ROLE OF CONTINUUM DAMAGE IN CREEP CRACK GROWTH.

Abstract

Theories that have been used to predict the rate of growth of cracks due to creep are reviewed and assessed. The need is expressed for a sounder understanding of the mechanisms by which creep crack growth takes place The aim of this paper is to answer the question: can continuum damage mechanics provide the mechanism by which cracks grow by creep? The paper reports the results of theoretical and experimental studies on internally and externally cracked, plane strain, tension members, in an aluminum alloy, in copper and in 316 stainless steel, all of which undergo high temperature creep rupture under steady loads. Theoretical predictions of lifetimes, expressed as a representative rupture stress, of damage fields and of crack growth are made by using a previously developed finite element system based on the theory of continuum damage mechanics. Refs.