THE PROJECTED RELATION OF THE CONSERVATION INTEGRAL IN MICROCRACK SHIELDING PROBLEMS
微裂纹屏蔽问题中守恒积分投影关系

In this paper, the J integral conservation in adopting the continuum mechanics in the microcrack shielding problems is reexamined. From thetheoretical manipulation as well as the computational experiment, it is proved that there is a redistribution relation of the remote J integral in the microcracking damage region, i.e., the relation of theprojected conservation of the J k vector. In the relation, the J 2 component ignored by Herrmann and Herrmann plays an important role. It is concluded also that the elastic stiffness reduction, and the presence of strain/deformation due to the release of residual stresses are bothenergy dissipating processes which based on an energy balance approach give rise to toughening and thus crack-tip shielding.