拉杆转子预紧力建模及其诱发振动局部化研究  

Modelling of pre-tightening force in rod-fastened rotors and it induced vibration localization

作　　者：王奇 贾睿东 杨树华[2,3] 孟继纲[3] 张家忠[1] WANG Qi;JIA Ruidong;YANG Shuhua;MENG Jigang;ZHANG Jiazhong(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;School of Energy and Power Engineering,Dalian University of Technology,Dalian Liaoning 116024,China;Collaborative Innovation Center of Major Machine Manufacturing in Liaoning,Shenyang Blower Works Group Corporation,Shenyang 110869,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049 [2]大连理工大学能源与动力学院,辽宁大连116024 [3]沈阳鼓风机集团股份有限公司,辽宁重大装备制造协同创新中心,沈阳110869

出　　处：《航空动力学报》2023年第12期3020-3030,共11页Journal of Aerospace Power

基　　金：国家科技重大专项(779608000000200007);重点基础研究课题(2019-JCJQ-ZD-177-01)。

摘　　要：为探究拉杆转子在考虑接触面力学特性下预紧力失谐诱发振动的机理,从弹塑性理论及接触面微观角度,详细分析了单个微凸体在接触过程中的变形规律和力学特性,并通过高斯分布得到接触面宏观的力学接触模型。结合接触面力学特性,建立了一种保证其原始模型主要特征参数不变且能够确定其厚度的等效接触层;进一步通过这种等效接触层模型分析了拉杆预紧力降低和周向失谐时临界转速和固有频率的变化规律;利用波的传递揭示了预紧力周向失谐诱发拉杆转子振动模态局部化的机理。结果表明:预紧力减弱后,等效接触层刚度减小,临界转速和固有频率降低;随着预紧力失谐拉杆数量的增加,转子的临界转速和固有频率降低。当外部激励的频率处于拉杆转子的频率禁带时,振动能量无法传遍整体结构而积聚在局部区域,从而诱发了振动局部化现象。论文研究结果能够为复杂拉杆转子的动力学分析和优化设计提供参考方法。In order to explore the mechanism of the vibration induced by the pre-tightening mistune of the rod-fastened rotor considering the mechanical characteristics of the contact surface,and viewed from the elastoplastic theory and the microscopics of the contact surface,the deformation laws and mechanical characteristics of a single asperity in the contact process were analyzed in detail,and the macroscopic mechanical contact model of the contact surface was obtained through Gaussian distribution.First,an equivalent contact layer was established to ensure that the main characteristic parameters of the original model could be kept unchanged and its thickness was determined,based on the mechanical properties of the contact surface;then,the variation law of critical speed and natural frequency when the pre-tightening force was reduced and detuned in the circumferential direction was further analyzed by this equivalent contact layer model;finally,the mechanism of vibration mode localization of rod-fastened rotor induced by circumferential detuning of pre-tightening force was revealed by means of wave transmission.The results showed that the equivalent contact layer stiffness and the critical speed and natural frequency decreased as the pre-tightening reduced.Moreover,the critical speed and natural frequency of the rotor became lower,as the number of pre-tightening detuning rods increased.As the fluctuation frequency of the rod-fastened rotor was within the frequency stop-band,the vibration energy cannot be transmitted throughout the whole structure.The research results can provide a reference method for the dynamic analysis and optimal design of complex rod-fastened rotors.

关 键 词：拉杆转子 等效接触层 临界转速 预紧力失谐 振动模态局部化 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]