Thermo-electro-mechanical numerical modeling with an analytical approximation of coupled thermal fatigue failure process of corset samples from single-crystal nickel-based superalloys

The results of computations of the thermal and stress-strain state of single-crystal corset specimens subjected to the action of periodic electric current, leading to variable inhomogeneous heating and subsequent thermal fatigue failure, are presented. An analytic approximation was introduced for the process of nonstationary heating of corset sample and a comparation of modeling results with experimental data and analytic model was evaluated which showed a good correlation with experimental data. The influence of maximum value and range of temperature and also influence of a delay time at the maximum temperature on the number of cycles before the macrocrack formation were investigated. Also an analytic approximation was considered of a delay influence and comparison of the computational results and analytic formulaes with the experimental data for various single-crystal nickel-based superalloys showed a good accuracy.