エネルギ解放率の新公式とその応用 : 多軸荷重の場合の簡便評価式

金沢大学理工研究域環境デザイン学系This paper first presents a new type of path independent integral expressing the energy release rate for the crack growth in nonlinear matrials. It is path independent even for the non-straight crack and gives the energy release rate without any limiting process; the J-integral is path independent only for the straight crack. It also generalizes the well-known expression derived by Rice,which may be evaluated from the load versus load-point-displacement curves for slightly different crack size. Then,as an application of the new expression,a simplified formula under multiaxial loadings, which may be evaluated only from a single loads-displacements curve,is derived in similar way as Rice et al. developed under uniaxial loadongs. Finally,the difference between the J-integral and the new expression,when they are applied to elastic-plastic materials,is examined in some detail