Two modeling methods of the root insert for wind turbine blade are presented,i.e.,the local mesh optimization method(LMOM)and the global modeling method(GMM).Based on the optimized mesh of the local model for the metal contact interface,LMOM is proposed to analyze the load path and stress distribution characteristics,while GMM is used to calculate and analyze the stress distribution characteristics of the resin layer established between the bushing and composite layers of root insert.To validate the GMM,a tension test is carried out.The result successfully shows that the shear strain expresses a similar strain distribution tendency with the GMM′s results.
The Euler-Bernoulli beam model coupled with the sectional properties obtained by the variational asymptotic beam sectional analysis(VABS)method is used to construct the blade structure model.Combined the aerodynamic loads calculated by unsteady blade element momentum model with a dynamic inflow and the dynamic stall correction,the dynamics equations of blade are built.The Newmark implicit algorithm is used to solve the dynamics equations.Results of the sectional properties and blade structure model are compared with the multi-cell beam method and the ANSYS using shell elements.It is proved that the method is effective with high precision.Moreover,the effects on the aeroelastic response caused by bend-twist coupling are analyzed.Torsional direction is deflected toward the upwind direction as a result of coupling effects.The aerodynamic loads and the displacement are reduced.
