Efficiency analysis of vibration based crack diagnostics in rotating shafts

The comparative estimation of efficiency of different vibration diagnostics methods to detect damage of sub-critical size is complex and time-consuming process. So there was developed quite simple method of selection of most efficient vibration method of damage detection for a certain structure with a certain type of crack and at a certain type of deformation. This method is based on the determination of relative change of shaft's compliance caused by a crack with the use of linear fracture mechanics. As an example there was performed the comparative sensitivity analysis of several vibration methods of damage detection to the presence of longitudinal and transverse crack in a shaft at bending and torsional vibration.