Abstract: Based on the iterative method，the iterative compensation mechanism was established and the criterion of the convergence for the iterative parameters was put forward for the springback problem in the plane deformation process of sheet metal. Moreover，it was proved that the axial length has convergence to the iterative compensation mechanism for the elastic-plastic deformation process of uniaxial tension and biaxial stretching in simple stress state. For the V-shape free bending of wide sheet metal，the convergence of the curvature and the bending angle was verified by theory and experiment. Furthermore，the iterative compensation mechanism was applied to the springback control of the free bending of the wide plate，and corresponding experiments were carried out. The results show that，the iterative compensation mechanism can predict the next compensation value based on the springback value of each test，so that the target bending angle with the error of less than 0.1% and the target curvature with the error of less than 0.5% are obtained after 2～3 iterations. Moreover，for the same forming process of same material，each compensation amount depends only on the iteration parameter difference before and after springback.

Key words: springback control, iterative compensation mechanism, convergence, free bending

摘要： 针对板材平面变形过程中的回弹问题，基于迭代法建立了迭代补偿机制，给出了迭代参量收敛性的判定准则。对于简单应力状态下平板单向拉伸和双向拉伸的弹塑性变形过程，证明了参量轴向长度对迭代补偿机制具有收敛性。对于宽板V形自由弯曲工艺，通过理论和实验验证了弯曲曲率和弯曲角的收敛性。进而，将迭代补偿机制应用于宽板自由弯曲工艺的回弹控制，对曲率和弯曲角分别进行了迭代补偿实验，结果表明，根据每次试验的回弹量，迭代补偿机制可以预测下一次补偿值，使弯曲工艺经过2～3次迭代，就获得了误差小于0.1%的目标曲率和误差小于0.5%的目标弯曲角，收敛速度很快。而且，对于同一材料的同一成形工艺，每次的补偿量只取决于回弹前后的迭代参量差值。

关键词: 回弹控制, 迭代补偿机制, 收敛性, 自由弯曲