Experimental Study on the Forming Limit Curve of SECC Sheet Material

Numerical simulation in the sheet metal forming field helps engineers effectively solve various problems in the manufacturing of industrial products. In the forming, necking and fracture can occur on the products. These phenomena are caused by many reasons like the original mold design, technological parameters, and especially the limited forming of the sheet material. In order to accurately simulate the fracture phenomenon during forming, a forming limit curve (FLC) of the material is the most important input data. In this research, to determine the FLC of SECC sheet material by experiment method, a set of molds is first designed and manufactured according to the Nakazima model. Eight samples with various dimensions are then formed and measured major and minor strain points which are near fracture locations. This FLC data is verified through simulation of the forming process of the cup-shaped part. The simulated result of fracture height is compared with the experimental one and shows good agreement.