EFFECTS OF ANISOTROPIC HARDENING ON CRACK-PROPAGATION IN POROUS-DUCTILE MATERIALS

Slow, stable, rectilinear crack propagation is investigated for porous , elastoplastic solids displaying combined isotropic and kinematic har dening. The Gurson model with constant porosity, and therefore the ass ociated flow rule, is used as the constitutive description. An asympto tic analysis of crack-tip fields is performed under Mode I, steady-sta te, small-strain, plane stress and plane strain conditions. A continuo us distribution of asymptotic near-tip fields is found. However, the p ossibility of the appearance of stress jumps in the asymptotic fields is analysed in detail. The results show many interesting features, whi ch are related to the presence of both porosity and Bauschinger effect . Copyright (C) 1996 Elsevier Science Ltd