回弹比矩阵及回弹比特征量在双曲度板成形回弹描述和补偿中的应用

Application of springback ratio matrix and springback ratio feature value in springback description and compensation of double-curved plate forming

回弹补偿是活络方形压头可重构模具成形船体双曲度外板时遇到的主要难题。本文参考单曲度板回弹比表达方法,引入针对双曲度板材描述离散点以及整体回弹大小的回弹比矩阵及回弹比特征量,并对文献中单曲度板的回弹数据进行了描述,得到的结论与文献一致。同时对典型双曲度板进行了冲压成形实验,并采用本文提出的回弹比矩阵及回弹比特征量对回弹数据进行描述。结果表明:在双向曲率半径分别相等时,马鞍形板的回弹显著小于帆形板;弹塑性理论推导出的回弹比结果与实验数据的回弹比结果相一致。基于回弹比矩阵,本文提出了一种新的回弹补偿算法,通过对比发现基于回弹比矩阵的补偿算法的补偿效果更好。

Springback compensation is the main difficulty in the forming of double-curved hull plates by re⁃configurable mold.In this paper,springback ratio matrix and springback ratio feature value were proposed by referring to the expression of springback ratio of single-curved plate.Springback ratio matrix describes the springback value of local point of plate while springback ratio feature value describes the whole plate.The conclusion of springback of single-curved plate using springback ratio matrix and springback ratio feature value was consistent with that of the literatures.The forming experiments were conducted and the springback results were described by springback ratio matrix and springback ratio feature value.The results show that springback of saddle-type plates is less than that of sail-type plates when the radii of curvature in both direc⁃tions are equal,and the springback ratio results based on elastic-plastic theory agree with those of the experi⁃ments.A new springback compensation algorithm based on springback ratio matrix was proposed.It is con⁃cluded that the springback compensation algorithm based on springback ratio matrix has a better compensa⁃tion effect.