Computer simulation of sheet metal forming based on damage mechanics approach

This paper presents an investigation of computer simulation to analyze the effects of plastic damage on the formability of VDIF steel under both proportional and non-proportional loading conditions. The simulation is carried out using LS-DYNA incorporated with a newly developed damage mechanics model and its damage criterion. Three forming processes, uniaxial tension, plane-strain deformation and biaxial stretching, are examined and deformation profiles are calculated and plotted. Finally, the forming limit strains are predicted for both proportional and non-proportional loading conditions, which are found to be in agreement with the test results.