Prediction of Fracture in Deep Drawing Process, Using Ductile Damage Criteria

In the deep drawing process, determination of the drawing depth and prediction of the time and the place that fracture occurs has been one of the important case studies which engineers tend to take into account. Because of a drastic reduction in design and manufacturing expenditures, numerical methods are extended to calculate the drawing depth during the process. In this paper, ductile damage model in which the stress triaxiality and equivalent strain are the most effective parameters on the damage growth and fracture of the material is used to predict fracture. For prediction the place and time of ductile fracture, according to ductile damage criteria, the fracture strain for various stress triaxiality values should be determined. To obtain the parameters of ductile damage model for St12 steel, some tensile tests have been performed on the notched specimens. Numerical simulation of deep drawing was performed using commercial finite element ABAQUS. Results obtained from simulation are in good agreement with the experimental ones and emphasize that using ductile damage model is appropriate to anticipate the place and time of the fracture during the deep drawing process.