Comparison of beam theories for characterisation of a NREL wind turbine blade flap-wise vibration

The harsh weather conditions offshore wind turbine blades are working under have necessitated the need for a more effective approach detecting their failures. Dynamic characteristics e.g., vibration, carry useful information related to structural health. Critical analysis of blade’s free vibration represents one fundamental steps assessing dynamics. When rotating blade deflects, either in plane rotation or perpendicular it, centrifugal force exerts inertia along span, which increases natural frequencies compared with stationary ones. However, influence different parameters on flap-wise vibrations is not very well understood. In this paper, effects such dynamic National Renewable Energy Laboratory (NREL) 5-MW investigated using beam theories. examined models been used determine and mode shapes turbine. Results demonstrate that increasing angular velocity significantly impacts shapes. rotary found responses studied blades. Moreover, hub radius, pre-cone pitch angles less frequencies. Mode shape comparisons were also carried out MSF (modal scale factor) MAC assurance criteria). Compared other methods, Bernoulli’s based algorithms produce accurate results.