Finite element simulation for superplastic forming using a non-Newtonian viscous thick section element

Superplastic forming (SPF) is becoming an increasingly important manufacturing process in the aerospace and automotive industries. Finite element simulation is an essential tool for the specification of process parameters. Initially applied only to thin sheet materials, SPF is now increasingly used to form thick section components. In this paper, a curved thick shell element, including membrane, bending and transverse shear stiffness, is combined with a non-Newtonian viscous flow material model to facilitate the modelling of thick sheet problems. The element is suitable for both thick and thin sheet down to all thicknesses used in practice. Good agreement is achieved when experimental results from industry and numerical results from the literature are compared with results obtained using the new formulation.