The Numerical Simulation Of Stamping Fracture Of Tailor Rolled Blank

The energy crisis and environmental protection requirements promoting the development of the automotive lightweight.The application of tailor welded blank has a great effort on improving the lightweight of the automotive,while the tailor rolled blank is a lightweight material based on new material processing technology after tailor welded blank.Due to the tailor rolled blank can be optimized according to the strength requirements of parts,can effectively reduce the weight of parts,so the application more and more widely.Due to the fracture is the main defects of stamping specimen,it is necessary to accurately predict the fracture defects of the sheet metal.While the tailor rolled blank has the thickness transition zone,so the research methods has some differences with ordinary blanks,and it is necessary to study the forming performance of the tailor rolled blank to make it better applied to the actual production.In this paper,using the method of finite element to separate the thickness transition zone into a limited number of plates with the same thickness.And through the tensile test of the same thickness blank get the stress and strain data,then interpolated the stress and strain data get the mechanical parameter of the material.Secondly,the ductile fracture of the metal material is researched from the viewpoint of microscopic damage mechanics,and improve the Rice-Tracey fracture criterion to make it applied more widely.At the same time,the secondary development of LS-DYNA is carried out,and the fracture criterion is integrated into the numerical simulation.The fracture defects of sheet metal stamping can be predicted more intuitively and conveniently.And the parameters of fracture criterion are determined by the combination of experiment and simulation.For the improved fracture criterion,it is necessary to verify the accuracy.It can be used to predict the stamping fracture of the tailor rolled blank.Finally,the improved fracture criterion is used to determine the fracture standard,and predicate the fracture defects of box part test specimen.Using the fracture criterion predict the location of fracture,and analyze the simulation result.As well as the experimental results were compared and verified,the results show that the improved fracture criterion is more accurate than the Rice-Tracey fracture criterion.