Micromechanical modeling of crack propagation in TBC systems

Abstract

In this research, actual microstructures of the TBC taken by scanning electron microscope (SEM) were utilized as the representative volume elements (RVEs) in the computational model. Failure mode of the representative volume was simulated as thermal stress localization during thermal cycle. Computations were done to quantitatively assess the effects of thermal and mechanical properties of the TBC constituents as well as the presence of TGO on the macroscopic mechanical response of the TBC. Comparisons of computed results with experiments verified that, the computational method can successfully predict residual stress and crack initiation mode of the studied thermal barrier coatings.