通过设定不同的边腿高度、边腿成形半径、板厚和材料属性等工艺条件,建立了柔性变截面辊弯有限元模型,对型材边腿在辊弯过程中的回弹现象进行了仿真研究和试验验证。结果表明:边腿高度在变截面辊弯回弹过程中起到主导作用,且不易受到其他因素的干扰,边腿成形半径对回弹角的影响作用仅次于边腿高度,板厚和材料属性对回弹角的影响相对较小。型材变截面边腿部分在折弯过程中沿成形方向会受到较大的附加变形,从而产生更大的纵向应变,成形完毕后其内部积累了更大的纵向残余应力,直接导致变截面边腿回弹量的增大。
By setting different technological conditions, such as flange height, flange forming radius, sheet thickness and material property, the flexible roll-forming FE model was built to simulate the springback phenomenon of the flange, and some experimental tests were carried out. The results demonstrate that the flange height, which is not easy to be interfered, plays a dominate roll in flange springback of flexible roll-forming. The flange forming radius also has a strong influence on the flange springback, but weaker than the flange height. Compared with flange height and flange forming radius, sheet thickness and material property have much less effect on flange springback angle. During flexible roll-forming, the flange height suffers a greater deformation in forming direction compared with conventional roll-forming, and then serious longitudinal residual stress is created. In this way, serious springback in the flexible flange is caused.