柔性压辊拉形中回弹的数值模拟

拉形是飞机蒙皮件的主要成形方法。柔性压辊拉形是一种新的拉形工艺,将传统的拉形过程中使用夹钳进行拉伸包覆的加载方式,改变为利用柔性压辊垂直下压的加载方式,使板料产生变形。对柔性压辊拉形成形球形件的过程和回弹进行数值模拟,分析加载量、板厚、板料与模具之间的摩擦系数等因素对回弹的影响。研究结果表明,在柔性压辊拉形方式下,成形件应力分布比较均匀,且在成形一定尺寸的球形件时,加载量越小,回弹量越大;板料越薄,回弹量越大;板料与模具之间的摩擦系数越大,回弹量越大。

Numerical simulation on springback during stretch forming with flexible-roller

Stretch-forming plays a key role in aircraft body panel forming.Flexible roller stretching is a new proposed technology which has changed the loading way in stretch forming.In traditional stretch-forming process the workpiece is stretched to cover the die with rigid jaw,however,in the new process it is loaded by a series of rollers with vertical moving path.The stretching of spherical parts with flexible-roller was simulated and the springback which depend on load volume,sheet thickness,sheet materials and the friction coefficient was analyzed.The results show that the stress of formed parts is uniform.The springback increases with decrease of the load and sheet thickness and increase of friction coefficient between the sheet and die.