Research On Process Parameters Optimization And Springback Compensation Of High Strength Steel For Automobile Front Beam Sealing Plate

Automobile industry is one of the foremost industrial pillar industries in our country.It drives China’s rapid economic development and solved employment problems of a large number of population.The production of car body panels is one of the most important parts of the automobile manufacturing process.The production quality and qualification rate of the car body panels directly affect the quality of the entire vehicle and the development cost.The biggest quality problems of automotive body panels in the process of stamping are springback,cracking,and wrinkling.Therefore,it is very important to carry out research on the optimization of stamping process parameters and springback compensation.The main influencing factors of automobile panels forming quality include:shape of mold surface,blank holder force,setting of drawbeads,blank size and friction coefficient.This paper mainly studied the influence law of these influencing factors on the main quality problems in the stamping process of automotive panels,numerical simulation technology,multi-objective optimization algorithm and reverse springback compensation technology were used to optimize the forming quality.In this paper,the lightweight high strength steel front longitudinal beam closure plate was set as the research object.Aiming at the forming quality problems in the stamping process,such as springback,cracking,wrinkle and so on,the multi-objective optimization of stamping process parameters was used to obtain the parameter combinations used in actual production.And finally,after the blue-sweep-based profile springback compensation,the qualified automotive front longitudinal beam closures were obtained.Based on the above content,the paper mainly carried out several aspects of research:The structural characteristics of the front longitudinal beam panel plate were analyzed;the supplementary surface of the component was designed,and the shape and size of the blank were determined.And a stamping forming process plan for the front longitudinal beam closure plate was obtained.The stamping finite element analysis model of the front longitudinal beam closure plate of the automobile was established,after the process parameters that have a great influence on the forming quality of the front longitudinal beam sealing plate were selected as the factors:blank holder force,the resistance coefficient of draweads,the coefficient of friction,etc.Combined with the results of finite element simulations such as forming limit diagram,thinning rate and springback distribution,single factor analysis method was used to study the influence of various parameters on the maximum thinning rate and the maximum springback.And the appropriate value ranges for each process parameter were got.The maximum wrinkling trend function,the maximum tearing trend function and the maximum springback function are used as evaluation functions for multi-objective optimization.Segmented drawbeads were used,and a central composite experiment design method is used to obtain a specific experimental scheme.Simulations are performed in finite element software.The experimental data of simulation were normalized.The response surface method and the weighted method were combined to obtain the second-order response surface model between the objective function and the influencing factors.The significance and reliability of the model were also tested.The optimization toolbox function fmincon in MATLAB was used to solve the established response surface model,and the optimal combination of parameters is the blank holder force F=900kN,segmented drawbeads coefficient d₁=0.14,d₂=0.1,d₃=0.45 and d₄=0.45,and the optimized parameters were again verified by finite element simulation.The results show that the optimized parts have good quality without defects such as crack and wrinkle.The springback problem of the front longitudinal beam sealing plate is studied.Firstly,the optimized parameter combination is used for springback compensation in the finite element software.And then the actual model verification is performed according to the compensated surface.After that,the point cloud data of the test module is collected by the Blu-ray scanner,and the whole surface springback data is obtained by comparison with the original model;then the full model surface springback compensation is performed in Think-Design software according to the amount of springback.Then the test data after trial production showed the feasibility of the springback compensation based on Blu-ray scanning.