Analysis of Vibration Characteristics of Rotating Blades

This study is mainly aimed at aircraft propeller blades. In this paper, a propeller blade model is established by ANSYS software, and its vibration characteristics are studied by fluid–structure coupling simulation and modal analysis. In modal analysis, the ordinary modal analysis was carried out on the steel blade. The softening effect caused by the change of blade speed is also studied. Modal analysis shows that rotational softening reduces blade stiffness and natural frequencies. Aerodynamic force and centrifugal force are introduced to conduct fluid–structure coupling simulation and prestressed modal analysis of the blades, and study the influence of these forces on the modal frequency of the blades. After centrifugal force loading, the first natural frequency increases significantly. With the change of blade speed, the frequency of each order of blade also has different changes. The natural frequencies of each order of forward precession increase with the increase of blade speed, and the natural frequencies of each order of reverse precession decrease with the increase of blade speed. The first-order mode critical speed of the rotating blade increases, and the second-order mode speed decreases. After aerodynamic loading, the frequencies of the blades do not change much, and the critical velocities of the first and second order modes of the rotating blades increase.