Comparison between Lemaitre and Gurson damage models in crack growth simulation during blanking process

In this paper, the numerical results obtained by a finite element analysis in the case of sheet metal blanking process are compared with the experimental ones to verify the validity of Gurson and Lemaitre damage models in describing the initiation and propagation of cracks during the process evolution. The concept of continuum damage mechanics has been retained to describe the progressive damage accumulation into the sheet metal leading to the final rupture. During the analysis, the crack propagation is simulated by the propagation of a completely damaged area. The comparative study of the results obtained by simulations using different damage models and experimental ones, showed that Gurson damage model is not able to predict the fracture propagation path in a realistic way. Only Lemaı̂tre damage model gives good results.