基于导波多模态特征的法兰螺栓松动监测

Multiple guided wave modes transmitted through the flanged joint structure carry substantial information regarding connection status, which has great potential for achieving a high - precision non-in-situ monitoring technique. The looseness of a flange connection with eight bolts based on the multiple mode characteristics of guided waves was monitored. To capture multiple wave modes, a piezoelectric array design that can selectively excite and sense a single wave mode was proposed. The simulation and experiment verified the wave mode transducer’s selectivity. The wave mode transducer controlled four wave mode transmission through a flange to monitor bolt looseness in two stages: detecting looseness and identifying the loose position. The results showed that the wave mode characteristics not only effectively indicated bolt looseness but also provided detailed information on the loose position. After applying a support vector ma-chine,the accuracy of loose position identification reached 94.6%.