ASYMPTOTIC FIELDS FOR DYNAMIC CRACK-GROWTH AT A DUCTILE-BRITTLE INTERFACE

In this work, the asymptotic fields near a crack tip propagating dynam ically under plane strain conditions at a ductile-brittle interface ar e derived. The ductile material is taken to obey the J(2) flow theory of plasticity with linear isotropic strain hardening. The asymptotic s olution is assumed to be of the variable-separable form with a power s ingularity in the radial coordinate from the crack tip. Results have b een generated for different bi-material combinations over a range of c rack speeds. At a given crack speed, two solutions resembling the Mode I and Mode II asymptotic fields in a homogeneous material are obtaine d for all strain hardening between a lower and upper bound. The effect of mismatch in elastic stiffness and density, as well as strain harde ning of the ductile phase on the singularity strength, near-tip mixiti es and the angular stress and velocity functions are examined. Attenti on is focused on the influence of crack speed. on the above features o f the asymptotic solution. Copyright (C) 1996 Elsevier Science Ltd.