Finite Element Simulation for Superplastic Forming Process of Aluminium 5083

摘要

Finite element (FE) simulation of superplastic forming process applied on superplastic alloy Al 5083 at 510℃ was conducted by using commercial FE codes LS-DYNA and ABAQUS. Dynamic explicit solution procedure was applied under consideration of the cost of calculation time and simplicity of the surface contact. First, the material parameters were determined from uniaxial tensile tests at constant strain rates. The strain rate was maintained constant by adjusting continuously the cross head velocity according to its exponential relationship with the time. The flow stress curves from FE analysis were then verified. Bulging process of a thin sheet was simulated with pressure controls. The sheet was discretized into shell elements in radial meshing. FE analysis generated results: pressure-time curves, history curves of the ratio between the maximum and the pre-determined strain rate, history curves of the dome height and the thickness distribution. The effects of m value and friction coefficient were investigated. In addition, a comparison of the results with static implicit approach was performed.