Academic literature on the topic 'Insulated Rail Joints'
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Journal articles on the topic "Insulated Rail Joints"
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Gallou, M., B. Temple, C. Hardwick, M. Frost, and A. El-Hamalawi. "Potential for external reinforcement of insulated rail joints." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, no. 3 (December 22, 2016): 697–708. http://dx.doi.org/10.1177/0954409716684278.
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This paper aims to investigate the alternative ways of reducing the deterioration and failure of insulated rail joints of railway tracks. Joints deteriorate faster than rails due to the presence of structural discontinuity. This weakness results in extra displacement due to the applied load and dynamic force that results as a consequence. Overtime, this situation worsens as the impacts and applied stresses damage and soften the ballast and the supporting subgrade under the joint. This study initially presents a static finite element model designed to simulate the mechanics of insulated rail joints, and then a comparison is made between the plain rail and a suspended insulated rail joint under various support stiffnesses. The product design options of the reinforced insulated rail joints are then chosen as input variables of the model. The results of the model are compared with the field and laboratory data acquired via the Video Gauge, which is a new high-resolution optical measurement technique. The results show that the use of strap rails or more robust I-beam sections in the vicinity of the insulated rail joint to stiffen the support structure can significantly reduce the displacement and the subsequent dip angle seen in an insulated rail joint. This potentially presents a means of improving the behaviour of the insulated rail joints. Their impact becomes more significant for soft support conditions. Although these results are indicative of new conditions for insulated rail joints, the field measurements indicate that the magnitude of deflection of insulated rail joints is a result of the structural discontinuity of the rails, the dynamic P2 force, the wheel condition, the degraded ballast and it significantly increases with time under repeated load. Thus, it is recommended that a careful field implementation and testing will indicate the effect of an external enhancement on the timely degradation of insulated rail joints.
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Mandal, Nirmal Kumar. "Ratchetting damage of railhead material of gapped rail joints with reference to free rail end effects." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 231, no. 2 (August 4, 2016): 211–25. http://dx.doi.org/10.1177/0954409715625361.
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Free ends of insulated rail joints occur because gaps between the rails and endposts can be created due to pull-apart problems as the rails contract longitudinally in winter and by degradation of railhead material. Dynamic behaviour of gapped rail joints changes adversely compared to that of insulated rail joints. Thus, material degradation and damage of gapped rail joint components such as rail ends, joint bars, etc. are accelerated. Only limited literatures are available addressing the free end of rail effects at rail joints, targeting stress and pressure distributions in the vicinity of the rail joints. To understand clearly the material degradation and delamination process of gapped rail joints, a thorough analysis of failure of both insulated rail joints and gapped rail joints and subsequent damage of the railhead material is necessary to improve the service life of these joints. A new three-dimensional finite element analysis is carried out in this paper to assess damage to railhead material when gapped rail joints form. Both narrow (5 mm) and wide (10 mm) gaps are considered, using a peak vertical pressure load of 2500 MPa applied cyclically at one rail end, forming vertical impacts. Stress distributions and plastic deformations in the vicinity of gapped rail joints are quantified using finite element analysis data and compared with that of the insulated rail joints to show the effects of free rail ends. Residual stress and strain distributions indicate the damage to the railhead material. Equivalent plastic strain (PEEQ) quantifies the progressive damage to the railhead material at the rail ends. The free end of rail effects can be further illustrated by comparing PEEQ for insulated rail joints and gapped rail joints. The railhead material of 5 and 10 mm gapped rail joints is more sensitive to permanent deformation compared to that of the corresponding insulated rail joints. Therefore, free rail end joints pose an increased potential threat to rail operations in relation to crack initiation, damage and premature failure of railhead material.
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Gallou, M., M. Frost, A. El-Hamalawi, and C. Hardwick. "Assessing the deflection behaviour of mechanical and insulated rail joints using finite element analysis." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, no. 9 (April 8, 2018): 2290–308. http://dx.doi.org/10.1177/0954409718766925.
