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针对航空发动机双转子系统受到一些无法预测的激励产生随机振动的现象,建立了不平衡双转子系统在随机激励作用下的运动方程。运用虚拟激励法,计算双转子系统在随机力下的位移响应功率谱密度,对其结构动力特性进行了研究。研究表明,当中介轴承刚度系数增大时,系统的固有频率增大并趋于定值。此时,外随机力引起的位移响应谱密度峰值减小并趋于无穷小值,而系统耦合作用引起的位移响应谱密度峰值先上升后减小,并在某个刚度值后,趋于无穷小值。根据研究结果提出了一些预防航空发动机双转子随机振动危害的措施。
Aiming at the phenomenon that aero-engine double-rotor system is subject to random vibration caused by some unpredictable excitation, the equations of motion of unbalanced dual-rotor system under random excitation are established. The virtual excitation method is used to calculate the displacement response power spectral density of the dual-rotor system under random force, and its dynamic characteristics are studied. The research shows that when the stiffness coefficient of the intermediate bearing increases, the natural frequency of the system increases and tends to be fixed. At this moment, the peak value of the displacement response spectral density caused by the external random force decreases and approaches the infinitesimal value, and the peak value of the displacement response spectral density caused by the coupling of the system first increases and then decreases, and after a certain stiffness value, it approaches infinitesimal value . Based on the research results, some measures to prevent the random vibration of aero-engine double rotors are put forward.