Analytical models of stretch and shrink flanging

Abstract This paper presents two modified analytical models for introflexion/stretch and outcurve/shrink flanges in sheet metal forming, based on the assumption of total plasticity theory and membrane strain. To examine the validity and accuracy of the two new models, the predicted and verified results of the present models are compared with other analytical models in the references and experimental data. Moreover, the models were used to predict the blank’s trim-line and the shape of a rolling-stock’s retractor with 8 mm thick metal panel, and to verify its flanging height. Finally, the influence of planar anisotropy of sheet metals on the flanging heights is also studied and discussed.