Influence of heat-resistant coatings on the state of thermal stress of model of gas turbine engine blades in nonsteady heat exchange

The finite-element method was applied to calculate the thermal state and the state of stress and strain of a wedge-shaped model with a heat-resistant coating (heat shield) subjected to heat cycling by a gas stream. We analyzed the influence of the method of discretization of the section of the model and of the method of specifying the characteristics of the materials of the base and of the coating on the accuracy of the solution of the problem of thermoelasticity. We obtained data on the influence of the technological factors and of the thickness of the heat shield on the kinetics of the state of thermal stress of the material of the models. It was established that a ceramic layer changes the asymmetry of the cycle to the side of tensile stresses and shifts the maximum of the stresses into the range of lower temperatures.Translated from Problemy Prochnosti, No. 6, pp. 24–30, June, 1994.