Study On The Influence Factors Of Hydroforming Of Y-shaped Tube And Thickness Distribution Optimization

The application of Y-shaped tube is very extensive,and the demand for lightweight of plastic-formed parts is increasing in key manufacturing fields such as aerospace and military.Therefore,it is necessary to study the hydroforming of aluminum alloy Y-shaped tube.According to the 5A02 aluminum alloy Y-shaped tube studied in this paper,based on a large number of finite element simulations and experiments,the hydroforming process under various process conditions was studied and qualified parts were produced.The effects of various factors on forming quality of Y-shaped tube were studied,and the better process parameters were determined.The thickness distribution of the formed Y-shaped tube is optimized by new tube cutting method and orthogonal test.The finite element model was established and material performance parameters and boundary conditions were set.The finite element software was used to simulate the hydroforming process of Y-shaped tube.The principle and forming process of hydroforming equipment were briefly introduced.The experimental mold was designed and the hydroforming experiments of Y-shaped tube was carried out.The finite element simulation and experimental verification show that Y-shaped tube will have wrinkles,insufficient formation and fracture defects when forming in different pressure paths.The strain state of Y-shaped tube under different pressure forming is analyzed.In simulation,thickness distribution of the Y-shaped tube at different positions and key points is in good agreement with the experimental results.Finally,the pressure loading path with better forming quality is obtained.Based on a better pressure loading path,the effect of different feeding ratios on hydroforming of Y-shaped tube were studied.The thickness distribution of the Y-shaped tube was analyzed and compared with the simulation results.Simulation and experiment show that the feed ratio is very important for its forming,and a better feed ratio range for Y-shaped tube forming is obtained.Different lubrication conditions were set up in the simulation and experiment.The influence of friction coefficient on the hydroforming of Y-shaped tube was studied.The thickness distribution of the formed parts and height of the branch tube and forming quality under different friction conditions were analyzed,indicating that different lubrication conditions has an important influence for the hydroforming of Y-shaped tube.The lubrication method which is most advantageous for the formation of Y-shaped tube was selected.The thickness distribution and forming quality of the Y-shaped tube formed by new tube blank cutting method were studied,which indicated that the new tube cutting method had a better effect on thickness distribution optimization of the Y-shaped tube forming.The loading path of formed Y-shaped tube was optimized by orthogonal test and a better thickness distribution was obtained.The forming of the Y-shaped tube was simulated by new tube blank cutting method combined with optimized loading path of the orthogonal test,and the better part quality and thickness distribution were obtained.The research obtained the optimized process parameters and a Y-shaped tube with better thickness distribution.