Modelling the high temperature behaviour of TBCs using sequentially coupled microstructural-mechanical FE analyses

Thermal barrier coatings provide a means of thermal insulation of gas turbine components exposed to elevated temperatures. They undergo severe microstructural changes and material degradation, which have been implemented in this work by means of a sequentially coupled microstructural mechanical calculation that made use of a self-consistent constitutive model within finite element calculations. Analyses for different temperatures and bond coat compositions were run, which reproduced the trends reported in previous research and identified the accumulation of high out-of-plane tensile stresses within the alumina layer as an additional phenomenon that could drive high temperature crack nucleation.