Elastic-Plastic Stress Field in Cracked Bodies

Abstract

The linear elastic analysis of the stress field in cracked bodies, dealt with in the preceding chapter, applies, strictly speaking, only to ideal brittle materials for which the amount of inelastic deformation near the crack tip is negligible. In most cases, however, there is some inelasticity, in the form of plasticity, creep or phase change in the neighborhood of the crack tip. A study of the local stress fields for the three modes of loading showed that they have general applicability and are governed by the values of three stress intensity factors. In other words, the applied loading, the crack length and the geometrical configuration of the cracked bodies influence the strength of these fields only through the stress intensity factors. We can have two cracked bodies with different geometries, crack lengths and applied loads with the same mode. The stress and deformation fields near the crack tip will be the same if the stress intensity factors are equal.