Non-Destructive Rail Monitoring for Defect Identification
Abstract
Non-destructive evaluation (NDE) of rail tracks is crucial to ensure the safety and reliability of rail transportation systems. In this work, we present a quantitative study using various signal processing methods to identify defects in rail structures. A diffuse field configuration was employed at few dozens of kiloHertz, where the emitter and receiver were remotely located, and wave energy propagated via multiple reflections within the medium. A reference database is first constructed by acquiring measurements at different rail positions and different torque levels (up to 50 N.m). The defect is then identified by comparing its signature to those stacked in the database. First, the destretching technique, based on Coda Wave Interferometry (CWI), is applied to correct for temperature-induced velocity variations. Then, the identification is performed using the Mean Square Error (MSE) metric and Orthogonal Matching Pursuit (OMP) technique. A comparative analysis of the both methods is conducted, focusing on their robustness and performance.