Numerical and Experimental Investigation of Friction Damping in Shrouded Blades Available to Purchase

The blade is a critical turbine engine component with a high risk of high-cycle fatigue (HCF). Shrouded blades are often employed to reduce this vibration. However, the nonlinearity of contact surfaces makes it challenging to accurately predict its amplitude–frequency curves as a function of the loading magnitude. In this study, an economical experimental setup was designed, which requires only two blades to investigate the dynamic characteristics of shrouded blades. A novel method was adapted to measure the contact force and friction coefficient of the shrouds. Sinusoidal excitations were executed, and amplitude–frequency curves were recorded. Subsequently, the study established a relationship between resonant frequency to vibrational stress using these amplitude–frequency curves. Additionally, the experiment was simulated by the harmonic balance method (HBM). A hysteresis spring contact model was adapted to simulate the contact of the shrouds. Vibrational stress, resonant frequency, and damping ratio were computed based on the displacement outcomes from the HBM simulation. The consistency between the obtained simulation outcomes and experimental results was found to be satisfactory, indicating that the proposed approach effectively captured the complex behavior of the shrouded blades.