飞机蒙皮振动辅助拉伸成形工艺分析

拉伸成形结束后,由于残余应力的存在导致蒙皮零件产生较大的回弹,会严重影响蒙皮的使用质量。基于回弹产生的原因,从工件的应力-应变机制阐述了振动减小残余应力的机理,提出了一种振动辅助飞机蒙皮拉伸成形的新工艺方法,给出了该工艺的主要参数——频率、振幅在应用选择上的依据条件及实际运用中可选择的合理范围。以飞机前缘蒙皮拉伸成形为例,通过数值仿真模拟,分析了施加振动对成形蒙皮零件回弹的影响以及频率、振幅对改善回弹的影响,并通过实验加以验证。结果表明,在飞机蒙皮拉伸成形过程中,施加振动可以更加有效地减小零件的回弹,当选取的工艺参数频率为30 Hz左右、振幅在1.5 mm左右时回弹值最小,效果最佳。

Analysis on vibration-assisted stretch forming of aircraft skin panel

After stretch forming, the residual stress in the formed panel causes springback, which seriously affects the assembly quality. Based on the cause of springback, the mechanism of residual-stress relief through vibration was described by the stress-strain mechanism of workpiece, and an vibration-assisted stretch forming of aircraft skin panel was proposed. Then, The basis condition of frequency and am-plitude for the main parameters of process in the application and the reasonable range of practical choice in the practical application were given. Therefore, for the stretch forming of aircraft front edge skin panel, the influences of vibration on the springback and the frequency and amplitude on the springback modification were analyzed by numerical simulation and verified by the experiments. The results show that adding vibration in the stretch forming process of aircraft skin panel can reduce springback effectively, and when the frequency and amplitude are 30 Hz and 1. 5 mm respectively, the sprinback is the minimum.