Modelling of Thermal Fracture of Functionally Graded/Homogeneous Bimaterial Structures under Thermo-Mechanical Loading

Mathematical modeling of thermal fracture of functionally graded/homogeneous bimaterial structures with a system of arbitrarily located cracks is performed and based on the previously suggested theoretical approach [1-4] which used the integral equation method. It is supposed that the structure is subjected to thermal loading (a thermal flux) and mechanical loading (a tension). The properties of the functionally graded material (FGM) are described by a continuous exponential function. The main fracture characteristics (stress intensity factors and fracture angles) are presented as functions of the geometry of the problem and special inhomogeneity parameters of FGMs. Some typical crack patterns for FGM/homogeneous bimaterial structures resulting from experiments available in literature are studied in detail. Thermal fracture of actual material combinations of FGMs such as: ceramic/ceramic, e.g., TiC/SiC, MoSi2/Al2O3 and MoSi2/SiC, and also ceramic/metal FGMs, e.g., zirconia/nickel and zirconia/steel, is investigated.