Nonlinear aeroelastic stability analysis of wind turbine blade with bending–bending–twist coupling

•Nonlinear aeroelastic stability analysis of wind turbine blade is investigated.•The composite thin-walled blade is integrated with bending–bending–twist coupling.•Nonlinear aeroelastic equations are reduced to ordinary equations by Galerkin method.•Resulting equations are linearized for small perturbation of the equilibrium point.•Stability is investigated by time domain response and eigenvalue analysis.

In this study, the nonlinear aeroelastic stability of wind turbine blade with bending–bending–twist coupling has been investigated for composite thin-walled structure with pretwist angle. The aerodynamic model used here is the differential dynamic stall nonlinear ONERA model. The nonlinear aeroelastic equations are reduced to ordinary equations by Galerkin method, with the aerodynamic force decomposition by strip theory. The nonlinear resulting equations are solved by a time-marching approach, and are linearized by small perturbation about the equilibrium point. The nonlinear aeroelastic stability characteristics are investigated through eigenvalue analysis, nonlinear time domain response, and linearized time domain response.