An alternating iteration method is applied to evaluate the stress
intensity factors of mixed mode crack interacting with stress free
semi-infinite planes subjected to remote uniform tension. Two types of
interacting problems are assessed, namely crack interacted with half plane
and crack interacts in a long strip (crack interacts with two
stress-free-boundaries). Mixed mode interaction can be drawn in this
method with no difficulty. In addition, conventional Gaussian-Legedre
quadrature scheme is employed for the stress field estimation in this
iterating exploitation. Rapid convergent rates and good correlations with
available published data are achieved in this study. As mixed mode crack
approaches a stress-free-boundary, mode I increases and the mode II stress
intensity factors may reallocate its maximum value to a lower angle from its
original extreme value of 45

aligned angle. Nevertheless, too close
proximity of crack and the stress-free-boundary may jeopardize the
numerical convergence in the alternating iteration due to the inadequacy of
conventional integration scheme in dealing with two approaching stress
singularities.