Research On Acoustic Emission Monitoring For Cracks Of Shaft In Rotating Machinery

The fracture is a sort of critical failure form. If it occurs to a rotating shaft, which is the main component of rotating machinery, disastrous accidents, causing loss of life and destruction of wealth, may take place. Due to various environmental factors, inner and surface cracks will occur in the process of shaft service. Monitoring the propagation of cracks has great significance to the integrity appraisal and the fracture control of rotating shaft.Acoustic emission technology is a very good method of dynamic nondestructive testing. By way of acoustic emission monitoring material, finding the relationship between acoustic emission signals and cracks growth can analyze material deformation and fracture mechanisms. The traditional detection is performed after discovering flaw or carried out periodically. However, the new idea, forecasting and managing early defects and faults which may occur, can guarantee the greatest benefits on the premise of security.In this study, acoustic emission sensors, PCI-2 data acquisition card and AEwin software produced by PAC (Physical Acoustics Corporation) were adopted. They can both carry on real-time monitoring cracks of rotor, and look into the current situation and the historical condition at any time. The main research content includes the related theory of transducer; the acquisition and conversion of signal; the filtering and anti-noise of signal; signal transmission; data analysis. The characteristic parameters of acoustic emission monitoring for cracks of rotor were identified through experiments. The acoustic emission monitoring system is feasible and scalable.Monitoring shaft by way of acoustic emission technology is still at an experimental stage. Many of the methods and means are placed on trial step and not applied physically in fields. In this paper, the feasibility that acoustic emission technology is used to monitor cracks of shaft in rotating machinery was further verified. The development of fault diagnosis on shaft was further pushed forward.