一种新的气动伺服弹性失稳模式的机理分析

Recently, the structure of a supersonic missile disintegrated due to aeroservoelastic instability in flight test. Through the analysis of flight test data, it is found that the vibration frequency of aerodynamic servo elastic instability is higher than the first-order bending elastic modal frequency of missile body. Based on the frequency domain analysis of aerodynamic servo elastic stability of missile, it is not found that aeroservoelastic instability occurs in this frequency band. To solve this problem, a simulation analysis method of aeroservoelastic stability considering the influence of sampling process of digital flight control system is established, and the missile is modeled and analyzed. The numerical results reproduce the instability phenomenon of the missile. The causes of this new instability phenomenon are discussed, including the frequency shift phenomenon caused by the discretization of continuous structure filter and frequency aliasing. Finally, the corresponding improvement measures and relevant conclusions are given.