PLANE-STRAIN NEAR-TIP FIELDS FOR ELASTIC-PLASTIC INTERFACE CRACKS

The plane strain problem of a stationary interface crack between two d issimilar ductile solids is studied asymptotically, where the ductile solids are assumed to be incompressible, elastic-perfectly plastic, an d obey the J(2)-flow theory of plasticity. Candidate asymptotic crack- tip assemblies of plastic and elastic sectors are proposed, and all as sociated admissible near-tip fields are presented. It is found that wh en the crack tip is fully surrounded by plastic sectors, then only iso lated, mode I type solutions exist. When an elastic sector appears alo ng the crack flank in one solid and all other sectors in the two solid s are plastic, a two-parameter family of solutions exists, which produ ces crack-tip stress variations similar to those of the mixed-mode as well as mode I slip-line fields for homogeneous ductile materials. Whe n each of the two solids contains an elastic sector along the crack fl ank, the crack-tip solutions are found to belong to a four-parameter f amily, which also resembles mixed-mode and mode I solutions for homoge neous solids. For completeness, the special case of ductile/rigid inte rfaces is also studied, and several one-parameter families of crack-ti p solutions are obtained, which are complementary to those already pub lished in the literature.