直升机尾桨/尾梁耦合动稳定性分析

根据激振实验数据,应用加速度响应频响函数方程组求解尾桨毂中心处的各阶模态频率,采用加速度导纳圆方法求得尾梁在尾桨毂中心处各阶模态的质量、阻尼和刚度。利用特征值方法分析了尾桨/尾梁耦合共振动稳定性。结果表明,尾梁纵向和垂向一阶模态是可能与尾桨摆振后退型模态产生耦合共振的危险模态,提高尾桨减摆器储能模量和尾梁一阶固有频率有利于提高系统稳定性。

Stability Analusis of Helicopter Tail Rotor/Boom Coupled Dynamic

In terms of shake test data, helicopter tail boom natural frequency was resolved by frequency-response functionsof acceleration. The model mass, damping and stiffness of tail boom were resolved by the method of admittance circle. Thedynamic stability of tail rotor/boom coupled resonance was analyzed by eigenvalue method. Results indicated that the firstboom vertical and longitudinal modes were the critical which might coupled with tail rotor regressive lead-lag mode.Height modulus of elastomeric lag damper and the boom first elastic mode natural frequency were benefit for avoiding sys.tem resonance and dynamic instability.