SIMULATION ANALYSIS ON THE EFFECT OF LOCAL DAMAGE OF BLADE ON STATIC AND DYNAMIC CHARACTERISTICS FOR LARGE HORIZONTAL AXIS WIND TURBINE

Based on parametric models, the static and dynamic characteristics of a wind turbine are studied. And the effects of local damage of blade on static and dynamic characteristics for a cantilever blade and a wind turbine are analyzed. The relationship between the local damage of blade and these characteristics is revealed. The parametric model of MW-level composite horizontal axis wind turbine blade is established with APDL language in ANSYS environment. The blades, hub, tower and other parts are combined to obtain a finite element model of a wind turbine using public geometric elements, connecting elements and coupling degrees of freedom. The static responses of wind turbines with and without local damaged blades in the upwind position are calculated under the coupling effect of gravity, centrifugal force and wind pressure. The dynamic strain responses in the normal and damaged conditions of blades are compared for a cantilever blade and the blade installed in a wind turbine. The results indicate that the dynamic strain response of the cantilever blade in a rotor plane decreases with the increasing of damage on the upwind surface. For the blade in wind turbine, the dynamic strain response increases in the vertical direction of the rotor plane. The research is significant for on-line damage monitoring of large horizontal axis wind turbine blade.