Abstract
It is essential to model the Bauschinger effect correctly for sheet metal forming process simulation and subsequent springback prediction when material points are subjected to cyclic loading conditions. For an accurate prediction of springback, the Bauschinger effect must be considered to determine accurately the internal stress distribution within the sheet metal after deformation. In this paper the influence of Bauschinger effect on springback in reverse bending process is investigated numerically. Simulations are preformed for two materials, AA6111-T4 and high strength steel (HSS), while considering three different values of die radiuses and clearances. The obtained results show that the influence of Bauschinger effect is much more significant for the aluminum alloy rather than the HSS. Three different hardening models are utilized and their influences on springback prediction are studied. The isotropic hardening model predicts the same maximum punch load for bending and reverse bending and estimates the required maximum punch load for the second stage nearly twice that of the first stage.