Material modeling for accuracy improvement of the springback prediction of high-strength steel sheets

Improving the prediction accuracy of springback simulation are one of the most important problem because springback is major forming defect in sheet metal forming using high strength steel sheets. By applying the mixed hardening model by Lemaitre- Chaboche, which is possible to consider the Bauschinger effect under reverse loading path, prediction accuracy of springback were improved. And influences of material parameters of this model on springback deformation are investigated. To investigate the mechanism of the 3D springback, theoretical evaluation of simulation results before springback is carried out. It was found that 3D springback were reduced effectively by countermeasures obtained from that analytical results applied to the rear member model tests.