著者

河合 浩志 遊佐 泰紀 岡田 裕 塩谷 隆二 山田 知典 吉村 忍

出版者

一般社団法人 日本計算工学会

雑誌

日本計算工学会論文集 (ISSN:13478826)

巻号頁・発行日

vol.2018, pp.20180012, 2018-08-29 (Released:2018-08-29)

参考文献数

27

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本報告では、ハイパフォーマンス・デザインパターンについて紹介する。これはHPC環境のためのデザインパターンであり、主に比較的サイズの小さな抽象データ型をC,C++,Fortranなどのライブラリとして実装するためのものである。ここでは抽象データ型の一つ一つのデータがそれぞれ複数のスカラー変数の組として表現され、また関連する手続き群については関数やサブルーチンではなく、プリプロセッサマクロとして実装される。例として、連続体力学での利用を想定しベクトル、テンソルや小規模行列演算を対象とするAutoMTライブラリをとりあげ、本手法に基づき性能最適化を行い、またそのベンチマーク結果を示す。

著者

荒井 皓一郎 岡田 裕 遊佐 泰紀

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00115, 2018 (Released:2018-07-25)

参考文献数

25

被引用文献数

3

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In this paper, a new formulation of three-dimensional J-integral for the evaluation of elastic-plastic fracture problem is presented. It is known that the J-integral represents the energy release rate per unit crack extension. The J-integral is a path-independent integral and can be computed on arbitrary integral path or domain. This property requires the assumption of proportional loading when an elastic-plastic material is considered. Because of this assumption, J-integral loses path-independent property under a non-proportional loading condition. We present a new formulation of three-dimensional J-integral representing the energy dissipation inside a small but finite domain in the vicinity of crack front. The dissipated energy includes the energy released by crack extension and the deformation energy that dissipates in the process zone. This formulation is the extension of the three-dimensional J-integral using equivalent domain integral method and derived without any assumptions on the deformation history. Therefore, it is possible to evaluate the J-integral for problems subject to any load histories. Finally, the problems of hyperelastic and large deformation cyclic elastic-plastic analysis using finite element method are presented. They show that the proposed method can be applied to non-proportional loading problem.

著者

佐藤 皓明 遊佐 泰紀 岡田 裕

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00300-17-00300, 2017 (Released:2017-10-25)

参考文献数

20

被引用文献数

3

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In this paper, formulations and some computational results of cycle jump method based on the nonlinear finite element method are presented. Problems, involving nonlinear cyclic deformation, such as low cycle fatigue problems can be solved by the proposed cycle jump method. To solve the problems of nonlinear cyclic deformation of structure by the nonlinear finite element method with a cycle-by-cycle approach, a large amount of computational time is generally required. Thus a cycle jump method is presented from a view point of temporal multi-scale analysis. Then, an alternative analytical procedure consisting of three steps is proposed. They are a few cycles of nonlinear analysis in a cycle-by-cycle fashion, computations of jumps of strain history dependent quantities (extrapolations) based on the results of the cycle-by-cycle analysis and a cycle jump for several dozen to several hundred cycles using the results of the extrapolations. The results of cycle jump analyses are presented and their accuracies are critically examined. It was found that the results of several load cycles at the beginning of each cycle-by-cycle analysis step should be excluded from the computations of the extrapolation step.