Calibration of constitutive equations under conditions of large strains and stress triaxiality

Abstract

Constitutive equations were calibrated to improve their application in assessing a stress field in front of a crack under the conditions of large strains and stress triaxiality. The Bai–Wierzbicki method was adopted, and certain changes and new terms were introduced to incorporate material softening. Five shapes of specimens were tested to cover a wide range of stress triaxiality conditions and Lode factors. Tests were performed at three different temperatures, namely, +20°C, –20°C, and –50°C, and on three different materials obtained by three different heat treatments of S355JR steel.