Failure assessment of braided ceramic matrix composite dovetail turbine blade under thermo-mechanical load

초록

Ceramic matrix composites (CMCs) are being incorporated as suitable materials for gas turbine components. So, the braided CMC (SiC/SiC) blade is considered in the current work. The research presents the failure analysis of fatigue due to turbine blades' loading environment. The study incorporates load and boundary conditions according to the aero engine's working environment (temperature and structural) of turbine blades. The augmented Lagrange algorithm is applied between the disc and dovetail to replicate a better connection. First, the analysis process is verified with the literature. Then, macro-scale (meters; blade with dovetail) alternate stress, damage safety ratio, and failure conditions are checked. Finally, braided level analysis is performed based on the macroscale elemental results to sense the damage at the meso-scale (millimeters; braided pattern). The results show that the damage safety factor is approximately 31 percent higher and alternative stress is roughly 24 percent lower than traditional Ti alloy. Also, the mesoscale results indicate the damage pattern and its propagation. It ensures the failure mechanism and strength reliability to explore braided CMC parts. Thus, investigating the damage conditions is helpful to the mechanical performance of turbine blades, which can provide technical support for applying braided CMCs on an aero-engine.

키워드