Investigation On Large Height-Diameter Ratio Cylindrical Cup Forming Process By Hydrodynamic Deep Drawing Based On FEA

With the light-weight requirement of automobile, aviation and aerospace industries, aluminum-magnesium alloy, titanium alloy and other light-weight materials are widely applied. However, these materials are difficult to be formed by traditional processing method on one step since their poor plasticity and formability, especially for the parts with large height-diameter ratio.In this paper, the elastoplastic constitutive equation, the Barlat's quadratic anisotropic yield function and Hill's quadratic anisotropic yield function in the framework of basic theories for the numerical simulation of sheet metal forming are introduced. This paper also analyzes the dynamic explicit algorithm and integral stability condition, which provide theoretical support for the studies of numerical simulation of sheet metal forming.Aiming at the forming need of aluminum-magnesium alloy and other low plasticity,height-diameter ratio materials, numerical simulations of the aluminum-magnesium alloy (5A06) cylindrical cup's multi-stage deep drawing process are carried out by using large non-linear dynamic explicit analytical software ETA/Dynaform5.5 based on Finite Element Analysis(FEA). Meanwhile, the typical plastic deformed regularity of multi-stage deep drawing for cylindrical cup is analysed, the control method of wrinkle and crack defects is discussed. The effects of important technical parameters on cylindrical cup's multi-stage deep drawing formability were discussed by taking the forming limitation as research focuses.To meet the forming need of aluminum-magnesium alloy large height-diameter ratio cylindrical cup, a new forming process a new forming process is proposed, that is hydrodynamic deep drawing (HDD) with radial hydraulic pressure. The effects of loading paths of chamber pressure and radial pressure on the formability are discussed by taking the wall-thickness distribution as standard by means of numerical simulation. The effects of the parameters of sheet and mould on forming quality are analyzed. The results indicated that under the reasonable match of liquid chamber pressure and radial pressure loading paths, the HDD with radial hydraulic pressure can control crack and deforming deficiency, improve the thickness distribution uniformity, and increases the die fittingness and stiffness. It also effectively reduces the forming steps and increases the forming limitation of aluminum-magnesium alloy large height-diameter ratio cylindrical cup.