Effect of punch profile on thickness distribution in hydromechanical deep drawing of conical-cylindrical parts

Hydro-mechanical deep drawing assisted with radial pressure (HDDRP) is used in industry to produce complex parts from sheet metals. This process is affected by parameters such as : pressure path, geometrical parameters of punch and die, friction between punch and sheet, etc. Investigating these parameters to acquire optimal parameters to produce the desired part is essential. In this study, the effects of the radius of punch tip and the radius of the transition zone from conical to cylindrical geometry, on forming and thickness distribution of parts have been studied. In performing the investigation, a specific geometry was considered for punch and different radiuses for punch tip and the transition zone were selected. The type of the sheet material examined is St14 steel. First, the process was simulated by the finite element simulation software, ABAQUS 6.9, and then some experiments were done to check the accuracy of the simulations. There is an acceptable conformity between the results. The results showed that the radius of punch tip is more effective than that of the transition zone, so with increasing the radius of punch tip, the minimum thickness increases and thickness distribution becomes more uniform.