Prediction of Ductile Fracture Propagation of High Strength Steels in Automotive Structures
Initiation and propagation of ductile fractures in crashed automotive components using high strength steels are investigated in order to understand the mechanism of the fracture propagation. The fracture is often prone to occur at sheet edge in strain concentration zone at crash deformation. The fracture is extended intricately to inside of the structure, with the influence local stress and strain field. It is very important to predict the fracture initiation and propagation under crashed deformation for the reliable design of the light-weight structural by using ultra-high strength steels. In this study, 3-point bending tests are carried out with a hat-shaped part which have a notch and a hole to induce fracture. Three types of notch are machined by wire cut electric discharge process. The hole is located near the notch to investigate the influence on fracture propagation.