Analytical and Numerical Simulations of Cylindrical Cup Deep Drawing for DC06 Sheet Sample

Generally speaking, all sheet metals demonstrate some degree of anisotropic plastic behavior. In cylindrical cup deep drawing process, this anisotropic behavior results in undesirable appearance on the top cup edge called earing. The optimization of cylindrical cup deep drawing process includes reduction of this undesired effect. For this purpose, numerical and analytical simulations of the cup drawing process can be of great importance. Numerous experimental, numerical and analytical studies indicate that the cup earing profile is closely related to the directional dependence of the plastic strain ratio called Lankford coefficient obtained in the uniaxial tensile testing of the sheet specimens with different orientations to the sheet rolling direction. In this paper, the cylindrical cup deep drawing process of DC06 steel sheet sample is simulated by the simple analytical approach and by the finite element program ADINA. Both adopted approaches utilize the experimentally determined directional dependence of the Lankford coefficient as input data. According to the standards, Lankford coefficient can be considered as a constant or as an incremental value depended on the strain accumulated during tensile test. Based to the available data for the considered material, analytical and numerical simulations are performed using the directional dependence of the constant Lankford coefficients and using the directional dependence of the instantaneous Lankford coefficients corresponding to the certain amount of the equivalent plastic strain. The obtained cup profiles are compared with the experimental data. By comparison, capabilities of the analyzed analytical and numerical models in predicting considered forming process are estimated.