A new version of a rumpling predictive model in thermal barrier coatings

In many cases the modelling of rumpling evolutions appears as a necessary step in the development of a TBC life prediction methodology. The analytical model initiated by Balint and Hutchinson (2005) is further developed and improved, incorporating two new possibilities: 1. In addition to the 2D roughness description (with a single cosine model of the undulation), a 3D undulation shape is now available (a double cosine model), following a similar approach; 2. Both the 2D and the 3D undulation models are modified in order to allow any kind of thermomechanical cyclic loading applied by the substrate, with different maximum temperatures, including the possibility of oxidation, associated growth strains and oxide yielding during the temperature transients. The successive modifications in the model are evaluated by successively comparing the rumpling responses at four maximum temperatures. A parametric analysis reveals the significant role of the initial undulation geometry on the influence of several material factors like the bond coat creep resistance or the presence or not of the martensitic transformation during the temperature cycle. Moreover the initial geometry also greatly affects the difference of rumpling predicted under cyclic oxidation and isothermal oxidation. •An analytical rumpling model is extended to other geometrical and loading conditions.•The new model is now performing any kind of strain–temperature cyclic conditions.•A parametric study reveals additional capabilities in terms of initial geometry parameters.•Effects of oxide yield limit, martensitic transformation and bond coat creep are studied.