Nonlinear Thermo-Elastic-Plastic and Creep Analysis by the Finite-Element Method

Consistent with a Lagrangian displacement formulation, an incremental constitutive relation for uncoupled thermoelastic-plastic and creep deformations is presented. The nonisothermal von Mises yield function and its associated flow rule are utilized, together with both isotropic and kinematic hardening rules. Steady-state creep deformations are considered using Norton-Odqvist's power law. This development is particularly applicable to the nonlinear finite element analysis of three-dimensional structures with timeand temperature-dependent material properties. Using a nonlinear general-purpose computer program which has been developed on the basis of this formulation, a number of numerical examples are solved and the results compared with the closed-form solutions.