Vibration load

sound load and other factors may result in high cycle fatigue of aero-engine rotor blade. The acoustic vibration fatigue properties of aero-engine rotor blades were studied experimentally. Firstly

the effects of blade root boundary conditions on the acoustic responsiveness properties of aero-engine rotor blade were studied. Three different clamping forces were applied to three groups of rotor blades. Then sound loads were applied to each group of blades from low to high. The relationship between the acoustic responsiveness and the sound pressure under different boundary conditions was therefore got. The results showed that blade root boundary condition was an important influential factor to the blade acoustic responsiveness. Then the acoustic vibration fatigue properties of the blade were studied. Conclusions could be drawn as follows:rotor blade could be damaged under sound loads; blade frequency decrease is slightly different when applying two different vibration excitations to two rotor blades

i.e. random vibration and sinusoidal vibration. The lifespan of blade under sinusoidal excitation is much longer than under random excitation if both are at the same dynamic stress level.