Numerical analysis of wrinkling phenomenon in hydroforming deep drawing with hemispherical punch

In this paper, effect of hydrostatic pressure on wrinkling phenomenon in hydroforming deep drawing (HDD) process of hemispherical cups with material AL6111-T4 was investigated numerically. Finite element analysis (FEA) codes could be used to understand the deformation behavior of a material during the forming process therefore ABAQUS/Explicit was used for simulations of processes and Failure criteria used in the analysis were based on the forming limit diagrams (FLDs). In addition Hill's anisotropic material model implemented in ABAQUS/Explicit was used. The simulation results of HDD and CDD processes were compared and results showed that using of hydrostatic pressure causes the sheet to stretch in the flange area and therefore push strains above the wrinkling limit curve in the forming limit diagram (FLD). As well as this external support provides a through-thickness compressive stress that delays the onset of tensile instabilities, also reduces the formation of wrinkles due to tensile frictional forces.