Abstract

This worksheet is concerned with the linear and nonlinear theory of viscoplasticity. For example, in the following the rate-dependent deformation of a Fe-0.05 weight percent carbon steel at temperatures in excess of a homologous temperature of 0.5 has been discussed in coparison with suitable experiments.

   In order to describe the tensile tests at elevated temperatures, a viscoplastic constitutive eqution with three parametrs has been proposed. These parameters can be determined by using the LEVENBERG-MARQUARDT algorithm.

Keywords:  linear and nomlinear viscoplasticity; tensile tests at elevated temperature; viscoplastic constitutive equation; parameter identification; L-one and L-two error norms