Edge-cracks in single crystals under monotonic and cyclic loads

Basic solutions are obtained for edge-cracks lying along the primary slip p lane in a single crystal. The study is motivated by Stage I fatigue crack g rowth wherein crack orientation is controlled by the slip direction and con tinued growth is dependent on the crack overcoming barriers to slip. Plasti city is assumed to occur as slip along planes inclined at 45 degrees to the surface. Problems where slip is limited to persistent slip bands are consi dered side-by-side with the problem where slip is not confined. Results for both monotonic and cyclic loadings are presented, with emphasis on the cra ck tip opening and sliding displacements. Both small and large scale yieldi ng are considered. Preliminary results are given for interaction with barri ers to slip, such as a grain boundary.