Optimization Of Press Forming And The Springback Analysis Of Automobile Rear Door Outer Panel

The automobile cover has the characteristics of large size,high surface quality requirements and complex structure,and it is prone to wrinkling,cracking and springback in its stamping and forming.Therefore,its deformation law has always been a research hotspot.With the increase in light weight requirements and the increase in the application of high-strength steel,the difficulty of forming has also increased.This paper numerically simulates the forming process of an automobile rear door outer panel,optimizes the sheet forming process parameters and controls the rebound,and improves the forming quality of the automobile rear door outer panel.The specific research contents are:(1)According to the process characteristics,forming characteristics and material properties of the automotive rear door outer panel,the stamping process was developed,and the key technologies such as the stamping direction,the design process supplementary surface,and the binder surface were analyzed.The influence of blank holding force,friction coefficient,drawing resistance and die clearance on the formability of sheet metal was studied.The shape of the drawn sheet was determined.In combination with its characteristics and production actuality,we determined the initial blank holder force,drawbead arrangement,friction coefficient,die clearance and other process parameters of the automobile rear door outer panel.Autoform was used to numerically simulate the initial process parameters and simulation results was analyzed.(2)The influence of blank holder force,friction coefficient,drawing resistance and die clearance on the drawing quality of the automobile rear door outer panel was researched,and the appropriate reference values for each parameter were determined.According to the reference value,the three levels are selected respectively for the above four process parameters,and the parameters of the process parameters are optimized by the orthogonal test.The BP neural network was used to predict the maximum thickening rate and the maximum thinning rate of draw forming.The maximum error of BP neural network prediction results and Autoform simulation results was less than 9.09%.On this basis,numerical analysis was conducted on the optimal combination of orthogonal tests.The optimized layout of drawbeads was performed for the defects that occurred.Finally,the process parameters of the qualified drawbeads were determined,and the production experiment was carried out to obtain qualified product.(3)Using Autoform to carry out the springback simulation under the clamping constraints of the various processes of the automotive rear door outer panel,the results show that the parts in the gripping situation,the rebound is more serious.The mold spring compensation method was used to control the rebound of the automobile rear door outer door.The rebound was finally controlled within a reasonable tolerance range.After springback compensation,numerical simulation of the entire process results in good condition.The scheme was applied to the production and a qualified car rear door outer panel was obtained.