Calibration of constitutive equations under conditions of large strains

摘要

In the paper the calibration technique of the real stress - logarithmic strains uniaxial curves is proposed, based on the modified Bai-Wierzbicki proposition. The material softening was included before the final failure. Four shapes of specimens were tested, to cover a wide range of stress triaxiality conditions and Lode factors. Tests were performed at temperature +20°C, on S355JR steel with ferrlitic-pearlitic microstructure.