Application of ductile fracture criterion to forming limit prediction of sheet metals

摘要

A criterion for ductile fracture is introduced into the prediction of forming limit in sheet meatl forming processes.From the distributions and the histories of stress and strain calculated by the finite element simulation the forming limit and the fracture initiation site are predicted by means of the ductile fracture criterion.Calculations are carried out for deep drawing and bore expanding of various sheet metals including laminated composite sheets.The results demonstrate that the application of the ductile fracture criterion allows the prediction of forming limit in a wide range of sheet metals.The relation between the criterion and the forming limit diagram is also clarified.