ANTIPLANE STEADY-STATE CRACK-PROPAGATION IN ELASTIC-VISCOPLASTIC MATERIAL

Anti-plane steady-state fast-crack propagation in an elastic-viscoplastic material is considered where the inertia effect is included through the normalized crack velocity parameter in addition to the material parameter. The stress field near the tip of a semi-infinite crack is intensified and can be characterized by the sum of an elastic stress intensity factor Ka and plastic stress intensity factor Kp both of which are coefficients of the 1 √r singular term with r being the distance measured from the crack tip. A numerical scheme is developed to solve the integral equation that relates the stress to the plastic strain rate. The changes in the size of the plastic zone surrounding the moving crack tip, which decreases with increasing crack velocity, are estimated. Results are also discussed with reference to the ways with which the material and kinematic parameters affect the intensification of the local stresses that are dictated by the external disturbance. © 1990.