Thermal fracture of functionally graded thermal barrier coatings with pre-existing edge cracks and multiple internal cracks imitating a curved interface

Abstract This work is devoted to the problem of thermal fracture a functionally graded coating on homogeneous substrate (FGC/H) with an emphasis analysis special system cracks that simulates curved interface. The FGC/H structure contains pre-existing crack in FGC, both edge (which are often seen structures) and internal cracks. stress intensity factors calculated. (Generally, Mode I II nonzero.) Then, using appropriate criterion for mixed-mode conditions, propagation direction (so-called angles) critical loads, when this initiated, determined. application criteria requires knowledge toughness near tips. Thus, it assumed as well other material properties, continuously varies through thickness coating. For multiple cracks, also important know weakest starts propagate first, initial growth. Therefore, main attention paid evaluation angles different parameters structure. Both cases semi-infinite medium imitating interface structures identical systems studied.