Multi-step forming simulation and experiment of swing arms for torsion beam

Numerical simulations of bending, performing, and hydroforming processes of automotive swing arms for torsion beam were conducted using finite element analysis. The process parameters such as bending radius, mandrels, loading paths, and calibration pressure were optimized in the simulation. In addition, closing force was predicted by die stress–strain analysis using the elastic finite element method. Subsequently, the bending, performing, and hydroforming experiments were performed based on the simulation results. The experimental results indicated that swing arms could be fabricated when the bending radius, calibration pressure, and closing force would be of 120 mm, 150 MPa, and 15,000 kN, respectively. Finally, swing arms with high thickness uniformity were obtained and the thickness distribution between numerical and experimental results was well consistent.