Crack growth in particle reinforced composites is significantly influenced by the character of the reinforcement particles.To accurately deal with such problems,the extended finite element method (XFEM) was employed and improved.The simulations are accomplished by using a new domain expression of an interaction integral for evaluating stress intensity factors (SIFs),and by adopting the maximum hoop stress criterion for crack-growth direction prediction.Crack deflection/attraction mechanisms and their associated energy release rate variations are investigated.It is shown that the applied numerical method allows a considerable flexibility and can be used in more general situations.The crack-tip shielding and amplifying behaviors are clearly observed.