Parameter calibration of ductile fracture criterion and its application on DP590

Abstract:

To study the ductile fracture mechanical properties of DP590 high-strength steel sheet, based on the DF2012 ductile fracture criterion, six types of tensile specimens under different stress states were designed to obtain the plastic flow and fracture parameters of the materials. In this study, an experiment-simulation hybrid method was used to calibrate the parameters of the ductile fracture criterion, for which accurately describing the plastic behavior before fracture is the key to calibrate the parameters of ductile fracture criterion. A newly proposed anisotropic Drucker yield criterion and a modified Voce hardening criterion were used to characterize the plastic behavior of DP590, and the constitutive model was compiled into a VUMAT subroutine by Fortran language and embedded into ABAQUS simulation software for tensile simulation of specimens. The experimental and simulation results show that the constitutive model can accurately predict the force curves of different specimens at different angles along the rolling direction. Based on the tensile experiments and the calibrated constitutive model, the parameters of DF2012 ductile fracture criterion were calibrated and the fracture locus of DP590 in two-dimensional space of stress triaxiality and fracture strain was constructed. And three typical ductile fracture criteria (Cockcroft-Latham, Clift and Rice-Tracey) were used for comparison. The results show that DF2012 ductile fracture criterion calibrated based on experiment-simulation hybrid method can reasonably construct the fracture locus of DP590 and accurately predict the fracture occurrence of tensile specimens under different stress states.