FEM solutions for plane stress mode-I and mode-II cracks in strain gradient plasticity

The strain gradient plasticity theory is used to investigate the crack-tip field in a power law hardening material. Numerical solutions are presented for plane-stress mode I and mode II cracks under small scale yielding condi tions. A comparison is made with the existing asymptotic fields. it is foun d that the size of the dominance zone for the near-tip asymptotic field, re cently obtained by Chen et al., is on the order 5% of the intrinsic materia l length i. Remote from the dominance zone, the computed stress field tends to be the classical HRR field. Within the plastic zone only force-stress d ominated solution is found for either mode I or mode II crack.