DAMAGE ACCUMULATION FOR GROWTH OF ANTIPLANE CRACK IN WORK-HARDENING MATERIAL

Elastic-plastic solutions of an anti-plane crack in an infinite body a re used in conjunction with a continuum damage model to describe the c onditions necessary for the onset of crack instability, fatigue crack propagation due to cyclic loading, and rates of crack growth due to ti me dependent events. A power law relates the stress to the strain of t he material. The damage, which invokes nucleation, growth and coalesce nce of microvoids due to elevated strain, is confined to the plastic z one surrounding the crack tip. For applied loading below the yield str ess, the small-scale and large-scale yielding solutions are used to de termine the influence of strain hardening on crack instability and fai lure. Crack growth due to cyclic loading and time-dependent deformatio ns are studied using the small-scale yielding solution of the deformat ion theory of plasticity. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.