Effects of independent radial pressure loading paths on cup thickness distribution

Based on the forming need of aluminum alloy sheet parts with low plasticity and large height-diameter ratio, a new process of hydrodynamic deep drawing with independent radial pressure was proposed. The effects of loading paths on thickness distribution of the 5A06 aluminum alloy cylindrical cup with a hemispherical bottom were studied by numerical simulation and experiment. Employing the dynamic explicit analytical software ETA/Dynaform5.5 based on LS-DYNA3D, the range of loading radial pressure was determined initially to be 15-35 MPa, in which the aluminum alloy cylindrical cup with uniform thickness distribution and larger drawing ratio can be formed. The results indicate that under the reasonable match of chamber pressure, and independent radial pressure the serious thinning at the bottom of hemisphere can be effectively restrained. At the area of hemispherical bottom and the straight-wall close to the bottom, the thickness reduces. The thinning ratio of thickness reduces and the minimum thickness area of part moves from the region between hemispherical bottom and straight-wall down to the bottom gradually with the increase of radial pressure.