Modeling and vibration analysis of wind power turbine blades

A wind power turbine blade is modeled as a rotating beam with flapping angles and setting angles. Based on the Bernoulli Euler beam theory, without considering the axial extension deformation and the Coriolis forces effect, the coupled governing differential equations and the associated boundary conditions are derived by using Hamilton's principle. It is shown that if the geometric and material properties of the beam are in polynomial forms, then the exact solution for the problem can be obtained. Finally, the influences of the flapping angle and other physic parameters on the natural frequencies are investigated.