PREDICTION FORMING LIMIT CURVE FOR SPCC MATERIALS BY GRAPHICS METHOD AND EXPERIMENTAL VERIFICATION

Abstract

In the field of sheet metal shaping deformation processing, particularly in the study of the forming limit curve (FLC) of materials, it is necessary to mention the modified maximum force criterion (MMFC) by Hora and colleagues. The proposal criterion has been widely used to estimate on the theory of forming limit curve of sheet metal. Based on this criterion, a graphical method was presented by Kim - Tuan to simplify the evaluation of the forming limit curve of sheet metal. This study presents an application of the graphical method to estimate the forming limit curve of SPCC steel materials which were used in the automotive industry. In order to confirm the accuracy of the graphic method, different hardening models of the stress-strain curve are used to estimate FLC for SPCC sheet material. The calculated FLC was then used as the input file for the finite element method (FEM) to predict the fracture height of the fuel filter cup and then compare with the corresponding experiment. The comparison results have demonstrated a good agreement between simulation and experiment.