A rotor aeroelastic model with elastic blade and rigid trailing edge flap and its load calculation method were developed. The inertial forces and aerodynamic forces of flap were described as generalized mass and generalized forces. The aerodynamic forces of the common airfoil were calculated with the unsteady/dynamic stall model

and those of the flapped airfoil were got from a coupled aerodynamic model corrected with experimental data. The nonlinear elastic deformation was considered by a large deformation blade model. The force integration method was used to predict the vibratory structural loads. The predicted results and the test results were compared to verify the aeroelastic model and the load calculation method. The results show the accuracy of the blade structure model is quite high. Vibratory loads of rotor can be calculated well with the aeroelastic model

the average error of flapwise moment is 9.1%. Prediction in the vibratory loads of blade with flap motion is implemented with corrected flapped airfoil aerodynamic model.