FINITE-ELEMENT STRESS-ANALYSIS FOR STEADY CREEP

Based on the virtual work principle, an energy expression on the steady creep problem for three-dimensional structures is deduced in this paper. By use of the finite element method, nonlinear algebraic equations with respect to the steady creep strain rates are obtained. These nonlinear algebraic equations are incorporated into a three-dimensional linear elastic finite element program. The strain rates and stresses of the steady creep are calculated directly by the modified Newton-Raphson iteration method with the Aitken method for accelerating convergence. This numerical scheme for analysis on the steady creep is an efficient one which can be applied to calculate accumulated creep strains and further evaluate the integrity of high temperature structures during sustained loading.