Application Of Technology Of Multi-objective Optimization In Siulation Of Sheet Metal Forming

The automobile covering parts has the characteristics such as high surface quality,large size, complicated shape, etc. In view of the large covering parts, generallyrequire the drawing forming process; it is also the basis of the follow-up process. Butin the process of forming, defects such as cracking, wrinkling and the formingdeficiencies often appear. And with the increasingly competitive market environment,enterprises were required to improve the quality of stamping, at the same time, stillneed to shorten the mould manufacturing cycle.The traditional mould development generally adopts the "trial and error method",this method not only wasted a lot of human and financial resources, but only for thecovering parts that have simple shape, too dependent on the operator’s experience andskill, result in long development cycle of mold, restricting the development of mouldindustry. With the development and continuous improvement of the basic theory ofelastic-plastic mechanics and finite element method, some large mould companies areexploring more efficient mould development methods. This paper is on the basis ofpractical production of TianJin Automobile dies Limited by Share Ltd, combined withthe numerical simulation analysis technology, to explore optimization methods whichare suitable for automobile body covering parts forming process, in order to improvethe development cycle of mold and the quality of product molding, ultimately achievethe purpose of improving enterprise competitiveness.This paper mainly includes the following aspects of content:(1) Discuss the domestic and foreign research dynamic forming of auto-bodypanel, based on the numerical simulation methods and optimization technique at homeand abroad, combined with the needs of actual production projects, put forward thepurpose, significance and the technical route of this topic. At the same time, describesthe elastic-plastic finite element basis briefly;(2) Compared the advantages and disadvantages of different optimizationmethods and experimental design methods in the multi-objective optimization process,combined with the characteristics in this paper, and finally select the Super Latinmethod to carry out the experimental design, use the Polynomial response surfacemethod to construct approximate model;(3) Based on the production experience of engineering practice, summarizes the common defects and generation mechanism of forming. Summarize the knowledge,design specification and other contents of the process of sheet metal forming andtranslate the design experiences into design constraints. Meanwhile, according to therelated principles of FLD, put forward several design variables which affect thequality of stamping forming, and quantify the effect of design variables on theobjective function;(4) On the basis of the optimization principle, regarding cracking, wrinkling andinadequate deformation as evaluation functions, to optimize the primary designparameters of the process for model. Specific for: Through the CAE analysis resultsof initial mathematical model, combined with production experience, select designvariables that have larger influence on forming. Making use of super Latin squaremethod to extract samples, through the CAE simulation analysis, with the help ofMatlab obtained the corresponding response value of the samples. Constructapproximate model by the samples and response value, and verify the accuracy of theapproximate model. Contact with the initial simulation results, add the appropriateconstraints for the design variables and objective functions, solve the optimal solutionof the approximate model by using the principle of genetic algorithm. Finally comparethe optimized results and the actual results and prove the correctness of this method.This paper is a stamping engineering application issue, by using the trunk boarddevelopment work of a project in TianJin Automobile dies Limited by Share Ltd, atthe early stages of the drawing die design, using the optimization design andsimulation methods proposed in this paper, has solved the problems of surfacemodeling technology of the Parts Z501. Through the actual production process, thismethod is proved to shorten the development cycle of mold, improve the designprecision and solve the problems of complex covering parts forming is very effectiveand reliable.