柔性翼飞行器刚柔耦合动态特性研究

针对柔性翼飞行器柔性机翼弹性运动与飞行器刚体运动具有强耦合特性，基于拉格朗日方程，建立了柔性翼飞行器动力学模型.在特征点处对动力学模型进行小扰动线性化处理，并联立非定常气动力模型，得到了状态空间形式的纵向线性运动方程.分析了机翼结构刚度对飞行器纵向稳定性的影响以及飞行器的模态耦合动态特性.研究结果表明，柔性翼飞行器的弹性自由度会对飞行器的短周期模态造成较大影响.随着飞行速度的提高，短周期模态频率增加而1阶弯曲弹性模态频率降低，当两者频率趋向一致时，飞行器会发生体自由度颤振，体自由度颤振速度要明显低于基于悬臂梁机翼模型计算得到的颤振速度. 

Analysis of Rigid-Flexible Coupling Dynamic Characteristics of Flexible Wing Aircraft

For flexible wing aircraft, the elastic motion of flexible wing and the rigid motion of aircraft were strongly coupled; a dynamic model of flexible wing aircraft was established based on the Lagrange equations. In the characteristic points, the dynamic model was linearized based on the small disturbance linearization processing. Coupled with the time-domain unsteady aerodynamic force model, the longitudinal linear equations of motion in state space form was established. The effects of wing structure stiffness on the longitudinal stability of the aircraft and the dynamic characteristics of the aircraft ware analyzed. The results show that the elastic degree of freedom of flexible wing aircraft would have a great impact on the short period mode. With the increase of flight speed, short period mode frequency will increase accordingly, while the first order bending mode frequency will decrease. When the two frequencies tend to be consistent, the body freedom flutter occurs. The body freedom flutter speed is significantly lower than that of the result based on the cantilever wing model.