Abstract:
To address the challenge of evaluating aeroservoelastic (ASE) characteristics in blended-wing-body (BWB) aircraft, we establish a reduced-order nonlinear servo-elastic modeling approach based on Craig-Bampton component-mode synthesis technique, considering the effect of control surface freeplay nonlinearity of actual aircrafts. To accurately characterize the servo-elastic behavior of aircraft with elevon freeplay nonlinearity, the comprehensive experimental investigations are performed, including actuator-aileron system transfer function identification, elevon freeplay measurement, open-loop frequency response analysis, and closed-loop stability assessment. A correction approach of servo-elastic dynamic model is developed specially for BWB configurations with elevon freeplay. On this basis, the simulation analysis is conducted on the modified servo-elastic dynamic model of the BWB aircraft. The obtained results show a good consistency between numerical simulation and experimental testing, which indicate that the proposed nonlinear servo-elastic modeling and correction method can accurately capture physical characteristics of aircrafts. The present framework provides an effective approach for accurately predicting the aeroservoelastic characteristics in aircraft with control surface freeplay nonlinearity.