直升机地面共振的非线性稳定性分析

 提出了计及起落架缓冲器和桨叶减摆器非线性阻尼时的直升机极限环的简化分析方法,讨论了由桨叶摆振运动的几何非线性和阻尼非线性引起的“混沌”（chaos）现象,以及初始扰动对不稳定响应的影响。试验结果与理论分析相一致。

NONLINEAR STABILITY ANALYSIS FOR HELICOPTER GROUND RESONANCE

A simplified analytical method for calculating the limit cycle behav ior of a helicopter model with nonlinear dampers in both the landing gear and blades is presented. It has provided a new way to protect effectively against the ground resonance instability for helicopter designers. The chaotic oscillations induced by both the geometrical nonlinearities of the blade lag motion and nonlinear dampers and the effect of initial disturbances on the instability response are also discussed; An experiment has been carried out using a helicopter scale model. The experimental results agree with those of the theoretical analysis.