A Simplified Anisotropic Yield Function not Requiring Parameter Optimization for Sheet Metals

Recently developed anisotropic yield functions can capture the material anisotropic behaviors through parameter optimization. However, sometimes the parameter optimization is not easy and does not always have a unique solution. This paper introduces an anisotropic yield function that does not require the parameter calibration process. This model simplifies the coupled quadratic and non-quadratic yield function in order to directly use the measured on-set of yielding stress and r-value data without the calibration process. The presented model is validated with five different materials for the prediction of stress and strain anisotropies. In addition, a cup drawing simulation is also presented to validate the simplified model in a practical metal forming simulation with the User-defined subroutine of ABAQUS. The results of this paper show that the simplified model can be effectively employed for the simulation of sheet metal forming processes.