Experimental and numerical investigation of mixed-mode fatigue crack growth in nickel-based superalloy at high temperature

Fatigue cracking is one of the most common damage modes of aeroengine hot-end components, usually subjected to mixed-mode cracking. In this study, mixed-mode fatigue crack growth experiments at 550 ? are carried out using compact tension shear specimens made of nickel-based superalloy GH4169. Adaptive finite element method was used to verify several models at high temperature. The accuracy of angle dependent models was higher at 550 C, and the rate of da/dN increased and decreased twice with crack propagating, which is different from room temperature (20-25 C). This research could provide a basis for lifespan prediction of aeroengine hot -end components.

Automated summary

This study investigates the fatigue cracking of aeroengine hot-end components, particularly the mixed-mode cracking at high temperature. Experimental tests and adaptive finite element method are used to verify the accuracy of different models. The findings show that the angle dependent models have better accuracy at 550℃, and the crack propagation rate exhibits a different pattern compared to that at room temperature.