Damage Curve Determination of Dual-Phase Steel Based on Micromechanical Damage by Using Numerical Analysis and Experimental Investigation

Abstract

Dual phase steels are gaining a wide array of applications in the automotive engineering fields and can be subjected to forming/ stamping process due to their good mechanical properties. However, it shows complex damage mechanisms which results intricate prediction of sheet formability. In this study, the mechanical Gurson-Tvergaard-Needleman (GTN) model was used to predict the micromechanical damage of Dual Phase steel by calculating the evolution of voids in matrix due to mechanical loadings. To adequate calibrate the GTN parameters, it was defined by sufficiently comparative method between mechanical behaviors and numerical analysis. After that, to verify the accuracy of determined parameters, different stress states on tensile tests of different specimens were experimented and then, compared with numerical simulation based on GTN model with determined parameters. It shows a good agreement of force-displacement response. To develop the damage curve, the numerical analysis and experiments was used by considering tensile tests of various sample geometries for verification. The results of damage curve used GTN model, von Mises and Hill'48 yield criterion in the calculations, show accuracy and effect of yield models.