A family of plane strain crack tip stress fields for interface cracks in strength-mismatched elastic–perfectly plastic solids

Asymptotic crack tip stress fields are developed for a plane strain crack located on the interface between two incompressible, elastic–perfectly plastic solids, with matching elastic properties, but mismatched yield strengths. The complete range of normal versus shear tractions on the interface at the crack tip is analyzed. In the limit as the yield strength mismatch vanishes the asymptotic stress fields for the interface crack approach established crack tip fields for homogeneous bodies. The crack tip stress fields are assembled from combinations of centered fans, constant stress sectors and elastic sectors. All the stresses within each material region are continuous while traction continuity is maintained across the interface. These asymptotic stress fields are verified by comparison with small-scale yielding finite element solutions obtained for various remote load mixity using boundary layer formulations (Rice, 1967) .