The Simulation of a Unified Viscoplastic Model at Elevated Temperature

Abstract

In this paper, a Chaboche unified constitutive model has been used to describe the cyclic plasticity and viscoplasticity of Nimonic alloy 75. A non-linear optimization algorithm has been applied in numerically simulation of this alloy at elevated temperature. Optimization algorithm has facilitated a step-by-step method to obtain the initial material parameters, while a non-linear least-square approach were used to obtain the optimized material parameters. Uniaxial experiments were carried to obtain the full cyclic stress-strain and stress relaxation data at 600ï‚°C. Satisfactory results have been obtained for the simulation of the transient and steady state cyclic stress-strain and stress relaxation behavior of dwell cyclic test.