A damage model for creep crack growth

✍ Scribed by T. C. Chang; C. H. Popelar; G. H. Staab

• Publisher: Springer Netherlands
• Year: 1986
• Tongue: English
• Weight: 612 KB
• Volume: 32
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00018350

✦ Synopsis

A model is developed for damage produced by the growth of isolated grain boundary cavities under power law creep. This damage model is combined with the small scale yielding stress and strain fields to predict the damage ahead of a stationary and a steadily propagating crack tip in an elastic-power law creeping material. A failure criterion, based upon the damage ahead of the crack tip attaining a critical value, is invoked. This criterion leads to predictions for the incubation time prior to initiation of crack growth and for the relationship between the remote stress intensity factor and the steady state crack speed. Results are presented for both elastic-primary and -secondary creep crack growth. In either case, there exists a minimum stress intensity factor below which steady state crack growth is not possible. Comparisons of the predictions of this model with others for steady state crack propagation in elastic-secondary creeping materials are also made.