Forming Analyses And Numerical Simulation Of Sheet Materials

The sheet metal parts have been widely used in the automobile, aerospace and electronics industries owing to their light weight, great interchangeability, good surface finish and low cost. The deep drawing process is a main method used in mass production of sheet metal parts. Deep drawing process contains very complicated physical phenomena, involves three nonlinear problems, they are material, geometry and boundary of the mechanics science. The development of tooling for the sheet metal deep drawing is a time-consuming and expensive "trial and error" process by traditional way. In this paper finite element (FE) modeling is adopted to analyze this process in order to reduce the time and cost of tooling development.First, the craft characteristics and classifications of the figuration of the plank materials have been thoroughly discussed in this topic. The crinkling, pulling, and returning to play the blemish in the process of figuration are discussed, and their mechanism, factor and the method of controlling of the disfigurements above have been summarized. Second, a basic theory of the limited element is elaborated, and the common steps of how to use the theory are given. The most important of the thesis is analyzes the limited element theory of the elasticity and mold, which has been adopted in this thesis. In this thesis, a tool of the limited element mesh approximately to describe the work-piece and the die surface is adopted, on the basic of this, the method of time incrementing is also adopted to simulate the dynamic contacting state through the method above. The method how to judge the positions of the nodes contact is summarized, and the different of each positions are compared;Next, a calculation of flat surface contact is put forward, a revising procedure of node contact position is programmed to settle the phenomenon "the die lock" which is caused by using the shortest distance method to judge the node position, to make it be applicable to general software ANSYS. Last, the limited element of the automobile overlay's figuration is studied particularly in this thesis;The software CATIA is used to get an anti-operation with the three dimensions COMERO;Then the numerical simulation method of elasticity and mold limited element is used in the auto overlay's experimentations and the results of the imitating tests are analyzed by stress-meet an emergency according to the results of the imitating tests.It is a new approach of study and resolve the defect problem applying the ANSYS for studying prediction and analysis of autobody panel and tentatively. It has very important realistic meaning in improving the dimensional accuracy of the autobody panel, reducing the costs of tool manufacture and shortening the time cycle of tool development.