Plastic Yielding and Strain Hardening

Abstract

In the previous chapters we learned how to model plastic flow and dilatancy at failure. In shearing, however, plastic flow starts long before the failure. This phenomenon is called the plastic yielding. In a triaxial compression test on slightly overconsolidated clay (Figure 17.1a), the yielding first occurs at the yield point $Y({{{p}'}_{y}},{{q}_{y}})$, after which the stress-strain behaviour becomes irreversible