DP780高强钢U形弯曲回弹影响因素及优化

Influence Factors and Optimization of U-shaped Bending Springback of DP780 High-strength Steel

目的研究DP780高强钢不同参数对其U形弯曲回弹的影响。方法在室温下对DP780钢板材进行拉伸试验,获得其应力应变曲线。采用U形弯曲模具模型,利用ABAQUS有限元仿真软件对U形弯曲回弹进行分析,研究摩擦因数、压边力、冲压速度和凹凸模间隙对U形弯曲回弹的影响规律,并在此基础上设计正交试验以优化影响参数。结果在较小的摩擦因数下,回弹是有微小波动的,继续增大摩擦因数,回弹呈现减小的趋势;回弹随着压边力的增大先增大后减小;冲压速度的改变对回弹的影响不是很大;随着凹凸模间隙的增加,回弹逐渐增大。结论通过正交试验得到4个参数对回弹程度的影响,最佳参数组合为A_(5)B_(5)C_(3)D_(1),以此参数组合得出的侧壁角θ_(1)和法兰角θ_(2)最接近90°,回弹效果最好。

The work aims to study the influence of different parameters of DP780 high-strength steel on its U-shaped bending springback.A tensile test was carried out on DP780 steel sheet at room temperature,and its stress-strain curve was obtained.The U-shaped bending die model was used to analyze the U-shaped bending springback with ABAQUS finite element simulation software,and the influence laws of friction coefficient,blank holder force,punching speed and clearance between punch and die on the U-shaped bending springback were studied.On this basis,orthogonal experiments were designed to optimize the influencing parameters.The results show that with a small friction coefficient,the springback will fluctuate slightly.Continue to increase the friction coefficient,the springback will show a decreasing trend.The springback first increases and then decreases with the increase of blank holder force.Change of the punching speed does not have a great impact on the springback.With the increase of clearance between punch and die,the springback gradually increases.The influence magnitude of the four par¬ameters on springback is ob-tained through the orthogonal experiment,and the best parameter combination is A_(5)B_(5)C_(3)D_(1).Side wall angleθ_(1) and flange angleθ_(2) obtained by this parameter combination are the closest to 90°,and the springback effect is the best.