The present study aimed at developing an aeroelastic method of a wind turbine and highlighting the influences of aeroelasticity on both the aerodynamic and the structural performances. System's governing equations considering the aeroelastic effects of large scale wind turbines are derived by coupling a multibody method with a free vortex wake (FVW) method. The resulting differential-algebraic equations (DAE) are transformed to algebraic equations whose Jacobian matrices are difficult to be calculated. Based on an inverse Broyden-Fletcher-Goldfarb-Shanno (BFGS) approach, a quasi-Newton method with a suitable linear search is developed and used to solve those nonlinear equations, thus a new aeroelastic method without Jacobian matrices calculation is proposed. The time domain aeroelastic responses of the NH1500 1.5-MW wind turbine are obtained. The simulation results indicate that aeroelasticity of a blade has significant effects on the wake geometries and structural responses. Flexibility of the tower can cause more violent fluctuations for the power and loads compared with the results of a blade, which can considerably affect the blade fatigue life design. (C) 2017 Elsevier Ltd. All rights reserved.