ANALYSIS OF AXISYMMETRIC SHEET HYDROFORMING PROCESS

In this paper an analytical model considering die arc and variable thickness for dome portion of the deformed sheet is proposed for axisymmetric sheet hydroforming process. The aim of the analysis is to calculate the thickness variation along the final shape and the required forming pressure in two cases of high and low blank holder forces. For analysis، first a mathematical relation for the thickness distribution in dome portion is proposed. Then، by applying the incompressibility law in plastic deformation the thickness distribution is calculated. After that، with the calculated thickness variation، the strains and the stresses all over the deformed sheet and the strain energy are determined. By equating the total strain energy with the external work، the forming pressure is calculated. The predictions of the proposed analytical model are validated by comparing them with the results available in the literature and they are found to be in good agreement.