不同材料强化模型对QP钢回弹预测精度的理论及应用研究

Theory and application study on springback prediction accuracy for QP steel with different material hardening models

对第3代先进高强钢QP980和QP1180材料的4种强化模型参数进行了分析,基于特征帽型零件比较了模型的回弹预测精度,然后采用最优模型在某车型A柱零件上开展回弹分析并进行实际零件预测结果验证。研究结果表明:QP980和QP1180均表现出一定的包申格效应; Chaboche、NSK Swift和Y-U模型均能描述材料的包申格效应,但Y-U模型拟合效果最好,等向强化模型Swift不能描述包申格效应;比较4种模型对帽型零件的回弹计算结果和试验结果可知,Y-U模型预测精度最高;比较Y-U模型在A柱零件关键截面上回弹预测与试验结果可知,轮廓重合性较好,并在一些关键点进行比较,计算与实测误差较小,说明Y-U模型对该零件回弹表现出较高的预测精度。

The parameters of four hardening models for the third generation advanced high strength steel QP980 and QP1180 were analyzed,the springback prediction accuracy of the models was compared based on the characteristic hat shape part.Springback analysis of the A-pillar part was conducted to verify the accuracy of the optimum model.Results show that both QP980 and QP1180 show a certain Bauschinger effect.Chaboche,NSK Swift and Y-U models can describe the Bauschinger effect of the material while the equivalent strength Swift model cannot,and the Y-U model has the best fitting effect.By comparing the calculation results and test results of springback for hat shape parts,it can be known that Y-U model has the highest prediction accuracy.Material springback prediction with Y-U model and tested springback at key sections of A-pillar parts were compared,and the contour coincidence is good,also the simulation errors at key points are small,which show that the Y-U model has a high springback prediction accuracy.