A Review of Sheet Metal Forming Evaluation of Advanced High-Strength Steels (AHSS)

This paper presents a review on the formability evaluation of advanced high-strength steels (AHSS), focusing on enhancing the limitations of necking-based failure criteria. It discusses complementary fracture and damage constitutive modeling approaches specifically tailored for formability evaluation, validated through both numerical and experimental methods. AHSS are increasingly used in sheet metal forming processes due to their lightweight, high-strength, and ductility properties; however, their multi-phase microstructure poses significant forming challenges. The research highlights the necessity for improvements in modeling forming behavior, particularly regarding necking-based failure criteria and direct fracture models. The conventional forming limit diagram/curve (FLD/FLC) is shown to have limitations in estimating direct fracture scenarios, including surface, edge, and shear cracks, especially under non-linear strain paths. Therefore, substantial research efforts are underway to develop advanced fracture constitutive models capable of predicting fracture scenarios that do not involve necking, which are increasingly prevalent in the context of AHSS. The scientific community is exploring various directions to enhance the accuracy of forming and fracture behavior predictions for components manufactured using AHSS.