开闭裂纹转子在非共振转速区的振动特性分析

摘要

Firstly,the motion equation of the Jeffcott rotor with a transverse open and closed crack is established.On this basis,The vibration characteristics of a cracked rotor in a non resonant region are studied by using the method of multi scale analysis of nonlinear vibration theory.The influence of crack parameters,the size and the direction on the vibration behavior of the cracked rotor is analyzed.The results show that all kinds of relationship is very complex.In non resonant speed area,the dynamic equilibrium position and the fundamental frequency of the cracked rotor are changed with the crack depth,The deeper the crack is,the greater the effect is.When unbalance is small,the effect of the unbalance and open and close crack is for the fundamental frequency component,but is nothing with high order harmonic.The influence of the phase angle of the unbalance and the normal crack direction on the frequency doubling amplitude is very significan.The results is generally the extremum in the vicinity of 0° or 180°.%首先建立了含横向开闭裂纹Jeffcott转子的运动方程,在此基础上,利用非线性振动理论的多尺度分析方法,研究了过程中非共振区的开闭裂纹转子振动特性.在模拟试验台上验证了裂纹参数、裂纹方向及不平衡量大小对含裂纹转子振动行为的关系,研究结果表明:在非共振转速区,裂纹转子的动平衡位置、基频均随裂纹深度而变化,裂纹越深影响越大;当不平衡量较小时,可以认为不平衡量与裂纹的相互作用仅对基频分量有影响,对高阶倍频影响很小;不平衡量与裂纹法向的相位角对各阶倍频振幅的影响非常显著,一般都是在0°或180°附近取得极值.