Plastic Stress Intensity Factors in Steady Crack Growth,
Abstract
The asymptotic stress and deformation fields of a crack propagating steadily and quasi-statically into an elastic-plastic material, characterised by J sub 2 flow theory with linear strain-hardening, were first determined for the cases of mode III and mode I (plane strain and plane stress). Their solutions were approximate in that they neglected the possibility of plastic reloading on the crack faces. This effect was taken into account by the author who formulated the (eigenvalue) problem in terms of a system of first order. O.D.E.'s in the angular variations of the stress and velocity components. The strength of the singularity, serving as the eigenvalue, and the angular variations of the fields were determined as functions of the hardening parameter. The above analysis does not determine the amplitude factor of the near-tip asymptotic fields, or plastic stress intensity factor. In this work, a simple, approximate technique based on a variational statement of compatibility is developed under the assumption of small-scale yielding. A trial function for the stress function of the problem, that makes use of the asymptotic information in the near-tip and far-field limits, is postulated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA172146
Entities
People
- P. P. Castaneda
Organizations
- Harvard University