Simulation Analysis Of Outer Sheet Forming Of Automobile Engine Cover Based On Hydroforming Technology

Sheet hydroforming as an advanced flexible forming technology,there has many advantages by comparing with the traditional sheet forming,including: forming parts with good quality,forming process less,low cost,short cycle,saving materials.At present,the sheet hydroforming is widely used in the manufacture of key components such as aviation,aerospace,automobile and so on.It has important practical significant for the research of sheet forming technology and industrial production.Sheet hydroforming technology has become the focus of people’s research.Therefore,this paper combine the way of theory,experiment and simulation,based on the shape of the hydroforming car hood outer plate simulation analysis.In order to study the hydroforming rule of the outer surface of the automobile hood,Firstly,this paper summarizes and deduces the theoretical knowledge about sheet hydroforming,including the plate stress analysis,the material yield theory,the equilibrium equation,the blank holder force and the liquid chamber pressure.Which will lay the theoretical foundation for the experimental analysis,finite element simulation analysis and data processing of subsequent plate hydroforming.Secondly,due to the conditions of experimental equipment,large-scale mold development and processing costs and other conditions,this paper will use a similar structure of simple aluminum alloy to carry out hydroorming research.The structural parts to be formed in the experiment have the same structural features as the outer cover of the car hood,such as forming depth,small fillet radius,large deformation gradient and so on.Finally,summarizes the forming conclusion of the simple aluminum alloy based on the hydroforming technology,and carries out the simulation analysis of the outer shape of the car hood.In order to study the forming rule of the sheet of simple aluminum alloy,the hydroforming experiment equipment of aluminum alloy sheet was designed and built.The simple sheet part was used to carry out the forming experiment.Through the analysis of based on the sheet forming technology,Hydroforming characteristics.In order to further understand the forming rule,the finite element software is used to simulate the simple aluminum alloy sheet.The comparison between the experimental results and the simulation analysis verifies the correctness of the finite element model establishment and simulation calculation.Based on the experiment and simulation results of the simple aluminum alloy sheet,the finite element simulation analysis of the outer cover of the engine hood is carried out to study the variation of the stress and strain of the sheet during the process of hydroforming,and the outer shell of the hood is studied during the forming process blanking force,blank holder force loading path,liquid chamber pressure and friction coefficient and other key process parameters on the quality of forming parts.The greater the blanket force and friction coefficient,the more easily the rupture of the sheet during the forming process,the size of the liquid chamber pressure and the different blank holder force loading path directly affect whether the sheet can be formed and so on.Through the finite element simulation analysis of the outer cover of the automobile hood,the high quality sheet parts and the optimal process parameters are obtained.The simulation results are optimized to lay the foundation for the hydroforming experiment and the determination of the process parameters good foundation.The research of this subject not only serves the practical production of the hydroforming of the outer hood of the automobile hood,but also provides reference for the experimental and practical production of other parts.