飞机复杂曲面蒙皮零件充液拉深技术研究

Hydrodynamic Deep Drawing for Complex Curved Skin Part of Aircraft

目的研究充液拉深工艺参数对飞机复杂曲面蒙皮零件成形质量的影响规律。方法以飞机灯罩蒙皮零件为研究对象,结合材料力学特性分析了零件的工艺性。基于破裂和起皱失稳条件理论研究了零件的加载工艺窗口,利用有限元方法分析了零起皱和破裂等缺陷,通过优化工艺参数和拉延筋参数获得了合格的构件。结果基于仿真优化结果,进行了模具设计和工艺验证实验,分析了实际充液拉深过程中缺陷产生的原因,为落差较大蒙皮零件的精密制造提供参考。结论对于具有多特征的复杂零部件,过渡曲面易产生起皱缺陷,仅通过调整液室压力或毛料尺寸的方法无法在保证不发生拉裂和贴模问题的前提下消除起皱缺陷。通过设置拉延筋来增加材料流动阻力、控制材料流动,可以消除过渡区域的起皱缺陷。

The paper aims to research the influencing rules of hydrodynamic deep drawing parameters on the forming quality of complex curved skin parts of aircraft. The aircraft lampshade skin parts were taken as the research objects to analyze the manufacturability of parts in combination with the mechanical characteristics of materials. The loading process window of parts was researched based on the fracture and wrinkling instability condition theory. The finite element analysis was utilized to explore defects such as wrinkle and crack, and the qualified components were obtained by optimizing process parameters and drawbead parameters. Based on the simulation and optimization results, the die design and process test were conducted, and the cause of the defect formation in the hydrodynamic deep drawing was investigated. This research can be thus used as a reference for the precise manufacturing of complex curved parts. For complex parts of multi-characteristics, excessive curve might generate wrinkle. Adjustment of cavity pressure or blank size cannot remove the wrinkle without fracture or die bonding. Increasing the flow resistance of material and controlling the material flow through setting drawbead can remove the wrinkle in the transition area.