An Investigation of Wrinkling and Thinning in Hydroforming Deep Drawing Process with Hemispherical Punch

In this paper, the effect of hydrostatic pressure on wrinkling phenomenon in the HDD process of hemispherical cups with material AL6111-T4 has been numerically investigated. The simulation results are in excellent agreement with the experimental results obtained from the work of Abedrabbo et al., [1]. ABAQUS/Explicit was used for simulations of processes, and failure criteria used in the analysis were based on forming limit diagrams (FLDs). Furthermore, Hill’s anisotropic material model implemented in ABAQUS/Explicit was used. The results showed that hydrostatic pressure causes the sheet to stretch in the flange area, and this external support provides a compressive stress that delays the onset of tensile instabilities and reduces the formation of wrinkles due to tensile frictional forces. In the second section of this paper, the effect of maximum counter pressure profile on the thinning distribution in HDD process has been studied numerically. Results of this work showed that minimum thinning can be obtained by using a maximum counter pressure profile of 17 Mpa. When the pressure exceeds this limit, rupturing will occur.