204. high-speed non-contact passive-only ultrasonic inspection of rails from deconvolutions of wheel-generated noise
Name: Albert Yi-Ling Liang
Grad Year: 2021
Rail internal defects have been one of the major causes of train derailments in the U.S.. While the conventional ultrasound wheel probes has been widely implemented for rail track integrity inspection, it suffer from the drawback of limited testing speed (25 mph at most). This poster presents a new approach for ultrasonic rail inspection that utilizes non-contact receivers and no active transmitters. The transfer function between two points of the rail is reconstructed by deconvolutions of multiple pairs of receivers that sense the acoustics naturally excited in the rail by the running wheels. The deconvolution process eliminates the random effect of the excitation to reconstruct a stable acoustic transfer function of the rail. This radically new testing approach lends itself to extremely high testing speeds (as fast as the running train, e.g. 100 mph and above), that would enable the implementation of smart technology on trains running at normal operational speeds. A prototype based on this passive-only inspection idea has been constructed and tested with the T-18 testing vehicle of the Federal Railroad Administration at the Federal Transportation Technology Center (TTC) in Pueblo, CO in September 2016. Test runs were made at various speeds from 10 mph to 80 mph (the maximum speed allowed on the test track). The results show the feasibility of stable reconstruction of the transfer function from the random wheel excitation, as well as the detection of joints and welds present in the track. Additional tests are being planned to assess the effectiveness of the approach to detect internal defects relevant to rail safety.
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