Research on Springback of 5A02 Aluminum Alloy Considering Thickness Normal Stress in Hydroforming

Springback is an unavoidable problem in sheet metal forming. When the amount of sheet springback exceeds the allowable range, it becomes a forming defect. In the process of hydraulic bulging, the fluid medium acts on the surface of the sheet uniformly instead of the rigid mold, so that the material is simultaneously stressed, which makes the deformation law of the material different from that of the sheet in the traditional rigid bulging. In this paper, the research on the springback of 5A02 aluminum alloy is carried out by taking the active hydroforming process of a typical shallow drawn rotatory body arc surface part as the research object. The theoretical analysis method is used to take the thickness normal stress into the theoretical calculation of the springback amount, and a theoretical springback amount calculation model of the three-dimensional state of stress. Numerical simulations are carried out under different loading paths with hydraulic pressure of 1, 2, 3, 10, 20 and 30 MPa. The influence and law of springback of the parts under different loading paths and different hydraulic conditions are also obtained.