针对金属薄板在普旋成形时易出现法兰起皱失效的问题，开展了铝合金封头普旋成形的有限元仿真及实验研究，分析旋压法兰边的弹性应变能及其增量与起皱失稳之间的关系，提出了铝合金材料的起皱判据.结果表明：在金属薄板普旋成形过程中，旋轮给坯料施加的变形力导致了法兰边的弹性应变能增加和振荡.由于弹性应变能增量幅值的增加，法兰边和旋轮作用区围成的扇形区域中出现了不稳定区域，故产生失稳起皱.基于Drucker公设提出了法兰起皱的判据，并建立了计算流程.通过普旋实验的验证可知，该判据能较准确地预测旋压成形时法兰边的起皱缺陷.
Wrinkling is a common failure when the sheet metal is formed in conventional spinning. Hence, a lot of work has been done to accurately forecast the flange wrinkling. In this paper, the finite element simulation and experiments are established to study the deformation characteristic of the aluminum-alloy hemispherical seal head in conventional spinning, the influence of elastic strain energy and elastic strain energy increment on flange wrinkling is found, and a theoretical flange wrinkling criterion of aluminum alloy is proposed. The results show that deforming forces causes the increases and fluctuation of flange’s elastic strain energy. Due to the increasing of elastic strain energy increment’s amplitude, the unstable range appears in fan shaped area surrounded by flange edge and active region of spinning roller, and then results in flange wrinkling. This research proposes a flange wrinkling criterion based on Drucker postulate and establishes calculation process. It is proved by the experiment that this criterion can accurately predict the flange wrinkling in spinning.
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