Three-dimensional finite element simulation of medium thick plate metal forming and springback

Degenerated shell element and membrane element have been widely applied in thin sheet metal forming analysis. However, for medium thick plate metal forming, especially in the case of typical double-sided contact problems such as local bulge forming or pure bending with a small radius, these two element models cannot accurately simulate normal extrusion deformation of the sheet metal. In this paper, a new finite element (FE) solver based on the solid-shell element dynamic explicit algorithm and implicit algorithm is developed for the simulation of medium thick plate metal forming and springback. The solid-shell element model considers bending effects with a thickness-direction multiple-point integration approach. The viscous damping hourglass control algorithm eliminates the spurious deformation modes activated by in-plane reduced integration (RI). The double sided contact analysis considering thickness variation describes the extrusion deformation in the thickness direction accurately. An improved plane-stress constitutive model in co-rotational configuration together with Hillʹs quadratic anisotropic yield criterion is employed to update the stress field. The solid-shell element obtains both solid-like and shell-like behaviours to simulate large membrane deformation, shear deformation and rotation. To test the performance of the solid-shell element, some numerical examples are taken and compared with experiments. The comparison results demonstrate that the solid-shell element model is competitive enough in the simulation of medium thick plate metal forming and springback.