大規模破壊力学解析のための応力拡大係数計算手法: 混合モード/複雑形状き裂解析のための四面体要素用仮想き裂閉口積分法（VCCM））

摘要

A virtual crack closure-integral method (VCCM) for quadratic tetrahedral finite element that can evaluate the three-dimensional stress intensity factors under mixed mode loading conditions is presented. Present VCCM formulation can handle arbitrary shaped three-dimensional cracks. In the evaluations of the energy release rates and the stress intensity factors, nodal force and displacement data that are the results of finite element computation are used. Present VCCM is quite simple to implement as a post-processing program for finite element softwares. In this paper, the formulation of present VCCM is described in detail and some numerical results are presented. The numerical results are in good agreement with the analytical solutions. Finally, as a demonstration, a problem of three-dimensionally curved crack is presented.%本論文では，四面体有限要素を用いた混合モードき裂の応力拡大係数計算法について表す．三次元き裂問題において，混合モード問題がしばしば表れる．例えば，一様引張荷重を受ける平板の半楕円表面き裂であっても，き裂面が荷重方向に対して傾きを持てば，き裂前縁で全てのき裂変形モードが混在する混合モードき裂問題である．