Numerical simulation of hydrodynamic deep drawing with independent radial hydraulic pressure of aluminum alloy cylindrical cup with a hemispherical bottom

To satisfy the forming need of low plasticity materials and large height-diameter ratio parts, a new process of hydrodynamic deep drawing (HDD) with independent radial hydraulic pressure was proposed. Aiming at 5A06 aluminum alloy cylindrical cup with a hemispherical bottom, HDD with independent radial hydraulic pressure was studied by means of numerical simulation. By employing the dynamic explicit analytical software ETA/Dynaform based on LS-DYNA3D, and according to the forming process, a method to load hydraulic pressure was put forward. Based on the suspended region size and the curvature radius, the reasonable loading path was determined. And the effects of independent radial hydraulic pressure and liquid chamber pressure on the forming process and the sheet-thickness distribution were analyzed. The defects forming during forming process were discussed. The results indicated that the reasonable match between independent radial hydraulic pressure and liquid chamber pressure could reduce the radial tensile stress, restrain the serious thinning at the bottom of hemisphere and increase the drawing limitation of aluminum alloy cylindrical cup.