| Automotive industry plays an important role in National Economy. It is animportant indicator of the level of a country's industry. Automotive body panelforming and mould design is the key technology to develop our mould industry,especially automobile. Die Design and Manufacture already become the mainbottleneck of vehicles for further shorten the cycle and improve the quality. Howto improve mold design and manufacturing standards is the main problem of theautomotive industry.With the development of numerical analysis techniques, plastic formingtheory, stamping technology and computer ability, numerical simulation was usedin the automotive panel die stamping process and the optimization of design. Thishas great significance to improve the research and development capabilities ofmold. The numerical simulation of automotive body panel forming is the researcharea of inter discipline including metal plastic forming theory and process,computational mechanics, CAD technology, computer graphics, etc. Usingnumerical simulation technology to simulate automobile panel stamping moldingprocess can predict the flow of metal, stress and strain, and temperaturedistribution, the force of mold, and possibly defects and failure form. Thisprovide an extremely powerful tool for optimizing process parameters and moldstructure. This has great significance to improve the quality of workpiece, reducematerial consumption, shorten the development cycle of product and reduce thecost of manufacturing.It is a very difficult project because sheet metal forming includes three kindsof nonlinearity such as material, geometry and boundary condition. The time is short when we began to research the sheet metal forming numerical simulation,and mainly concentrated in some colleges and universities. So far , domesticindustry and enterprises are still in the initial recognition of numerical simulationand simple stage of applications. Therefore, this dissertation focuses on theforming analysis and numerical simulation of automotive body panels whichcome from General Motor Corporation. When using UG software as modelingtools, DYNAFORM just imports the surface data in an IGES format. Thenumerical simulations are consistent with actual conditions. This dissertationresearch content includes:1．The paper Summarize the finite element method and the key technics ofthe sheet forming process. Summarize the development of plant FEM inside andoutside state. Researched the equation,elastic-plastic relationship, elementtheory of the large deformation FEM and the dynamic explicit algorithm. Thenthe paper discuss the contact realization. The forming process character and bugof panel are summed up. General steps and the key arc of the numericalsimulation of panel are brought forward. Some maters like model setup and meshgeneration are discussed.2．The author uses DYNAFORM software to simulate the forming of thefront fender of GM car, building up FEM model after technic analysis, fix ondirection and technic supplement.3．The outline of plant is worked out by BSE module of DYNAFORM, andthen the appropriate figure of the plant is fitted out. The fundamentality of theGravity Loading is discussed. The shape of plant on tools is worked out byGravity Loading, which provide the good foundation of simulation.4．The parameter of plant and tools are set. The effect of BHF, dummyvelocity ,gap of tools and friction parameter are discussed by using Orthogonalexperiment. The paper find when BHF is 600KN,dummy velocity is 5000mm/s,gap of tools is 0.77mm,and friction parameter is 0.15 ,the simulation result is thebest.5．The basic theory and application of equivalent drawbead model arediscussed, and the problems which are still unsolved are analyzed. Under threedifferent conditions, we discuss the role of the drawbead in the effect of theforming outcome. Through the compare and analyse, we set seven drawbead with different resistance, which greatly improve the resistance in the straight borderand the big circle, so that the blank can be evenly drew into the die, at last thedrawing insufficiency, local wrinkle and the crack can be polished up.6．Optimize the technic supplement. Through the way of optimization of theaddendum, we can not only solve the insufficient stretching problem, but also wecan reduce the springback of part. By optimization of the addendum, the qualityof the fender can be controlled in the way of forecast.7．According to the simulation results,I identified process, designed the dieand determined the structure and size of mold. According to the actual productionconditions, the fender was produced. By comparing the simulation results withthe product, the reliability of the simulation results was validated.
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