Effects of hydraulic pressure loading paths on the forming of automobile panels by hydro-mechanical deep drawing based on numerical simulation

As a part of automobile panel, outer door has a few characteristics, such as complex shape, big structure size and high quality forming needs. As a result, outer door needs multiple process and high costs by conventional drawing. In order to get rid of crack and forming deficiency in the stamping process, the numerical simulations of hydro-mechanical deep drawing (HDD) process was carried out. By using large nonlinear dynamic explicit analytical software ETA/Dynaform5.6, the effects of chamber pressure variations on the formability, and the effects of different loading paths on the wall-thickness distribution of the part were analyzed. The results indicate that under the reasonable chamber pressure loading path, the HDD can effectively control crack and forming deficiency, improve the thickness distribution uniformity, increase the die fittingness and stiffness. Complicated shapes car panel can be formed by one process with high quality.