Three-dimensional modeling and simulation of superplastic forming

The computational details of a viscoplastic finite element analysis of three-dimensional superplastic forming (SPF) are discussed in this paper. Two typical superplastic forming shapes, conical bulging and rectangle box bulging, were analyzed and the experiment of conical bulging was performed to verify the numerical simulation. The inverse identification of superplastic material parameters incorporating the finite element method and an optimization technique was developed and an activity rule was proposed for effective selection of measurement locations in the experiment. Based on the numerical modeling, the influence of many factors such as the frictional coefficient, strain rate sensitivity and strain rate on the thickness distribution was studied and some useful conclusions were drawn.