Prediction of spring-back and side-wall curl in 2-D draw bending
暂无分享,去创建一个
Accurate prediction of spring-back is essential for the design of tools used in automotive sheet-stamping operations. The 2-D draw bending operation presents a complex form of spring-back occurring in sheet-metal forming since the sheet undergoes stretching, bending and unbending deformations. These three sets of deformation can create complex stress-strain states in the sheet which result in the formation of side-wall curls after the sheet is allowed to unload. Accurate prediction of the side-wall curl requires using finite-element shell models which can account for curvature and stress variation through the thickness caused by bending and unbending of sheet. Since such models are generally computationally intense, an alternative and efficient method of predicting side-wall curls is desirable. This paper describes a novel and robust method for predicting spring-back and side-wall curls in 2-D draw bending operations, using moment-curvature relationships derived for sheets undergoing plane-strain stretching, bending and unbending deformations. This model makes use of the membrane finite-element solution to calculate spring-back. The accuracy of the model is verified by comparison with finite element (ABAQUS) and experimental results.
[1] Robert A. Ayres,et al. SHAPESET: A process to reduce sidewall curl springback in high-strength steel rails , 1984 .
[2] Farhang Pourboghrat,et al. Springback calculation for plane strain sheet forming using finite element membrane solution , 1992 .
[3] R. Hill. The mathematical theory of plasticity , 1950 .
[4] Neng-Ming Wang,et al. Analysis of bending effects in sheet forming operations , 1988 .