Non-Contact Ultrasonic Guided Wave Inspection of Rails

Abstract

The University of California at San Diego (UCSD), unÄ‘er a FeÄ‘eral RailroaÄ‘ AÄ‘ministration (FRA) Office of Research anÄ‘ Development (R&D) grant, is Ä‘eveloping a system for high-speeÄ‘ anÄ‘ non-contact rail integrity evaluation. A prototype using an ultrasonic air-coupleÄ‘ guiÄ‘eÄ‘ wave signal generation anÄ‘ aircoupleÄ‘ signal Ä‘etection has been testeÄ‘ at the UCSD Rail Defect Farm. In aÄ‘Ä‘ition to a real-time statistical analysis algorithm, the prototype uses a specializeÄ‘ filtering approach Ä‘ue to the inherently poor signal-to-noise ratio of the air-coupleÄ‘ ultrasonic measurements in rail steel. The laboratory results inÄ‘icate that the prototype is able to Ä‘etect internal rail Ä‘efects with a high reliability. Extensions of the system are planneÄ‘ to aÄ‘Ä‘ rail surface characterization to the internal rail Ä‘efect Ä‘etection. In aÄ‘Ä‘ition to the Ä‘escription of the prototype anÄ‘ test results, numerical analyses of ultrasonic guiÄ‘eÄ‘ wave propagation in rails have been performeÄ‘ using a ÅISA algorithm anÄ‘ some of these results are shown. The numerical analysis has helpeÄ‘ Ä‘esigning various aspects of the prototype for maximizing its sensitivity to Ä‘efects.