The determination of material parameters from superplastic inflation tests

A procedure for determining parameters in a selected material model from a superplastic blow-forming test is presented. Emphasis is placed on the relative ease of the procedure and the lower cost of the test equipment required compared to the more involved strain-rate-controlled tensile tests. Analytical solutions are derived to correlate the true stresses and true strain rates from the experimental measurements of the inflation height of a hemispherical dome. Several material models are chosen to fit the stress-strain rate data obtained from the proposed procedures. The material models, together with the associated parameters, are implemented as user's sub-routines for the commmercial finite-element program, ABAQUS. Verification of the proposed approach is carried out by comparing the numerical solutions obtained from the program with the experimental results.