机翼带外挂系统极限环颤振的区间分析

针对带有初偏间隙型非线性刚度的二元翼带外挂系统的极限环颤振,应用当量线化方法得出了颤振边界曲线,并根据颤振边界曲线用4阶Runge-Kutta法得到极限环相图,可明显看出极限环振动与普通周期振动的区别。然后引入了几个不确定量,通过区间分析方法给出了这些不确定量对机翼带外挂系统颤振边界曲线的影响,并用随机有限元法(FEM)验证区间分析方法的可靠性。进而可以得到一定来流速度下,具有不确定机翼外挂系统幅值的上下界,以及不确定参数对极限环相图的影响。知道机翼外挂幅值的上下界后,可以对外挂幅值进行适当控制。

Interval Analysis for Limit Cycle Flutter of a Wing with an External Store

In this article, the limit cycle flutter of a two-dimensional wing with an external store system with gaps in their connection is investigated. Applying the linearization method, the flutter boundary curve is gained, according to which the limit cycle phase pictures are acquired by using the 4th Runge-Kutta. Then the differences between the limit cycle flutter and normal cycle vibration are seen obviously. By using the interval analysis method the influence of the uncertainty in structure parameters on flutter boundary is studied. The stochastic finite element method (FEM) is introduced to verify the reliability of the interval analysis method. Moreover, for a fixed speed, the upper and lower amplitudes of the wing-store system with uncertainty are obtained and the influence of the uncertainty is cognized on the limit cycle phase pictures. Then proper control can be performed to restrain that known amplitude of the external store.