Investigating the impact of yield criteria and process parameters on fracture height of cylindrical cups in the deep drawing process of SPCC sheet steel

This study aims to accurately select a yield criterion by utilizing the identification coefficient method to describe anisotropic behavior using material parameters and finite element simulation. The influence of anisotropy is investigated and compared with experimental data. Three yield functions, namely von Mises, Hill’48R, and Hill’48S, are analyzed and their impact on numerical results is investigated using the Kim-Tuan stress–strain model for hardening law. The SPCC material (cold-rolled mild steel) is used for experimental validation. The main variables under study are the fracture height of cylinder cups and the evolution of simulated punch force. The deep drawing process of SPCC cylindrical cups is simulated using the finite element method (FEM) to evaluate the impact of the yield criterion on fracture height. The predicted punch force evolution remains consistent regardless of the yield criterion used, but the fracture height of cylinder cups is significantly influenced by the choice of yield criterion. The von Mises yield criterion leads to a significantly lower fracture height, while the Hill’48S yield criterion yields a fracture height that is too high. However, the results demonstrate that the Hill’48R yield criterion exhibits the most favorable agreement with experimental data for the fracture height of cylinder cups in deep drawing process. Additionally, the study investigates the influence of process parameters such as blanking holder force (FBH), nose radius of the punch (Rp), and limiting drawing ratio (Mt) on fracture height and addresses optimization problems. A highly accurate mathematical model is developed to predict fracture height based on FBH, Rp, and Mt, achieving a deviation of only 4.81% when compared to corresponding experimental values. These findings contribute significantly to the advancement of sheet metal forming technology in various industries, particularly in reducing defective product rates.