of three rows and columns is shown to be effective. Using this solver, elastic-plastic analyses have been carried out and the computational speed by 4 transputers was about 10 to 20 times faster than by EWS. Furthermore, this solver is one of the direct methods, independent of the number of processors or the architecture of parallel computers and a promising speed up by both vector and parallel processing is possible.

Large scale structural analysis by a supercomputer

Miyoshi T., Takano N., Shiratori M.

American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP （American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP）  177   67 - 71 1989年12月

ISSN  0277027X

　概要を見る

The authors have developed finite element codes FEM3D/S and FEM3D/I for three dimensional large scale structural analysis. Their solvers are based upon parallel skyline method and the ICCG method, respectively, and they are specially designed for the high speed and large scale supercomputing. A bench mark test shows that the developed codes are effective among the different kinds of supercomputers. Further, the authors have developed a system integrated with these codes and pre and post processors, which run on an engineering work station. Examples of the three dimensional elastic-plastic analysis show that the developed system is effective for the large scale structural analysis.

LARGE SCALE STRUCTURAL ANALYSIS BY A SUPERCOMPUTER.

Miyoshi T., Yoshida Y., Takano N.

Journal of the Faculty of Engineering, the University of Tokyo, Series A （Journal of the Faculty of Engineering, the University of Tokyo, Series A）   （ 25 ） 22 - 23 1987年12月

ISSN  05637945

　概要を見る

With the prevalent use of supercomputers, the studies on the techniques of these utilization have widely been conducted. In the field of finite element analysis, three dimensional large scale structural analysis by a supercomputer becomes a matter of concern and interest. In this study, the authors have applied the ICCG method, which is one of the iterative solutions, to the three dimensional finite element analysis.

スーパコンピュータによる大規模構造解析（ICCG法による有限要素解析）

高野 直樹

日本機械学会論文集A編 53 （ 492 ） 1607-1613 1987年

研究論文（学術雑誌）, 共著, 査読有り

Large Scale Structural Analysis by a Supercomputer (Application of the ICCG Method to Finite Element Analysis)

Miyoshi T., Takano N., Yoshida Y.

Transactions of the Japan Society of Mechanical Engineers Series A （Transactions of the Japan Society of Mechanical Engineers Series A）  53 （ 492 ） 1607 - 1613 1987年

ISSN  03875008

　概要を見る

Recently, with the rapid progress of computer technology, there is a growing need for large scale non-linear finite element analyses. However, These calculations take a lot of time and have large storage requirements. The authors have applied the ICCG method, which is one of the iterative solutions, to the three dimensional finite element analysis by supercomputer. Using the ICCG method, large problems with over 10 000 nodes have been solved in a short computational time and with good accuracy. © 1987, The Japan Society of Mechanical Engineers. All rights reserved.

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