Mechanism Research And Optimization Of Stamping Forging Process For U-shape Component With Bionic Element

In recent years,due to the energy crisis and environmental problems prominently,the automotive lightweight process is growing tension.Therefore,the designers of major automotive enterprises have added some bionic elements in the body structure to reduce the weight of the car and improve the body’s strength and rigidity,and ensure the safety at the same time.In the new body structure of Audi A8,key parts applied joined rib type structure with imitation birds inside of bones in the inner surface for the first time to improve the crashworthiness of car body.Because of the complicated structure,if this kind of parts take cast process to produce,there will cause many problems,such as mechanical properties decrease and weight increase.On the contrary,plastic forming can avoid these problems largely,however there were little research on this aspect.In this paper,a stamping forging forming process is proposed to complete the bionic structure of U-shape single element’s deformation,and mechanical analysis and numerical simulation method is used to analyze the characters and forming defects of this process.According to the analysis result,a construction process optimization method based on intelligent optimization algorithms is investigated.The main jobs can be shown as follows:(1)Design of the bionic structure U-shaped element forming process.According to the structural characteristics and forming difficulty of U-shape element with bionic structure,stamping forging forming process is proposed,and some preliminary analysis to forming defects like unfulfilled top area of ribs and the bottom dimple should be done.(2)Mechanical analysis on piece in U-shaped element stamping forging forming process.Based on the deformation characteristics of sheet metal during the forming process,the piece is divided into several regions,and analyze the stress of each region,to establish a complete mechanical analysis model and discusses mechanics of dimple to determine the main factors that influence the forming quality(3)On the base of mechanical analysis results,the finite element software Deform-2D is applied to simulate the forming process,and explore the rules of how the parameters affect the component’s forming quality as well as the formation of forming defects,finally to ensure the roughly range of parameter values(4)Establish optimization method via GA-RVM model to optimize parameters of forming process.Variables and targets are derived from analysis above to build process optimization design method based on GA-RVM model.Genetic algorithm is chosen to optimize the width parameter which influence on accuracy of RVM prediction model,then applied Genetic algorithm again through the high precision model to optimize processing parameters that are finally validated by numerical simulation.The mechanism and regulation of U-shape elements with bionic structure and optimization design method proposed in this paper have great universality and availability,which can offer practical production of this kind of components some guidance and reference.