THERMOMECHANICAL ANALYSIS OF FUNCTIONALLY GRADED THERMAL BARRIER COATINGS WITH DIFFERENT MICROSTRUCTURAL SCALES

The recently developed two-dimensional version of the higher-order the ory for functionally graded materials (denoted as HOTFGM-2D in previou s communications) has been used to investigate the effects of microstr uctural architectures in graded thermal barrier coatings (TBCs) on str ess distributions in the presence of a through-thickness temperature g radient. In particular, the response of TBCs with different levels of functionally graded microstructural refinement and different arrangeme nts has been investigated, and the results for the through-thickness s tress distributions are compared with those based on the standard micr omechanical homogenization scheme. The examples presented illustrate t he shortcomings of the standard micromechanics-based approach that is applied to the analysis of functionally graded TBCs, particularly if t he presence of creep effects is included in the analysis.