Transient problem for semi-infinite crack in periodically voided materials

A method, which has been recently established for the modeling of long (semi-infinite) cracks embedded in materials with periodic microstructure, is implemented to determine the initial static and dynamic field in materials in which square voids are distributed in a doubly periodic manner. The method is based on the utilization of the K-field of the homogeneous orthotropic material that effectively represents the voided material far away from the crack. The Mode I field distribution is determined by solving the governing equations and boundary conditions, in conjunction with the discrete Fourier transform. The occurrence of the overshooting phenomenon is investigated for various values of the parent solid material volume fraction and the possibility of a stable crack propagation is determined.