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Z. Li

221 records found

This paper presents a methodology for detecting and monitoring short pitch corrugation (SPC) under varying measurement conditions using vertical and longitudinal axle box acceleration (ABA) measurements. The main objective of the detection algorithm is to determine the likelihood ...
Friction behaviour at the wheel–rail interface is of critical importance for railway operations and maintenance and is generally characterised by creep curves. The V-Track test rig was used in this study to measure both the lateral and longitudinal creep curves with uncontaminate ...
Short pitch corrugation is a typical rail defect that lacks a thorough understanding and adequate root-cause solutions. This paper aims to identify the damage mechanism of short pitch corrugation through a microstructural analysis of a field rail sample. This sample made of R260M ...
As a critical factor in the degradation of rails and wheels, wheel-rail contact heat has been investigated with various analytical and numerical methods. However, the predicted temperature distributions and thermal loads have not been directly validated through measurements due t ...
Transition zones in railway tracks often degrade faster than other locations, yet traditional health assessments rely on infrequent track geometry measurements, limiting early detection of dynamic changes. This research presents an approach for more frequent evaluation of transit ...
This paper proposes an onboard measurement technology that combines a Laser Doppler Vibrometer (LDV) and an Axle Box Accelerometer (ABA) to approximate the dynamic load-response relationship of railway tracks. Unlike existing track-side and onboard technologies, this paper elimin ...
Frictional heat is generated at the wheel-rail interface during train operations, particularly under high slip ratios during acceleration and braking. Thermal effects can accelerate wear, induce plastic deformation, and contribute to thermal fatigue. Reliable modelling of wheel-r ...
This study experimentally and numerically investigated wheel–rail rolling contact fatigue (RCF), focusing on the initiation mechanisms of head check (HC). The experimental study was conducted using V-Track, a scaled test rig developed at TU Delft that is able to simulate real-lif ...

The development of short pitch rail corrugation

Extensive field monitoring and validation of numerical predictions

Short pitch corrugation is a major rail defect worldwide, and its development mechanism remains not fully understood. This work aims to better understand corrugation and validate some numerical predictions through extensive field monitoring. 105 corrugations on four sections of m ...
Nowadays, rolling stock can be equipped with high-frequency vibration sensors to continuously monitor rail infrastructures and detect defects. These moving sensors measure at high speeds and sampling frequencies, generating a massive amount of data that covers each track position ...
Inefficient management of rail surface defects can increase maintenance costs, safety hazards, service disruptions, and catastrophic failures like rail breaks. To achieve adequate management, having effective technology capable of timely detecting and frequently monitoring rail d ...
A train-borne laser Doppler vibrometer (LDV) directly measures the dynamic response of railway track components from a moving train, which has the potential to complement existing train-borne technologies for railway track monitoring. This paper proposes a holistic methodology to ...
Polygonal wear is a type of damage commonly observed on the railway wheel tread. It induces wheel-rail impacts and consequent train/track components failure. This study presents a finite element (FE) thermomechanical wheel-rail contact model, which is able to cope with the three ...
This paper aims at identifying the formation mechanism of short pitch rail corrugation using an improved configuration of a 1/5 scaled V-Track test rig. The loading conditions of the V-Track are designed to simulate the wheel-rail dynamic interactions on the tangent track. Corrug ...

Vibration transfer from underground train to multi-story building

Modelling and validation with in-situ test data

Excessive underground train-induced vibration becomes a serious environmental problem in cities. To investigate the vibration transfer from an underground train to a building nearby, an explicit-integration time-domain, three-dimensional finite element model is developed. The und ...
Creep curves characterise the behaviour of frictional forces at the wheel-rail interface. This study used the V-Track test rig to measure lateral and longitudinal creep curves under clean and dry contact conditions with practical wheel-rail contact pressures. The measured lateral ...
The Coefficient of Friction (CoF) is an important parameter affecting acceleration and braking behavior of trains, and consequently the inter-train distance and utilization of track. To optimize operation schedules, maximize railway capacity, and realize automatic train operation ...
Short pitch corrugation is a typical defect on rail surfaces that induces high level of noise and increases maintenance costs. Despite numerous research efforts, corrugation development mechanism has not yet been fully understood and root-cause solutions have not been developed. ...
This study presents a measuring framework for railway transition zones using a case study on the Swedish line between Boden and Murjek. The final goal is to better understand the vertical dynamics of transition zones using hammer tests, falling weight measurements, and axle box a ...
Wheel-rail high-frequency interaction is closely related to the formation of railway short-wave defects. Finite element (FE) method has been widely used to simulate wheel-rail dynamic systems, but its validity in modelling high-frequency interaction has not been fully demonstrate ...