Dynamic Coupling Analysis on Thermo–Chemo–Mechanical Field and Fluid–Structure Interaction for Aero-Engine Turbine Blade with Functional Gradient Thermal Barrier Coatings

In this study, an extended layerwise/solid-element (XLW/SE) method is developed for the thermo–chemo–mechanical (TCM) coupling problem of an aero-engine turbine blade with thermal barrier coatings (TBCs). The method consists of two parts, the extended layerwise (XLW) method and the three-dimensional (3D) solid-element (SE) method, which are adopted to formulate the governing equations of TBCs and substrate, respectively. Then, according to the compatibility conditions of displacement, temperature, concentration and internal force equilibrium at the TBCs/substrate interface, the governing equation of the final blade structure is assembled. Through a time integration, the dynamic responses of displacement, temperature and concentration can be calculated. In addition, the fluid–structure coupling analysis is conducted by using COMSOL. The nonuniform thermal load is imported into the XLW/SE method to calculate the mechanical response of blade structure. Finally, the corresponding computing program is compiled with C++. In numerical examples, the TCM coupling analysis is conducted on the blade structure with and without interfacial debonding and delamination damages. To validate the effectiveness of the proposed method, the dynamic TCM responses of the XLW/SE model is compared with those of a 3D elastic model generated by COMSOL, which shows that the two models are in good agreement.