基于补偿因子的直弯边下陷零件回弹补偿研究

Research on springback compensation for straight flanging jogged part based on compensation factors

橡皮成形是飞机钣金零件制造的一种重要成形工艺,回弹是橡皮成形过程中主要缺陷之一.为提高钣金零件橡皮成形效率,基于补偿因子对下陷区回弹补偿进行研究,实现钣金零件一步法成形.首先对弯曲回弹公式进行推导,结合弯曲过程中刚度概念引出补偿因子作为直弯边下陷零件回弹补偿公式;然后利用CATIA二次开发功能将补偿公式写入程序并与数据库进行连接,并对直弯边下陷零件进行回弹补偿;采用Pamstamp 2G软件对橡皮成形过程进行有限元模拟,通过实际成形试验对带补偿因子的回弹公式进行验证,最后将模拟值和试验值进行比较.结果表明:有限元模拟过程能够很好的预测回弹,补偿结果达到精准成形要求且误差在0.5°范围内,成形压力对回弹影响很小.对于下陷成形,需要较大的成形压力才能达到一次成形的目的,验证了补偿因子回弹公式的可靠性.

Rubber forming is an important forming process for the manufacture of aircraft sheet metal parts.Springback is one of the major deficiencies in rubber forming. In order to improve the rubber forming efficiency of sheet metal parts,the compensation of jogged zone springback was studied based on the compensation factors to achieve one-step forming of sheet metal parts. Firstly,the bending springback formula was deduced,and the compensation factor was deduced by the concept of stiffness in the bending process as the springback compensation formula of the straight flange jogged part. Then the compensation formula was written into the program by the secondary development function of CATIA and connected to the database. The Pamstamp 2 G software was used in the finite element simulation of the rubber forming process. The springback formula with compensation factor was verified by the actual forming test. Finally,the simulation value and the test value were compared. The results show that the springback could be well predicted by the finite element simulation process,the compensation result reached the precision forming requirement and the tolerance was within 0. 5 °. The forming pressure had little effect on the springback. For jogged forming,a larger forming pressure was required to achieve the purpose of one-step forming,and the reliability of the springback formula of the compensating factors were verified.