关键词: 回弹, 建模, 优化, 有限元法, 自由弯曲

Abstract: Springback in sheet metal forming process is due to the elastic deformation of the part during unloading. The design optimization of springback in sheet metal forming process is to control the final shape of the workpiece. Accurate prediction of springback is essential for the design of tools used in sheet metal forming operations. The manufacturing process design difficulty is formulated to minimize the difference between the shape of the desired workpiece geometry and the final analysis result after elastic springback. A finite element model is used to predict springback with contact evolution between the sheet and dies. A relatively simple springback benchmark (unconstra- ined bending of NUMISHEET’02) is solved. Sensitivity analysis done using FEM demonstrated that the magnitude of springback and the overall accuracy are highly influenced by the integration points, element size and material model. A conventional optimization method combined with FEM is used to obtain optimum parameters that can predict springback more accurately than 90%. The solutions are validated with experim- ental data in the literature.

Key words: FEM, Modeling, Optimization, Springback, Unconstrained bending