Root causes of numerous crack failures are attributed to the torsional oscillation between the turbine generator and the grid. To prevent such kind of failures, torsional vibration monitoring system has been intensively installed in reality and the torsional vibration is more and more observed in the operation. However, the mechanism of the characteristics of torsional vibration of the rotor system with and without cracks has not been well explored. Therefore this work presents the dynamic analysis and experimental study on the rotor system with transverse and slant cracks. For simulating the torsional oscillation in reality, excitation device is designed in the experiments and torsional vibration is measured. Based on this, the characteristics of lateral and torsional vibration of the rotor system are compared. The results show that, (i) although the slant crack presents more significant later-torsional vibration (especially for the breathing crack), the transverse cracked rotor system show higher amplitudes in the fundamental frequency and harmonic components (especially for the open crack) and (ii) the torsional excitation introduces more obvious vibration fluctuation in the rotor system with cracks (observed from the orbits and the torsional vibration).

大量裂纹故障的根本原因是涡轮发电机与电网之间的扭转振动。为了防止这种故障，实际上已经大量安装了扭转振动监测系统，并且在操作中越来越多地观察到扭转振动。然而，尚未充分研究具有和不具有裂纹的转子系统的扭转振动特性的机理。因此，这项工作提出了具有横向和倾斜裂纹的转子系统的动力学分析和实验研究。为了模拟现实中的扭转振动，在实验中设计了激励装置并测量了扭转振动。基于此，比较了转子系统的横向和扭转振动特性。结果表明，