Abstract
This paper presents methods for continuous condition monitoring of railway switches and crossings (S&C, turnout) via sleeper-mounted accelerometers at the crossing transition. The methods are developed from concurrently measured sleeper accelerations and scanned crossing geometries from six in situ crossing panels. These measurements combined with a multi-body simulation (MBS) model with a structural track model and implemented scanned crossing geometries are used to derive the link between the crossing geometry condition and the resulting track excitation. From this analysis, a crossing condition indicator is proposed. The indicator is defined as the root mean square (RMS) of a track response signal γ that has been band-passed between frequencies corresponding to track deformation wavelength bounds of and for the vehicle passing speed (f = v/). In this way, the indicator ignores the quasi-static track response with wavelengths predominantly above and targets the dynamic track response caused by the kinematic wheel-crossing interaction governed by the crossing geometry. For the studied crossing panels, the indicator ( and ) was evaluated for γ = u, v, or a as in displacements, velocities, and accelerations, respectively. It is shown that this condition indicator has a strong correlation with vertical wheel–rail contact forces that is sustained for various track conditions. Further, model calibrations were performed to measured sleeper displacements for the six investigated crossing panels. The calibrated models show (1) a good agreement between measured and simulated sleeper displacements for the lower frequency quasi-static track response and (2) improved agreement for the dynamic track response at higher frequencies. The calibration also improved the agreement between measurements and simulation for the crossing condition indicator demonstrating the value of model calibration for condition monitoring purposes.
Highlights
In a railway network, the components that enable trains to switch from one track to another are called switches and crossings (S&C) or turnouts
The measurements were performed in the first week of June 2019 and are concurrent in time to provide a direct comparison between crossing geometry conditions and dynamic track response
Transition locations scanned geometrieswheels and a structural representation of theThe crossing panel were from implemented rail to crossing nose relative to thewhich tip of the crossing nose were compared
Summary
The components that enable trains to switch from one track to another are called switches and crossings (S&C) or turnouts. The examples of wheel–rail by track engineers To this end, this paper addresses the development of a model-based contacts concern a vehicle passing through crossing panel in the facing direction condition monitoring system the for the monitoring of crossing running surface geometry in andthe through (straight) routeballast as indicated theworth arrow at the bottom of the figure coming properties. Previous studies based on simulations have presented a clear correlation between crossing geometry, wheel–rail contact force, and track response [7,8]. Proposed a separation of the measured track response into quasi-static and dynamic domains based on deformation wavelength regions to monitor the ballast condition and crossing geometry, respectively. The agreement between measured and simulated track responses is evaluated By comparing these responses, the possibility of monitoring crossing geometry status via embedded sensors and condition indicators is addressed. The inspection images could come from cameras mounted onboard trains [18] or drones
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