航空复合材料翼面结构气动伺服弹性剪裁

Aeroservoelastic Tailoring of Aeronautical Composite Wing Structures

本文对航空复合材料翼面结构进行了带主动控制系统、满足颤振速度及工艺尺寸要求的最小重量设计.采用亚音速偶极子格网法计算非定常气动力,用状态空间法计算翼面颤振速度,利用最佳控制理论进行最优控制设计,结构固有振动用谱变换Lanczos方法求得.机翼结构用有限元进行模拟,共采用金属及复合材料的杆元、受剪板元、正应力四边形及三角板元等,设计变量取为腹板板厚、杆元截面积及复合材料各定向铺层的厚度,目标函数取为结构重量,约束函数取为闭环颤振速度及工艺尺寸要求,优化问题用可行方向法求解,其中约束函数对设计变量的导数用差分法进行计算.文中对一个实验用机翼进行了颤振主动控制设计,对一个复合材料机翼进行了气动伺服弹性剪裁,证明本方法能充分考虑结构与控制系统的作用,具有很好的收敛性.

This paper deals with flutter speed and gauge constrained minimum weight design of aeronautical composite wing structures with active controls. Subsonic doublet-lattice method is used to calculate the unsteady generalized aerodynamics.Flutter speed is calculated by state-space method. The optimal control theory is introduced to design the control law. Natural vibration modes are obtained by spectral transformation Lanczos method. The FEM is used to simulate the wing structure. Such finite elements as metallic and composite rod, shear panel, and normal stress quadrilateral and triangle elements are introduced. The web thickness,bar cross sectional area and the thickness of each composite layer are used as design variables. The objective function is the structural weight. The constraint function is the closed loop flutter speed and the technical requirements. The optimal problem is solved by feasible direction method. The derivatives of the constraint function with respect to design variables are calculated by finite difference method. An experimental wing is introduced to perform the optimal flutter suppression control law design, and the aeroservoelastic tailoring is applied to a composite wing structure, which gives very satisfactory results.