In order to solve the problem of the significant impact of the support system of an aeroengine on the vibration characteristics of the rotor subsystem,an analysis model of the support system was established to analyze its natural modes and dynamic characteristics.By comparing the calculated natural frequency with the experimental results,the accuracy of the model was verified.The model of rotor-support-casing-mounting joint system was established,and the critical speeds and strain energy of the whole system under high pressure rotor excitation were analyzed.The results show that there is a significant change in the stiffness value and phase of the sup-port system near the natural frequency,and the negative stiffness with continuous phase reversal occurs within a certain frequency band.Compared with the one-dimensional dual-rotor-support system with static stiffness,in terms of vibration mode,the whole engine model of the dual-rotor-support system with the same order of vibration mode can better reflect the different situations of casing vibration induced by the rotor;in terms of strain energy,due to the difficulty in describing the influence of negative stiffness using static stiffness,the use of dual-rotor-support system analysis method results in inaccurate calculation of the support strain energy for a certain order of vibration mode,and the method of analyzing engine vibration characteristics by using one-dimensional dual-rotor-support system with static stiff-ness will result in errors.The whole engine analysis model can better consider the coupling effect of the dynamic characteristics of the cas-ing on the rotor vibration,which is closer to actual engine operating conditions.The results can be used as a reference for the whole engine vibration design of aeroengines.
关键词
承力系统/动刚度/整机振动特性/航空发动机
Key words
support system/dynamic stiffness/whole engine vibration characteristics/aeroengine
维普
万方数据