Analysis of the Capabilities of a Hyperbolic Constitutive Equation for Al-5083 Superplastic Aluminium Alloy

This paper describes the application of a hyperbolic, mechanisms-based constitutive equation set, modified to incorporate the effect of cavitation, to the prediction of the superplastic behaviour of a commercial Al-5083 superplastic aluminium alloy. The development of an algorithm for multi-stage identification of the complex set of constitutive parameters is presented and this approach is applied to characterise the constitutive behaviour of the Al-5083 at 500 degrees C, based on constant strain-rate tensile test data. A large deformation, multiaxial formulation of the constitutive equation set is implemented and applied to finite element modelling of a bulge test forming process to characterise the cavitation evolution behaviour in the bulge test for different back pressure conditions.