Minimum Diameter of Optimally Located Damping Wire to Maximize the Fundamental Frequencies of Rotating Blade Using Timoshenko Beam Theory

Abstract

In this study, the optimum position and minimum diameter of damping wire were investigated to maximize the fundamental frequencies of a rotating blade. The blade was modeled as an isotropic, homogenous and constant cross-sectional cantilever rotating beam. The damping wire was modeled as an intermediate elastic support. In most rotating-beam applications, such as turbine blades, the slenderness ratio is low; therefore, Timoshenko beam theory was selected to analyze the model. The optimal position and minimum stiffness of elastic support were determined to maximize the natural frequencies of the beam using the finite element method. Minimum diameter of the damping wire was calculated by determining the minimum stiffness. Parameter sensitivity analysis showed that the angular velocity of the blade has no remarkable effect on the optimal position and minimum diameter of damping wire.