Forming Limit Prediction for Nickel Coated Sheet Based on Ductile Fracture Criterion by Finite Element Method

The material parameters of nickel coated sheet and low-carbon sheet were obtained firstly by tensile tests,and then,the stamping processing was simulated by finite element software Abaqus/Explicit.From the computation,the history of stress and strain in the coating and the substrate,the fracture initiation site and the distribution of the thickness were got,and the forming limit was predicted by using the Oyane ductile fracture criterion.The computation results based on Oyane ductile fracture criteria,experimental results and FE simulation results were compared.The results show that Oyane ductile fracture criterion can preferably predict the forming limit and facture initiation site of nickel coated sheet,and only keep a small difference with the experimental results.