| With the progress of society and the development of industry,cars have gradually become people’s daily necessities,and people’s requirements for cars are not only satisfied with the simple concept of means of transportation and transportation,which endows the element of automobile economy.Lightweight is an important way to reduce fuel consumption and reduce vehicle costs.Lightweight technology reduces vehicle weight to achieve energy and emission reduction goals by optimizing materials and body design based on vehicle performance that is unaffected by vehicle rigidity and safety performance.According to relevant statistics,for reducing every 100 kilograms of car weight,greenhouse gas emissions can be reduced by 5 grams per kilogram.We can see that the development of lightweight technologies for automobiles is in line with the current requirements for energy saving and emission reduction in automobile development.Currently,there is a lot of research on weight reduction technology,and the use of high-strength steel is a common weight reduction method.This paper presents an approximate model based on Isight software and multi-objective genetic optimization combined with design of experiments to optimize the formability of high-strength steel based on geometric properties and optimize the design of structural parameters.Choose to build an optimization algorithm.The combination of optimized parameters improves the formability of the part.The main research contents are as follows.First,According to the classification method of auto parts,this article divides the typical auto parts into five basic types based on the performance of the parts in the body structure and the actual process of part design and production,and selects one of the typical parts for finite element analysis.Through stamping simulation analysis and multi-objective optimization,the effects of structural and process parameters on the formability of such parts were found and the results obtained are of certain practical importance of the manufacture and selection of such parts.Secend,Aiming at advanced high-strength steel parts of automobiles,we use numerical simulation technology and finite element theory to simulate the forming process of the right front longitudinal beam.First,we will introduce the basic theory of finite elements related to sheet metal forming,and then propose a formability evaluation index for body parts of advanced high-strength steel.Research stamping molding theory and part fillets.Effect of four structural parameters of radius,component sidewall gradient,component height,number of stiffener,and two process parameters of drawbead coefficient and blank holder force on formability of high-strength steel components.Through analysis and summarization,we have gained some experience in the structural design and manufacture of high-strength steel body parts.Third,in view of the shortcomings of the existing optimization methods,a research method of part forming performance analysis and optimization design for the fluctuation of structural parameters and process parameters is proposed.Then,the concept and theoretical advantages of experimental design and multi-objective optimization are introduced,and detailed The calculation process of the experimental design is described.Fourth,select the maximum thinning rate,maximum wrinkle factor and maximum springback in the forming performance evaluation index as output parameters,and 4 structural parameters and blank holders:bending radius,facade inclination angle,part height and the number of ribs The two process parameters of force and drawbead coefficient are used as optimization parameters,a six-factor three-level Box-Behnken test design is established,and based on the test results,build a response surface approximation model between the molding performance evaluation index and the optimization parameters.Based on the constructed approximation model and multi-objective optimization theory,the NCGA algorithm is used to optimize the relevant parameters that affect the formability of high-strength steel parts.The optimal combination of parameters is obtained as part height h=50mm and fillet radius.R=llmm,side wall slope θ=6°,number of stiffeners n=3,drawbead coefficient,u=0.3,blank holder force F=570KN.According to the optimized parameter combination,the part structure and stamping process are modified,and the optimized parts have good formability through experiments,and the risk of cracks,wrinkles,and excessive springback defects are greatly reduced. |
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