| The use of high strength aluminum alloy materials to manufacture the auto-body panels is one of the automotive light-weighting ways.However,the aluminum alloy auto-body panels manufactured by adopting the traditional stamping technology easily produce some defects,such as the wrinkle,fracture and scratch,resulting in the low rate of finished products.The hydroforming technology developed in recent years is widely applied to aerospace industry area due to the low processing cost of forming die,high forming limit,high precision and better surface quality.So,it has the great engineering significance to explore the application of hydroforming technology in the manufacturing of high strength aluminum alloy auto-body panels.The 3D modeling software CATIA and the finite element analysis software DYNAFORM are used together in this paper.A reasonable finite element mechanical model is established and the hydroforming processes of aluminum alloy sheet parts with large complex curved surface are simulated numerically.The defects generation mechanism in the hydroforming process of complex sheet part is investigated,and the distribution of stress and strain and the thickness variation trend under different process parameter conditions are mainly analyzed.The key parameters applied to the part tests are confirmed.The experiments of hydroforming of aluminum alloy auto-body panels with large complex curved surface are carried out according to the simulation results.The results show that the reasonable clearance between the blank holder and the die and the pressure loading path can effectively control the wrinkle and fracture of high strength aluminum alloy auto-body panels.The spring back is reduced and the qualified rate of finished products is greatly improved.Meanwhile,the numerical simulation can provide reference for the practical process. |
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