Guided wave propagation in high-speed train axle and damage detection based on wave mode conversion

Abstract

Axle is the main bearing part of the bogie system on a high-speed train and is therefore requested on a higher reliability level. The high-speed train axle is thick-walled hollow cylindrical structure with variable cross section, which complicates ultrasonic guided wave propagation in the structure. Characteristics of the guided wave propagation in the train axle are systematically investigated in this study, so as to explore guided wave-based structural health monitoring (SHM) method for this kind of structure. Piezoelectric patches are used as actuator to excite waves in the axle. Generated wave signals using single actuator and circumferential, limited number of actuator configurations are compared to optimize the transducer network. The longitudinal wave modes are therefore selected for damage detection of this kind of structure. Based on the analytical and finite element analysis (FEA), when the symmetric longitudinal wave modes meet defect, if have, in the train axle with variable cross section, mode conversion will happen and asymmetric flexural wave modes are therefore generated. Wave mode conversion-based SHM technique is consequently proposed. The FEA results demonstrate the feasibility of guided wave-based SHM technique for high-speed train axle. Copyright © 2015 John Wiley & Sons, Ltd.