Numerical Simulation Research Of Variable Blank-Holder Force In Control Of Springback Based On Dynaform

Sheet stamping is the most important plastic working method, and it's applied to modern industry widely more and more. With the increasingly drastic market competition in modern industry, it requires not only high production efficiency, but also optimized control on the production process. So the continuous improvement of sheet stamping technique and process has been the research hotspot of sheet forming all along. With the swift and violent development of computer hardware and software, finite element method and computer graphics, the computer aided engineering(CAE)technology based on numerical simulation is widely used in sheet forming field.This paper introduced the finite element theory of sheet stamping. Discussed the process of computer simulation about the forming of sheet metal in detail; And introduced some CAE simulation analysis software which wide used in industry and research, then explain the software Dynaform which devised by ETA and LSTC about its function and simulate steps.Blank holder force(BHF)is one of the most important process variables controlling the sheet forming process for a given tool design. Researches have been carried out all over the world because of its crucial status. As a main control parameter to control the quality during sheet stamping, more reasonable BHF controlling is very important for fully using the deforming ability and raising the forming limit. In this paper, we deduce a new mathematics model of mutative BHE, and bring forward the "double-change" theory. then numerically simulate the control of Variable Blank-Holder Force(VBHF) with DYNAFORM software. obtain the optimum control curve of BHE at last.Springback is an essential thing in auto stamping parts, however, it should be controlled exactly for requirements of assemble and use. This thesis systemically analyzed the reason for how springback produced and the ways how to control it. The CAE simulation analysis software Dynaform was used to simulate the process of a typical sheet metal forming. The numerical simulation result indicates that the appropriate Variable Blank-Holder Force (VBHF) can improve the thickness and springback of sheet metal forming.In the paper, we explored the surface parts forming in detail. Including forming mechanism, mechanics model analysis, finite element numerical simulation, Variable Blank-Holder Force(VBHF) controlling, and bring out new formula and theory. The research approach and the result in this paper has some academic value and significance to study Variable Blank-Holder Force(VBHF) for sheet metal forming.