Life prediction of thermally cycled thermal barrier coatings

A finite element model based on cyclic in-plane stress range for thermal barrier coating systems was developed. This model was used to simulate thermal shock tests and predict life for Round Robin experiments conducted within the Brite-Euram project 7287. The tested samples were modelled with an elastic-visco-plastic material model. A wavy sinusoidal interface between the ceramic layer and the bond coat was introduced. The transient temperature field, and stress and strain fields caused by the temperature gradients in the different layers of specimens during thermal cycling and thermal mismatches were computed. The predicted lives of the coatings showed a reasonably good agreement with the experiment data.