CRACKS ON BIMATERIAL INTERFACES - ELASTICITY AND PLASTICITY ASPECTS

Substantial progress has been made on the mechanics of interface fracture. An engineering program has emerged which allows the fracture resistance of interfaces to be measured and utilized. This recent development, assessed in an Acta-Scripta Metallurgica Proceedings, is discussed. Several results have been obtained on the plasticity aspects of interface cracks in which one (or both) of the constituent materials can deform plastically. The crack tip fields are members of a family parametrized by plastic mode mixity parameter-xi. The J integral scales each member field. Analyses of finite width crack geometries loaded by remote tension show that the effects of load, ligament plasticity and geometry on the near-tip fields are adequately accounted for by the J integral. The progress is summarized.