Damage detection for high-speed train axle based on the propagation characteristics of guided waves

The currently defect identification techniques based on guided wave is not feasible for high-speed train axle because the structure complicates wave propagation. A novel damage detection method especially for train axle is proposed in this paper. Piezoelectric patches are used as actuator to excite waves in the axle. Guided wave generated by single actuator and circumferential, limited number of actuator configurations is discussed to optimize the transducer network. The axle is simplified to a variable cross-sectional and thick-walled hollow cylindrical structure. Eight piezoelectric actuators that evenly distributed at the axle end surface are used to excite simplex longitudinal waves. Signals of circumferential and axial displacement of the monitoring points are researched before and after introducing the flaw on the surface, and their sensitivity to the depth and length of defect are also discussed. From the view of practical feasibility, the difference of signals from two axisymmetrical measure points of same axial position is proposed for the defect identification. Experimental verification is conducted, and the results demonstrate that the proposed approach is reliable in the axle inspection. Copyright (C) 2016 John Wiley & Sons, Ltd.