Research On Springback Analysis And Control Of The Automotive Body Beams Forming

As a high-efficiency, low-cost, low-power processing technology, sheet metal coldstamping has been widely used in the automotive industry. Nowadays, the unibodystructure are used more in the passenger cars, many important parts of the car body aremade of cold stamping process, such as the front and rear floor stringer，roof beams，threshold stringer, pillar stiffener and so on. Metallic material forming is a complexproblem which is affected by the plastic deformation in the mechanical, thus varietydefects often occur in the forming process, including rupture, wrinkling and springback.The springback, the most difficult problems, affect the assembly quality and the life ofthe workpiece directly.Automotive body beam parts have high-strength, large thickness and porous surfacefeatures. The out of range of springback is one of the most common problems afterforming. The springback, which will occur after the sheet metal forming, havingrelationship with the material performance, mold surface geometry, process parametersand other factors. This paper aims to explore the effects of process parameters on sheetforming and the effective methods of springback control from the aspects of numericalsimulation and the amendment of the numerical model.This paper first described the characteristics of the deformation and the mechanismof the springback of automotive body stamping, analyzed the factors that influencespringback, described the research of the springback prediction and control. Secondly,basing on a front bumper beam of a car, a simulation model was constructed by using theDYNAFORM software. The simulation of the forming and the analysis of the springbackwere performed. Several important process parameters that influence the springbackwere researched by orthogonal experiment. Integrated experimental method was used todetermine the appropriate process parameters. The improvements in processingtechnology reduced the amount of springback. Again, basing on the middle of the frontsuspension mounting beam of an electric car, the iteration springback compensation wasmade on the mold surface by using the CAE/SCP and the GSM/Compensator. The CADmodel was modified and reconstructed. Two solutions are verified by simulation, thepurpose of springback control is achieved. The results of the two compensation projectswere analyzed and compared. Finally, CMM measuring technology was used in terms of quality verifying. The comparison verification was made among the numericalsimulation results, the actual measured before compensation and the one aftercompensation. The results show that the method used in the paper that control springbackof the car body beam has the feasibility and practicality.