Collinear Crack Problem in a Graded Medium

摘要

The collinear crack problem in an inhomogeneous orthotropic medium is considered under Mode I plane strain or plane stress loading conditions. It is shown that by introducing certain averaged orthotropy parameters, aside from a scaling parameter the results become only weakly dependent on the orthotropy constants. The main results of the study consist of the stress intensity factors at various crack tips as influenced by the material inhomogeneity parameter and by the relative size and position of the secondary cracks with respect to the dominant crack. Also considered is the crack/contact problem for the graded medium subjected to remote tension and bending through fixed grips. It is shown that the crack surface contact on the compression side of the loading has a magnifying effect on the stress intensity factor on the tension side.