Self-Diagnosis Method for Checking the Wayside Systems for Wheel-Rail Vertical Load Measurement

Abstract

Nowadays, wayside measurement systems of wheel-rail contact forces have acquired great relevance for the monitoring of rolling stock, especially for freight trains. Thanks to these solutions, infrastructure managers can check and monitor the status of rolling stock and, when necessary, impose corrective actions for the railway companies. On the other hand, the evaluation of contact forces is part of the rolling stock authorisation process [1] and a mainstone for the study of the running stability. The data provided by these measurements could give useful information to correlate the wear of the track with the frequency of applied loads, helping in the development of a better maintenance strategy of railway networks [2]. In this paper, the monitoring of vertical forces is based on the SMCV (Vertical Loads Monitoring System) method, where shear strains of the rail web are measured with a simple combination of four electrical strain gauges, placed on both sides of the rail web along each span. The research has identified self-diagnosis methods for the SMCV system to ensure the reliability and the quality of the measurements and to extend the knowledge of the system. The recorded signals have been processed and converted into easily interpretable physical quantities by means of MATLAB ® algorithm.

Estimation of sand electrification influence on locomotive wheel/ rail adhesion processes

“…This kind of integration was almost absent, especially in the railway field. Only differential modelling allows accurate analysis of the wheel/ rail contact problem (in terms of contact forces, position and shape of the contact patch, stresses and strains), while multibody modelling is generally accepted as the current standard for studying railway dynamics [6].…”

Response of Strain-Gauge-Based Tie Reaction Measurement Circuits under Dynamic Loading and Variable Support Conditions

“…These sensors do not require significant modification to track components during the installation process. Over the past few decades, research on strain-gauge-based systems for track response monitoring has been noticeable ( 1 – 33 ). Although the use of strain-gauge-based systems for train-induced wheel-load measurement is relatively common, only a few studies have recently reported the use of these systems for rail–tie interaction force measurement ( 2, 5, 7, 9, 13, 14, 26, 27, 29–33 ).…”

New Approach Measuring the Wheel/Rail Interaction Loads

“…Currently, the system for measuring the vertical force acting in wheel/rail interaction is consists of two complexes of strain gauges installed on the rail neck at an angle of 45°symmetrically relative to the middle of the sleeper gap, where signals from eight strain gauges are summed [9,29,31,34,35]. With this system, we can measure the difference in displacement between two sections at some distance within the same spacing, and the actual position of the vertical load has not been considered in the results.…”

“…Thus, a constant measured value for several tens of centimeters is obtained, providing more reliable measurements [31]. Subsequently, the method of "piecewise-continuous" registration of vertical forces was improved by many researchers, for example, in [34,36,37]. The effective zone of the "piecewise-continuous" registration scheme in one inter-sleeper gap is approximately 0.2 m.…”

“…Similarly, a simple transducer was developed that allows one to separate the effects of the vertical force from the lateral ones by placing it in the holes made in the rail neck near the centre of the rail lateral torsion [41]. The main disadvantages of the methods are the low sensitivity of deformation signals to lateral forces and violation of the track integrity [34,35].…”