双层板球冠形构件普旋法兰起皱预测

Prediction for flange wrinkling of dual-metal sheet in conventional spinning of spherical crown part

针对双层板在普旋成形时易出现法兰起皱的问题,提出了一种理论预测方法。首先对双层板在旋压成形过程中法兰的受力情况进行了分析,然后基于塑性理论对弯曲应变能和外力做功分别进行了求解计算,并根据能量平衡方程建立了解析模型,用来确定无法兰起皱缺陷的成形极限。计算结果表明,旋轮进给比和板料厚度对法兰起皱的影响显著,旋轮进给比越大,板料越薄,双层板在普旋阶段的成形极限越小,法兰越易出现失稳起皱。以SUS430/Al3003双层板为例进行工艺实验,研究发现,利用解析模型得到的计算结果与实验结果一致,证明了上述理论预测模型的可靠性。

Aiming at the problem that the flange wrinkling is easy to occur in conventional spinning forming of the dual-metal sheet,a theoretical prediction method was proposed.Firstly,the force on flange in spinning forming process of dual-metal sheet was analyzed,then the bending strain energy and the work done by the external forces in conventional spinning forming were calculated based on the plastic theory,and an analytical model was established according to the energy-balance equation to determine the forming limit of no flange wrinkling defect.The calculation results show that the effects of roller feeding rate and sheet thickness on flange wrinkling are significant.The larger the feeding rate is,the thinner the sheet metal is,and the smaller the forming limit of dual-metal sheet in conventional spinning is,the more likely the flange is to winkle.SUS430/Al3003 dual-metal sheet was used as the example to carry out the experiments.It is found that the calculation results obtained by the analytical model are consistent with the experimental results,which proves the reliability of the theoretical prediction model.