直升机桨叶混沌振动控制

在直升机旋翼桨叶动平衡试验中,桨叶挥舞模型可表述为带周期激扰的Duffing型振动方程.对控制桨叶挥舞的混沌振动问题,提出了用改变Duffing模型激扰项的方法来抑制系统的混沌振动状态.在Duffing模型中耦合3倍周期的振动激扰,用解析的Melnikov方法分别分析了Duffing模型在单倍周期激扰信号、3倍周期激扰信号或者在两种激扰信号共同作用下振动方程的混沌阈值区间,并根据不同的激扰信号对桨叶挥舞振动模型进行了仿真试验.结果证明在引入3倍周期的耦合激扰项后,系统混沌振动的区间范围大大减小了. 

Control of chaotic oscillation for helicopter rotor blade

The flapping model of rotor blade can be expressed as the model of Duffing′ oscillator with periodic exciting force in the dynamic balance test of helicopter rotor. To control the chaotic vibration in flapping, a method of changing exciting signals in Duffing′ model was proposed to restrain the chaos state in Duffing′ system. To couple a triple-period exciting signal in Duffing′ model, with the analytic method of Melnikov′ function based on chaos analysis, the chaos threshold of Duffing′ function were analyzed in the states of periodic exciting signal only, triple-period exciting signal only or combined action of the two signals respectively. Simulation experiments were also conducted according to the three kinds of exciting signals. The results indicate that the chaos range is reduced more evidently by coupling the triple-period exciting signal than that by period exciting signal only.