基于Jeffcott转子的裂纹扩展动态特性分析

Dynamic Analysis of Crack Propagation Based on Jeffcott Rotor

针对于假设裂纹深度不变的裂纹转子模型,本文在现有Jeffcott转子模型基础上加入裂纹扩展变量,得到一个时变裂纹转子模型,对其进行动力学分析与断裂力学分析,采用数值计算方法得到其动态特性,并于固定裂纹深度相对比;数据结果表明,在亚临界转速下,裂纹转子响应中出现1X、2X、3X等频率分量,并出现分数次共振现象;在临界转速与超临界转速下裂纹转子响应基本只有1X分量构成;这些分析有助于裂纹转子的在线检测与寿命预测。

For the cracked rotor model on the assumption that the crack depth is constant.Based on the existing model,and filled with crack propagation variables.Then we get a time-varying model of cracked rotor.The analysis of dynamics and fracture mechanics analysis of the numerical calculation method was used to get the model’s dynamic characteristics,so we can compare it with the fixed crack depth.Data shows that in the sub critical speed 1X,2X,3X and other frequency components appear in the response of the cracked rotor,and the emergence of fractional resonance phenomenon.In the critical rotate speed and supercritical speed response of cracked rotor basically only 1X component.These analyses are helpful to the on-line detection and life prediction of cracked rotor.