Smart rail pads for the continuous monitoring of sensored railway tracks: Sensors analysis

Abstract

The inclusion of sensors in railway track components will permit the automated and real-time monitoring of track behaviour and traffic conditions; necessary for adopting preventive maintenance strategies. In this sense, this paper assesses the applicability of three different sensor types, commonly used for engineering applications, to be included into rail pads to thus provide smart components with sensing properties to monitor railway tracks. Various types of accelerometer, piezoresistive and piezoelectric sensors were evaluated to determine their viability for smart rail pads. Results demonstrated that piezoelectric devices showed a linear correlation between signal output and stress levels on pads, in contrast to piezoresistive panels which presented a logarithmic response, and clearer signal pulses than the other sensors to detect changes in loading conditions or track response. Therefore, piezoelectrics presented the highest implementation potential for this application, considering its low cost and clearer ability to monitor variations in traffic and/or track state.