小曲率铝合金框形件弯胀成形数值模拟研究

目的 针对一种小曲率铝合金框形件成形后回弹大和起皱问题，对其进行弯胀复合成形工艺的数值模拟研究。方法 基于DYNAFORM软件对成形过程进行仿真，并通过对比分析零件的最大减薄率及圆角处的贴膜度，得出该零件最大液室压力的最优值为20 MPa，并基于该参数进行壁厚分布及回弹的模拟分析，最后，通过现场试验对该成形方案进行验证。结果 通过采用弯胀复合成形工艺方法，该零件的最大回弹量控制在2 mm以内，零件整体成形质量较好，无破裂、起皱现象。结论 该种成形方法较刚性模压弯及主动式充液胀形更具优势，能够有效解决小曲率框形件回弹大及起皱问题。

Numerical Simulation of Bending-Bulging Forming of Aluminum Alloy Frame-Shaped Part with Small Curvature

The work aims to solve the problem of large springback and wrinkling of small curvature aluminum alloy frame-shaped part after forming, and conduct numerical simulation study on the bending-bulging composite forming process. Based on the DYNAFORM software, the forming process was simulated. The maximum thinning rate and filming degree of the part were compared and analyzed. The optimal value of the maximum liquid chamber pressure was 20 MPa. The wall thickness distribution and springback simulation analysis was performed based on this parameter as well. Finally, the forming scheme was verified through site experiments. By adopting the bending-bulging composite forming process, the maximum springback of the part was controlled within 2 mm. The overall forming quality of the part was good. It was free from cracks or wrinkles. This forming method has more advantages than rigid die bending and active hydroforming bulging. It can effectively solve the problems of large springback and wrinkling of small curvature frame-shaped parts.