双向曲率板材冲压成形补偿回弹的逆解算法

Inverse solution on springback compensation in double-curved sheet metal forming

给出了直接计算双向曲率冲压模具补偿回弹所需预弯尺寸的逆解公式。通过计算两个方向上的塑性弯矩来建立算法的数学模型。为验证合理性,用有限元软件对不同厚度、期望成形半径为200mm的具有等向曲率的工件进行模拟。结果显示,回弹后的最大法向误差由未补偿的1.96mm降至补偿后的0.52mm,并且板厚越厚,回弹越小,模拟结果与计算值基本相符。因此,计算方法可以为初始模具型面尺寸设计提供参考。

An inverse formula to calculate pre-bending size after double-curved forming was given,The mathematical model was set up by calculating plastic moment in 2 directions.Different thickness and target forming radius of 200mm with equal curvature workpiece were used to simulate by a FEA software to verify the algorithm.Results indicate that maximum normal error decreased from 1.96mm to 0.52mm after springback,the more thickness of the shell,the less the springback,simulated results coincide well with theoretical value.Thus,the formula may be used to provide a reference for the initial die design.