Advanced material model for numerical simulations of fine blanking

摘要

Advanced manufacturing processes, including fine blanking, are widely used in the mass production of sheet metal parts. In the present article, numerical modelling and a real-world test of fine blanking are discussed with a focus on material characterization. The material was 1.4301 stainless steel and its model was constructed using measured mechanical properties. Tensile tests, plane strain tests and shear tests were carried out to determine steel characteristics under various stress states. All the tests were performed at room temperature and under quasi-static conditions. Local strains were determined using the ARAMIS digital image correlation (DIC) system from GOM company. After testing, metallographic analysis of the specimens was conducted for characterizing their fracture surfaces. By correlating the data from the DIC system, results of numerical modelling and metallographic examination, the instant of failure initiation in a specimen can be determined. When a ductile failure model is calibrated against tests under various stress states and used for modelling of blanking, it improves the description and the accuracy of the computational model of the process. The choice of the failure model has a substantial impact on the calculated magnitude of fine blanking force. To validate the material models chosen, an additional fine blanking test and metallographic examination were performed in order to assess the creation and shape of the sheared edge. A material model developed and validated by this procedure becomes useful in the design and optimization of real-world blanking processes.