金属板材多道次渐进折弯成形的回弹补偿

Springback compensation of multiple-step incremental air-bending forming of sheet-metal

在模具型面的位移修正法(DAM)、平滑的位移修正法(SDAM)和成形传递函数法(DTFM)的基础上,提出一种基于傅里叶结合小波变换的离线闭环控制迭代算法,进行折弯凸模型面修正,实现回弹补偿.为减少模具和人工成本,借助数值模拟替代闭环控制迭代修正所需的工件成形回弹试验.将上述凸模型面修正算法应用于半椭圆形工件的渐进成形加工,平均误差是-0.493～0.573 mm.实际应用结果显示所提出的算法对减少渐进成形回弹误差是合理可行的.

在模具型面的位移修正法（DAM）、平滑的位移修正法（SDAM）和成形传递函数法（DTFM）的基础上,提出一种基于傅里叶结合小波变换的离线闭环控制迭代算法,进行折弯凸模型面修正,实现回弹补偿.为减少模具和人工成本,借助数值模拟替代闭环控制迭代修正所需的工件成形回弹试验.将上述凸模型面修正算法应用于半椭圆形工件的渐进成形加工,平均误差是-0.493～0.573 mm.实际应用结果显示所提出的算法对减少渐进成形回弹误差是合理可行的.An iterative algorithm of of-line closed-loop control for correcting sheet metalair-bending punch was developed based on fast Fourier and wavelet transforms, after displacement adjustment method （DAM）, smooth displacement adjustment method （SDAM） and deformation transfer function method （DTFM） for die surface were studied. The springback tests of workpieces forming, needed in the iterative process of close loop control system, were substituted by finite element model （FEM） simulation. Then, a semiellipse-shape workpiece, whose average errors were -0. 493-0. 573 mm, was made with the corrected punch solved by the above algorithm and simulation data. The results show that the mould correction algorithm with Fourier and wavelet transform is reasonable and the means of FEM simulation are effective. It can be taken as a new approach for optimization design of sheet-metal air-bending mould.