Numerical Simulation Of Multi-point Forming With Different Blank-holder Way

Multi-point forming (MPF) is a flexible manufacturing technology for metal-sheet forming. It is based on numerical geometry information of product and the die is divided into a matrix of discrete elements which are directly driven by 3-D Model of product. The flexible forming process of metal-sheet is implemented by the contour surface of elements group. It can carry out dieless forming, optimizing forming way, no spring back forming and little machine forming large parts. MPF has found its extensive application fields such as the manufacturing of the fuselage of aircraft, the hull of ship, titanium alloy skull, city sculpture etc.For metal-sheet forming, a blank-holder has important function in preventing crackle, crinkle and improving the forming quality of metal-sheet. The blank-holder set of MPF is composed of forty blank-holder elements, and all of them are driven by its unique hydraulic equipment. When an appropriate thickness blank-holder is selected in MPF, the rigid blank-holder or the flexible blank-holder multi-point forming can be realized. The uneven blank-holder force metal-sheet forming is a foreland of international and in-country research. If supplying the blank-holder elements with several hydraulic equipments, it can realize uneven blank-holder force forming. When forming little curvature 3-D surface, the rigid blank-holder way can reach the quality of metal-sheet forming. Therefore this paper chooses large curvature 3-D surface formings as examples which have more complicated and more difficult forming process. With the finite element analysis (FEA) method, the MPF process with the flexible blank-holder, the MPF process with the rigid blank-holder and the MPF with uneven blank-holder force all have been simulated. This paper has studied their defects like crackle and crinkle,and...