On the evaluation of monotonic and cyclic plastic zones

Abstract

This paper reviews and compares the various approaches for finding monotonic and cyclic plastic zone sizes for elastic-perfectly plastic and strain hardening materials. All through the analysis Ramberg-Osgood relationship has been used representing the monotonic and cyclic stress-strain curves. The results for elastic-perfectly plastic materials are compared with those available using finite-element technique. The ratio of monotonic plastic zone sizes strain hardening and elastic perfectly plastic materials are found to be related to the Ramberg-Osgood index n. The values of cyclic plastic zone size are found to depend upon factors like crack opening stress, material properties and specimen geometry. The cyclic plastic zone size obtained in this paper compare well with those given by Antolovich.