摘要
为了研究螺栓松脱对航空发动机转子动力学特性的影响,本文以航空发动机模拟转子为研究对象,建立了具有螺栓松动特性的有限元模型,利用螺栓松脱-横向裂纹等效法分析了螺栓连接结合面的开闭变化规律以及螺栓松脱单元的时变刚度特性,采用谐波平衡法求解了系统的运动方程,通过时域、频域和三维频谱图对比分析了有无螺栓松脱两种工况下系统的振动响应。研究表明,当存在螺栓松脱时,结合面的开闭区域与旋转角度有关,具体变化过程为完全闭合到完全张开再到完全闭合;当螺栓松脱数量较大时,主刚度随分界线位置的变化幅度较大,且会产生轴向-剪切、轴向-扭转、弯曲-扭转等耦合刚度;系统在一阶临界转速以及1/2,1/3,1/4临界转速附近出现峰值,在三维频谱图中除了基频成分还出现了二倍频成分2×、三倍频成分3×和四倍频4×成分。研究结果为航空发动机转子螺栓松脱的故障诊断提供了理论依据。
In order to study the influence of bolt loosening on the dynamic characteristics of aero-engine rotors, this paper takes the aero-engine simulated rotor as the research object, establishes a finite element model of bolt loosening characteristic. The loosening-transverse crack method is used to analyze the changes of the joint surface and the stiffness characteristics of bolt. The harmonic balance method is used to solve equation, and the system vibration response under two working conditions is analyzed through the comparison of time domain, frequency domain and three-dimensional spectrogram. Research shows that when there is a bolt loosening, the opening and closing area of the joint surface is related to the rotation angle. The specific change process is from closed to opened and then closed. When the number of loosening bolts is large, the main stiffness varies with the position of the dividing line is large, and it will produce axial-shear, axial-torsion,cure-torsion and other coupling stiffness. The system has peaks near the first-order critical speed and the 1/2, 1/3, and 1/4 critical speeds. In the spectrogram, in addition to the fundamental frequency component, there are also the double frequency component, the triple frequency component and the quadruple frequency component. The research results provide a theoretical basis for the fault diagnosis of aero-engine rotor bolt loosening.
作者
张庆山
裴世源
洪军
Qing-shan Zhang;Shi-yuan Pei;Jun Hong(Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System)
出处
《风机技术》
2021年第1期56-64,共9页
Chinese Journal of Turbomachinery
基金
国家自然科学基金资助项目(51975456)。
关键词
航空发动机
螺栓松脱
转子动力学
动力学特性
时变刚度特性
Aero-engine
Bolt Loosening
Rotor Dynamics
Dynamic Characteristics
Stiffness Characteristics
