Simulating sheet metal double-sided hydroforming by using thick shell element

Double-sided hydroforming has been widely used in production since it can improve the formability and surface quality of sheet metals significantly. This paper investigates the application of thick shell element in finite element analysis of sheet metal forming process with pressure reacting on both sides of the blank. The computational efficiency and accuracy of thick shell element is compared with that of solid element and traditional shell element based on a numerical example. Then a double-sided blank hydroforming experiment is carried out to validate the thickness prediction ability of thick shell element, and the results show that the normal stress in the thickness direction caused by double-sided pressure reduces the material thickness and increases plastic strain and effective stress in the forming zone. Thick shell element, which can reflect the influence of normal stress on sheet metal forming process, is effective in finite element analysis of double-sided hydroforming.