Abstract
A new technique combining finite element (FE) simulation with real test to obtain the material constants used by ductile fracture criterion is proposed. First, two real tests with different stress conditions are conducted until fracture. Second, FE simulations, which completely simulate both of the tests, are carried out. Then, the stress and strain conditions from the FE simulation results are obtained at the same deformation state when the fracture occurred in the real tests. Finally, calculating two equations from each test, material constants can be easily determined without any measuring error. In this study, this technique was applied to the fracture prediction in circular-cup deep-drawing process, based on the material constants determined from uniaxial tensile test and circular-cup deep-drawing test. As a result of the fracture prediction, the fracture initiation could properly predicted and the availability of the technique was confirmed.
