Antiplane shear crack growth under quasistatic loading in a damaging material

Antiplane shear crack growth is examined numerically in a precracked rectangular specimen subjected to quasi-static antisymmetric loading, by cohesive layer modeling. Material in the cohesive layer ahead of the crack tip is modeled to be linear elastic-softening with a, damaging locus while bulk material of the specimen is assumed to be linear elastic; The evolution of physical and fictitious crack tips is obtained from solutions to the boundary value problem formulated. Critical values of the J-integral and crack opening displacement (COD) for onset of either stable or unstable crack growth are examined, and shown to be dependent upon initial crack length, loading distribution as well as material properties. It is also shown that a unique relationship between a critical value of J integral and a critical COD cannot be obtained in general. The iterative method of Successive-Over-Relaxation (SOR) is applied in the present work. (C) 1998 Elsevier Science Ltd. All rights reserved.