CAJ | 학술논문

本文采用适当的裂纹开闭模型，导出了固定坐标系中裂纹轴的刚度矩阵，建立了水平Jeffcott裂纹转子的振动微分方程，并对其进行了仿真计算。数值仿真表明：裂纹转子的响应中出现2x、3x等倍频分量，并产生分数次共振现象。在超临界转速区，倍频分量很小，但在响应的相频特性图中2x、3x处相位变化很大。参数β和主要影响1x谐波分量，对2x、3x等倍频分量影响很小。由于裂纹的存在，转子轨迹的中心也发生偏移。在临界转速附近，转子运行过程中裂纹处于常开或常闭状态。一般情况，当转子的偏心小于1时，裂纹在转子运行过程中总是时开时闭的。这些结论将有助于转子裂纹故障的监测和诊断。
본문채용괄당적렬문개폐모형，도출료고정좌표계중렬문축적강도구진，건립료수평Jeffcott렬문전자적진동미분방정，병대기진행료방진계산。수치방진표명：렬문전자적향응중출현2x、3x등배빈분량，병산생분수차공진현상。재초림계전속구，배빈분량흔소，단재향응적상빈특성도중2x、3x처상위변화흔대。삼수β화주요영향1x해파분량，대2x、3x등배빈분량영향흔소。유우렬문적존재，전자궤적적중심야발생편이。재림계전속부근，전자운행과정중렬문처우상개혹상폐상태。일반정황，당전자적편심소우1시，렬문재전자운행과정중총시시개시폐적。저사결론장유조우전자렬문고장적감측화진단。
The dynamic behavior of a horizontal cracked Jeffcott rotor is investigated in the paper.With the influence of whirl speed taken into account,the flexural stiffness matrix of the cracked shaft is derived.The equations of motion of the cracked rotor are derived and its dynamical behaviors are analyzed.Numerical analysis demonstrates that the responses of the vibration contain 2x,3x…exponents,reaching its maximum value when Ω=1/2,1/3…respectively.The components of high frequency almost disappear when the rotor runs in the supercritical region,but their phases change violently.β and influence mainly 1X component.The center of the motion orbit of the rotor changes because of the existence of crack.The crack keeps open or close when the rotor runs near the critical speed.Otherwise,it opens and closes by turns if is less than 1.