Drawbead Mechanics Characters And Influence On Subsequent Sheet Forming

As the automotive industry is developing rapidly, large panels becomes more and more complicated. The design and adjustment of drawbead, as a key measure to control the forming is focused on by many scholars and manufacturers . At present, the reseach on drawbead has obtained some progess, but the study of the forming mechnics of drawbead needs to be improved, and the study of its effection on subsequent forming of sheet metal is deficient. In this paper, using the nolinear finite element anaysis software MARC, based on large deformation elasto-plasticity theory, the research on the forming process of sheet metal with semi circle and rectangle drawbead is carried out. The change in mechanical parameters are analysed. moreover, on the base of the results, the paper generalizes the relation between the mechanical parameters (drawbead restraining force,forming drawbead force and holding force) and the structure parameters (height,radius and width), the drawbead design and adjusting principle are put forword. On the base of the above work, a study is made on the influence of drawead on the subsequent forming, the evolution of the thickness reduction and equivalent strain are analysed. The relation between the thickness reduction, equivalent strain and the structure parameters are studied systematily. Supplying a theory for the design and adjustment of drawbead...