Research On Numerical Simulation And Springback Control Of Stamping For Body Cover

With the increasing number of automobiles every year,the automobile industry has entered a new era in which high-speed growth is shifting to high-quality growth.The high quality of the car is most intuitively reflected in the body cover.There are many molding defects in its stamping process,and the rebound defects are the most difficult to control.At present,domestic and foreign research scholars have conducted extensive research on sheet metal stamping forming,but there are still many difficulties in forming large aluminum alloy body coverings.This article takes the left front door outer panel parts of a certain model as the research object,and performs the numerical simulation of stamping forming.Through the multi-objective optimization of process parameters and rebound compensation,the defects in the simulation results are repaired to meet the production requirements.According to the basic theory of sheet metal stamping forming,the structural characteristics of the door outer panel are analyzed,and the whole process stamping forming plan is formulated.Using DYNAFORM software to carry out the drawing simulation and post-processing analysis.By analyzing the forming simulation results of different drawing bead layout schemes,the drawing bead arrangement method most suitable for the drawing of this part is obtained;Selection of materials provides a reference.Four process parameters(blank holding force,friction coefficient,maximum segmented rib resistance,concave die fillet radius)that have a great influence on forming are selected to design the central composite test.Relying on the test data,a second-order response surface model was established,and the influence of single variable and multivariable interaction on the forming quality was analyzed.Through NSGA-? genetic algorithm,the multi-objective optimization of the parameters of the door outer panel forming process was obtained,and a set of Pareto optimization solutions was obtained,which provided a reference for improving the production process.Select an optimized solution A,and perform the whole process(gravity loading-drawing forming-trimming-flanging shaping-punching-springback analysis)on the combination of process parameters to obtain the maximum thinning rate of the door outer panel 24.583%,the maximum thickening rate is 6.937%,both meet the production requirements;while themaximum rebound amount is as high as 22.847 mm,which is much larger than the rebound requirement.Aiming at the springback defect,the influence of the compensation factor on the springback of the AA6016 aluminum alloy car door outer panel was studied.After three iterations of the die surface springback compensation,the maximum springback of the door outer panel was reduced to 4.367 mm,which met the product quality requirements.After the compensated mold mesh is mapped through the curved surface,the mold profile can be generated to guide the mold processing,and at the same time it provides theoretical support for the production trial production of the new car cover.