弹性飞翼飞机建模方法

Modeling for Flexible Flying Wings

摘要:

大展弦比无尾飞翼布局飞机的结构振动往往与刚体运动耦合在一起,而传统的刚体模型不能反映飞机的结构弹性变形。现有研究多采用基于有限元法建立的模型,变量物理意义不明确,不利于控制系统设计。文章采用两根固定于质心的悬臂梁表征飞机的结构振动特性,基于Lagrange方程,为弹性飞翼飞机建立了刚/弹性耦合的纵向运动方程,并在配平点将模型线性化,通过分析系统的特征结构,验证了结构振动与刚体运动之间的耦合关系。所建立的模型能较真实地描述弹性飞翼飞机的运动,变量物理意义明确,便于控制系统设计。

Abstract:

The structural vibration of tailless flying wings with high aspect ratio is often coupled with its rigid motion. The traditional rigid model can not reflect the structural deformation. The models used for current research are usually based on finite element method, and the physic meanings of the variables in these models are often obscure. Using two cantilever beams fixed at the center of mass of the vehicle to represent its structural vibration properties, a longitudinal model of rigid mode coupled with flexible mode based on the Lagrange’s Equation was presented in this paper. The longitudinal model was linearized at a trim point. And the relationship between structural vibration and rigid motion were analyzed as well, which in turn proved the coupled relationship we assumed before. The model we got herein could reflect the motion of flexible flying wing and was convenient to be used for the design of flight control system.