Flapwise Bending Vibration Analysis of Rotating Tapered Rayleigh Beams for the Application of Offshore Wind Turbine Blades

The flapwise bending vibrational equations of tapered Rayleigh beam are derived based on Hamilton’s principle. The corresponding vibrational characteristics of rotating tapered Rayleigh beams are investigated via variational iteration method (VIM). Natural frequencies and corresponding mode shapes are examined under various rotation speed, taper ratio and slenderness ratio focusing on two types of tapered beam. The convergence of VIM is examined as part of the paper. Validation of VIM solution is made by referring to results available in other literature and corresponding results show that VIM is capable of yielding precise results in a very efficient way.