Numerical results achieved with an inverse computational method for determining the constitutive parameters usina the hot torsion test results

It was demonstrated in a previous paper that to obtain a unique set of parameters for a constitutive relationship from the hot torsion test, two separate objective or error functions must be considered. They are based on the load-displacement and load-displacement rate data respectively. The algorithm described earlier, has been implemented in a rigid viscoplastic FE code. The best set of the constitutive parameters that minimizes the objective functions is determined by using an optimization scheme. To demonstrate the predictive capabilities of the analytical approximation described in the previous part and to simulate the problem of identification of material parameters, a set of pseudo-experimental load-displacement/displacement rate data has been used for calculating the objective functions. The results confirm the inadequacy of using only the load-displacement results for the identification of the constitutive parameters from the hot torsion results. This is in agreement with the theoretical results in the previous paper. It is shown subsequently that the newly proposed inverse computational method can be used successfully to determine a unique set of the constitutive parameters.