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Gas turbine engines undergo very harsh operating environmental conditions, and this leads to various issues related to components materials strength limitations, degradation, cracking, and other durability problems. Under such circumstances, a robust material design is required to prevent these critical components from failing in service and preventing catastrophic events from taking place. The robust design must enhance component durability, which could be degraded due to material processing defects, variability in material properties, in-service loads, and operating environment. To encounter and manage these durability issues, materials scientists and engineers that are involved in this field along with engine makers are continuously working on developing protective materials to alleviate and increase materials damage tolerance and prevent components failure. Ceramic matrix composites (CMC) are now materials of choice for gas turbine engine design and manufacturing. The CMC has a good capability in operating at high temperatures up to 1500 °C which is within the norm of gas turbine engine operation and it is much lighter compared to metals. Good impact resistance and stability at high operating temperatures make the silicon carbide (SiC) ceramic matrix composite system a desirable option for jet engines [1]. However, CMC’s when they undergo the degradation process that typically includes coating interface oxidation as opposed to a moisture-induced matrix which is generally seen at a higher temperature. Additionally, other factors such as residual stresses, coating process-related flaws, and casting conditions may influence the degradation of their mechanical properties. These durability considerations are being addressed by introducing a highly specialized form of environmental barrier coating (EBC) that is being developed and explored in particular for hightemperature applications greater than 1100 °C [2]. In this paper, a CMC substrate is being evaluated for failure under supportive protection of EBC coatings. The primary aim is to identify the crack propagation phenomenon, the sequence of failure of the EBC and assess the life the CMC substrate. An analytical simulation applying the extended finite element method (XFEM) in ABAQUS software [3] is used to perform this analyses. Analytical results obtained are discussed and checked against test data.
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