Finite element simulation of metal forming and in-plane crack propagation using ductile continuum damage model

The continuum damage model for ductile damage and ductile fracture is applied to metal forming and crack propagation by finite element method. The highly nonlinear equilibrium equation is formulated in order to include geometric, material nonlinearities and frictional contact condition. The effect of friction on the damage concentration is shown in the upsetting process. Then it is verified that the ductile fracture using this damage model is reasonable by the comparison with the experimental result in CCT specimen. The influence of the hole at the crack tip is shown through the numerical simulations of edge-cracked plates with different hole size. Finally, the strain energy release rate in this damage model is compared with J-integral using ABAQUS to relate the result of damage analysis to the concept of fracture mechanics.