Elastic wave analysis for broken rail detection

Abstract

A technique is presented to identify broken rail. The technique is based on elastic guided wave propagation through the rail. Broken rail detection is possible by either utilizing an impact device or energy propagating from the train wheel in contact with the rail. In principle, elastic guided wave energy propagates along the track, a natural wave-guide, until a broken rail is encountered. Pulse echo reflection is then used to identify broken rail. Considering an exponential decrease in penetration power from a source as a function of distance and natural energy filtering mechanisms of a rail, a simple model of guided wave propagation in rail is discussed. A feasibility demonstration of the concept is presented for a train going 50 miles per hour (90 km/hour) towards a broken rail with sensors fixed on rails close to the break.