Element free galerkin study of steady quasi-static crack growth in plane strain tension in elastic-plastic materials

Employing an extension of the convective mesh technique, an Element Free Galerkin (EEG) based formulation for steady quasi-static crack growth in elastic-plastic materials undergoing small scale yielding is established. In accordance with the steady state condition, a parallel path constitutive law integration scheme is implemented into the formulation and a body force type term is introduced for the contribution of crack tip plasticity. A detailed numerical analysis is performed for steady quasi-static growth of a mode I crack under plane strain conditions in elastic-perfectly plastic materials. The numerical solutions to this problem confirm the existence of an elastic unloading wedge. The computed near-tip stress distributions and the crack opening displacements for this problem provide good agreements with the corresponding asymptotic solutions and demonstrate the validity of the EFG based formulation. A rough estimate of the range of validity of the asymptotic solutions is also made based on the numerical solutions. In addition, the effect of strain hardening on the steady quasi-static crack growth is investigated. Both power hardening and linear hardening models are considered.