一种新的气动伺服弹性失稳模式的机理分析

某超声速导弹在飞行试验中发生了气动伺服弹性失稳导致的结构解体，通过对飞行试验数据的分析发现，气动伺服弹性失稳的振动频率高于弹体一阶弯曲模态频率，对导弹进行气动伺服弹性稳定性频域分析，并未发现该频率段发生气动伺服弹性失稳。针对该问题，建立了一种可以考虑数字式飞控系统采样过程影响的气动伺服弹性稳定性仿真分析方法，并对该导弹进行了建模分析，数值结果复现了该导弹的失稳现象。讨论了这一新型失稳现象发生的原因，包括连续结构滤波器离散化带来的移频现象和频率混叠问题。给出了对应的改进措施和相关的结论。 

Mechanism analysis of a new aeroservoelastic instability mode

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.