Influence of hardening model on draw-bending springback prediction of DP980 dual-phase steel

Springback is a key factor affecting the dimensional and shape accuracy of coldformed high-strength steel parts, and the accuracy of high-strength steel springback prediction depends on the accurate material constitutive model. Therefore, it is important to study the influence of the constitutive model on springback prediction accuracy. In this paper, the parameters of the Yoshida-Uemori (Y-U) dynamic hardening model of DP980 dual-phase steel were determined through tension-compression tests with two different strain levels and multicycle tension-compression tests. Based on the draw-bending test platform, the influence of roll radius and normalized back force on the springback of DP980 was investigated. Additionally, the effect of different hardening models (Swift model, Y-U model) on the prediction of draw-bending springback was studied by using Abaqus finite element analysis software. The results show that increasing the bending radius and normalized back force can reduce the springback angle and side wall crimp. The tension-compression testing strategy shows little effect on the calibrated Y-U model parameters of DP980 dual-phase steel. The Y-U model can achieve better prediction accuracy for draw-bending springback angle and curvature compared to the Swift isotropic hardening model.