裂纹转子不平衡响应的有限元分析

THE ANALYSIS AND COMPUTATION OF THE UNBALANCE RESPONSE OF CRACKED ROTOR USING THE FINITE ELEMENT METHOD

首先由应力强度因子积分得到含裂纹轴段单元体的刚度矩阵，继而建立了含裂纹转子系统的运动微分方程。通过数值计算得到含裂纹转子系统的振动特性随裂纹的开闭、随裂纹的位置及深度间的变化关系。选定对裂纹比较敏感、又能反映结构动力特性的不平衡响应轨道（轴心轨迹）作为诊断裂纹的依据，编制了不平衡响应计算和动力分析程序。仿真试验结果表明，本文的裂纹诊断的有限元分析方法是可行的，具有较高的精度。

In this paper,the unbalance response of cracked rotors are investigated and analysed using the finiteelement method. Firstly, authors derive the stiffness matrix of cracked shaft element from an integration of thestress intensity factors(SIF),and establish the differential equations of motion of all typical elements(parts)accord-ing to their structural characteristics,Secondly, by assembling these equations together,the differential equation ofmotion of the cracked rotor system is obtained. Finally,a dynamic analysis software in which the effect of crack istaken into consideration has been compiled. The unbalance response orbits computed by the programme are checkedby experiments,and the agreement is quite good.