Simulation of Thermomechanical Fatigue of Structured Materials

Technology of low-cycle fatigue simulation under nonisothermal loading was developed. It is based on the two models: threeparametric model of cyclic stress-strain curve which determines set of thermomechanical surfaces of plastic strain and damage model. Based on experimental results under isothermal cyclic loading thermomechanical surfaces of cyclic loading were created. Parameters of cyclic stress- strain curves were determined by the processing of the experimental data by the optimization techniques. Parameters of damage model were determined by the least squares method. A program for simulation of specimen tests under nonisothermal cyclic loading was developed for the verification of the proposed models under various types of cyclic loading. Influence of creep and creep rupture strength was taken into account in the simulation of nonisothermal cyclic stress- strain curves and low cycle fatigue respectively. Mathematical simulation of the various experiments in literature of thermomechanical fatigue was carried out for the performing of efficiency of the proposed models and programs.