Multifunctional flexible sensor array-based damage monitoring for switch rail using passive and active sensing

Abstract

A passive monitoring technique for switch rails will be very attractive because it does not require extra excitations and can realize large area monitoring. However, complex wheel-rail interactions and sparse sensors will affect the accuracy of local damage identification. In contrast, an active monitoring technique has high local damage quantification ability but has low efficiency for large area monitoring. This study firstly presents a combination of piezoceramic material Lead zirconate titanate (PZT) wafers with accelerometers to configure a multifunctional sensor array that brings together active and passive monitoring mechanisms. The multifunctional sensor arrays are produced in a flexible form, which are adapted to complex geometry and are easy to install. In complementary passive monitoring, each sub area's health state between 2 accelerometers is represented by reconstructing transfer functions, which are calculated from rail vibrations. The reconstructed transfer function in conjunction with principal component analysis (PCA)-based feature extraction is utilized for estimating the damaged sub area. Then accurate local damage identification can be realized through the active guided waves technique and correlation-based diagnostic imaging in conjunction with singular value decomposition (SVD). Simulation and experimental studies show the proposed mechanisms can identify the damaged sub area and basically extract damage locations with different lengths correctly with the sparse sensor array. Finally, based on a controlled experiment, the causes of the errors are evaluated and analyzed. The proposed mechanism can simplify data analysis, save monitoring time, and decrease the final cost.

Prediction of rail defect development using parametric bootstrapping modified Weibull equations

“…Validation is used to verify the results of the analysis 35 and to insure that these results are accurate. In order to perform this validation, approximately 110,000 defects were divided into two groupings; an analysis grouping and a validation grouping.…”

Insulated rail joint (IRJ) contact characterisation-an ultrasonic reflectometry approach for a cross-material interface

“…Applications of ultrasonic measuring techniques in railway systems have been widely seen covering active ultrasonic guided waves [24,25], passive acoustic emission [26][27][28], phased array [29], air-coupled ultrasonic testing [30], and emerging ultrasonic structural health monitoring (SHM) techniques [31][32][33]. On the other hand, some recent research works linking ultrasonic sensing with contact mechanics can be found in [34,35] by Song et al for bolt looseness monitoring based on fractal contact theory.…”

Evaluation of the Transverse Crack Depth of Rail Bottoms Based on the Ultrasonic Guided Waves of Piezoelectric Sensor Arrays

“…Deng et al, [19] proposed a segmented principal component analysis method to extract the features of the signals collected by the sensors at different positions and used SVM to quickly classify the cracks, corrosion, transverse cracks and other defects on the rail head surface. Hu et al, [20] realised crack location monitoring of 14 mm at the bottom of the rail through active and passive UGWs. The aforementioned findings indicate that UGW technology has positive outcomes for rail crack monitoring.…”