汽车纵梁冲压成形数值模拟及试验验证

Numerical simulation and experimental verification on stamping formability for automobile crossbeam

利用有限元模拟软件Autoform对汽车纵梁进行成形性分析,拟定落料→弯曲→切边、侧冲孔→翻边、上翻边→侧整形→切边、冲孔、侧切边、侧冲孔的工艺路线,并对回弹趋势进行预测。分析表明:当压边力增大到1500 kN时,纵梁尾部回弹减少到1.75 mm,即通过增加压边力可提高零件塑性变形的程度从而减少回弹。经过实际验证,数值模拟结果对起皱等缺陷的位置和大小预测较为准确;数值模拟可对回弹进行定性预测,利用其结果进行修正后反复模拟,可将回弹量由首次预测的13 mm缩减到最终的2 mm,再通过测量实际零件的回弹量并结合数值模拟结果进行补偿和修正,可进一步提高零件尺寸精度。

The formability of automobile crossbeam was simulated by finite element modeling software Autoform. Then, the process route of blanking →bending → trimming, side piercing →flanging, up - flanging → side sizing → cutting, piercing, side cutting, side piercing was designed, and the trend of springback was predicted. The results show that the springback at tail end of crossbeam reduces to 1.75 mm when the blank holder force increases to 1500 kN, that is to see that the plastic forming is improved and the springhack is de- duced by increasing blank holder force. The simulation result which verified by experiment indicates that the prediction of defect position of wrinkle as well as range is accurate. Then, the springback can be predicted qualitatively by numerical simulation, and the modified result is re-simulated over and over again. Therefore, the springback can be reduced from 13 mm to 2 ram. The springback obtained by practical part measurement is compensated and modified by combining with its numerical simulation result, and the part dimension accuracy can be improved.