Numerical simulation of springback using enhanced assumed strain elements

The quality of springback prediction for a sheet metal forming process depends on a precise estimate of the elasto-plastic stress distribution throughout the metal sheet. The use of low-order conventional finite elements may be, without any proper treatment, responsible for low quality prediction because of volumetric and shear lockings. In this study, the enhanced assumed strain technique will be exploited for locking removal. The quality of the numerical simulation is evaluated through a comparison with other popular techniques like selective and uniform reduced integration. In contrast to the latter, and thanks to a full numerical integration scheme, the enhanced assumed strain element is very efficient in accurately capturing the development of plastic flow. This enables a reliable prediction of springback even with a rather coarse mesh. (C) 2004 Elsevier B.V. All rights reserved.