Effect of bending angle on hydroforming of curved hollow components

In order to solve the crack problem of curved hollow components during hydroforming, a front chassis frame was taken as an example and the effect of three bending angles of 0.98α, 1.0α and 1.02α(α is the axis angle of hydroformed part) on the crack defect of rectangular section part was investigated by numerical simulation and experiment. The results show that if the angles of 0.98α and 1.02α are used, the crack defect easily occurs in the superimposed area of bending lateral wall and transition zone of rectangular section. If the angle of 1.0α is used, the process can be successfully conducted. It can be seen that the non-uniform thickness of the initial tubular blank due to the thinning and thickening in the bending process and the inhomogeneous deformation due to the axis deviation are the two main reasons for the occurrence of crack defect. By controlling the bending angle, the uniform circumferential deformation of section part can be successfully achieved.