Accurate 3D thermal stress analysis of thermal barrier coatings

Abstract

An accurate and efficient calculation method for the thermoelastic field of thermal barrier coating structures has a great contribution to their accurate design and quality promotion. However, because of the thin coating thickness and large stress gradient in the coatings, it is too hard to guarantee the calculation accuracy especially on the interface by using the traditional commercial software. With this motivation, an accurate method for 3D thermoelastic field of thermal barrier coating structure under arbitrary heat loads is proposed in this paper. The numerical results reveal that the method has good convergence, high accuracy, and high stability. Based on this method, the effects of material parameters and coating thickness on the stress field are investigated to provide a refined guideline for the selection of coating materials. Furthermore, the optimal thickness of coating can be designed accurately by considering the interfacial failure criterion. Numerical results also reveal that the appropriate coating materials and coating thickness can largely reduce coating and interface stress. These studies indicate that the highly precise calculation method is useful for extremely fine structure design, parameter analysis and failure evaluation of the thermal barrier coating structures and enhancing their quality.