Vibration Characteristics of Mistuned Blisk with Chordwise Variable Thickness Blades Subjected to Aerodynamic Prestress

Abstract

In this paper, the influence of aerodynamic prestress on vibration characteristics of mistuned blisk is investigated by comparative study considering one-way fluid–structure interaction. It is found that the aerodynamic prestress changes twisted angle of the blade, increases natural frequencies of the mistuned blisk and affects the sensitivity of natural frequency to rotational velocity. To facilitate the mechanism study of these phenomena, a simplified blade model with chordwise variable thickness is established. The effects of Young’s modulus, rotational velocity and pre-twisted angle on natural frequency are investigated by the first-order shear deformation plate theory and Chebyshev–Ritz method. The results show that the natural frequency of the blade is positively correlated with the rotational velocity and pre-twisted angle. For different twisted angles, the same rotational velocity change can cause different natural frequency increments. In addition, the aerodynamic prestress can suppress the effect of Young’s modulus mistuning on natural frequency.