Understanding crack growth behavior in complex materials is critical to material design for damage tolerance. An advancing crack, by virtue of its stress field, modifies the microstructure ahead of it including include changes in dislocation density, interfaces modification, decohesion of interfaces, void nucleation, and phase transformation . Such changes in microstructure can in turn have a reciprocal effect on the advancing crack. The problem is hierarchical in length scale and must be examined at the continuum, mesoscopic and atomic scales.
