Fracture of functionally graded thermal barrier coating on a homogeneous substrate: Models, methods, analysis

Abstract

Fracture of functionally graded thermal barrier coatings on a homogeneous semi-infinite substrate (FGC/H) is studied under the influence of thermal loadings. A mathematical model for the FGC/H with pre-existing systems of cracks is presented in point of view of the formulation of the boundary conditions and assumptions, and afterwards the integral equations. Methods for solving the problem are described, and then demonstrated for some special cases of the arrangement of cracks. The effect of geometry (the thickness of the coating and location - orientation of multiple cracks) and inhomogeneity parameters of FGCs on the main fracture characteristics of the material is analyzed. The study can be used to improve the thermal fracture resistance of FGC/H systems.