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Rail joints constitute a weak component in the railway system. In this paper, three-dimensional finite element analyses are carried out to study the structural deflection performance of rail joints under a fatigue static test through vertical stiffness assessment. Four different types of four-bolted joints are investigated under a dynamically enhanced static load including a glued insulated rail joint, a dry encapsulated insulated rail joint, a dry non-glued insulated rail joint and a mechanical rail joint. The analysis focused on the accurate simulation of the contact types between the interfaces of rail joint components, namely the rail, fishplate faces, bolts and insulating materials. It also focused on the effect of the elastic supporting structure of the joint with regard to the overall joint deflection. The effect of bolt pre-tension is included in the model. The vertical displacement of insulated rail joints is measured experimentally by dial gauges and a video technique in both laboratory and field settings. The numerical modelling investigated the effect of different contact types on the interfaces of the rail joint components during the performance of fishplates, and of the rail in the vicinity of the rail joint under a given support condition. The vertical displacement of the rail joint was presented and assessed against specified limits of endurance tests and field-measured deflection values that validate the model. Stress distribution in the fishplates was presented that could allow the calculation, through a stress-life approach, the fatigue life of the fishplates and, consequently, of the joints due to repeated wheel passage. A comparison of the performance of the aforementioned rail joint types is included. The results indicate that this finite element model can be routinely used in industries, as it was used in the UK Rail industry study, to allow designers to optimize the life expectancy of insulated rail joints.
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Németh, Attila, Zoltán Major, and Szabolcs Fischer. "FEM Modelling Possibilities of Glued Insulated Rail Joints for CWR Tracks." Acta Technica Jaurinensis 13, no. 1 (February 18, 2020): 42–84. http://dx.doi.org/10.14513/actatechjaur.v13.n1.535.
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In this paper the authors detail the possibilities of modelling of finite element method (FEM) of glued insulated rail joints which are applied in railway tracks with continuously welded rails (CWR). A lot of laboratory tests (static and dynamic 3-point bending tests, axial pulling tests) were executed on glued insulated rail joints, the specimens were related to three different rail profiles applied in Hungary: MÁV 48.5; 54E1 (UIC54), 60E1 (UIC60), respectively. The static bending tests with many bay length values were conducted, before and after dynamic (fatigue) tests. 2-D beam models were made in FEM software using semi-rigid hinge as the simplified connection of fishplated glued insulated rail joint. The FEM models were calibrated and then validated with the static vertical displacement values in the middle-bay position measured in laboratory. The model validation was conducted with two methods.
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Németh, Attila, and Szabolcs Fischer. "INVESTIGATION OF THE GLUED INSULATED RAIL JOINTS APPLIED TO CWR TRACKS." Facta Universitatis, Series: Mechanical Engineering 19, no. 4 (December 12, 2021): 681. http://dx.doi.org/10.22190/fume210331040n.
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This article summarizes the research results related to our own conducted extensive laboratory tests of polymer composite and steel fishplated glued insulated rail joints (GIRJs), namely axial tensile tests as well as vertical static and dynamic tests. The investigation dealt with the examination of GIRJs assembled with steel and special glass-fiber reinforced plastic (polymer composite) fishplates, both of them for CWR railway tracks (i.e. so-called gapless tracks or, in other words, railway tracks with continuously welded rails). The exact rail joint types were MTH-P and MTH-AP, consistently. The MTH P types have been commonly applied for many years in the CWR tracks in Europe, mainly in Hungary. The MTH-AP rail joints consist of fishplates that are produced by the APATECH factory (Russia). They are made of a fiberglass-amplified polymer composite material at high pressure and controlled temperature. This solution can eliminate electrical fishplate lock and early fatigue failures just as it can ensure adequate electrical insulation. The advantage of such rail joints can be that they are probably able to ensure the substitution of the glued insulated rail joints with relatively expensive steel fishplates currently applied by railway companies, e.g. Hungarian State Railways (MÁV). The aim of the mentioned research summarized in this paper is to formulate recommendations on technical applicability and on the technological instructions that are useful in everyday railway operation practice on the basis of the measurements and tests carried out on rail joints in laboratory.
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Chen, Y. C., and J. H. Kuang. "Contact stress variations near the insulated rail joints." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 216, no. 4 (July 1, 2002): 265–73. http://dx.doi.org/10.1243/095440902321029217.
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The effect of an insulated rail joint (IRJ) on the contact stress variation near wheel-rail contact zones was simulated by employing three-dimensional finite element models. Three linear elastic IRJ materials, i.e. epoxy-fibreglass, polytetrafluoroethylene (PTFE) and Nylon-66, were investigated. Contact elements were used to simulate the interaction between the wheel and rail contact points. Numerical results showed that the presence of IRJ might significantly affect the wheel-rail contact stress distributions. Results also indicated that the traditional Hertzian contact theory is no longer available to predict the contact stress distribution around the rail joints.
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Huang, S. W., S. Burgess, L. Németh Wehrmann, D. Nolan, and Tara Chandra. "Insulated Rail Joints for Signalling Applications." Materials Science Forum 539-543 (March 2007): 4069–74. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4069.
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Insulated rail joint assemblies provide electrical insulation between two sections of rail for signalling purposes. In this work, rail steel was successfully bonded to PSZ ceramic using an active brazing technique. In order to increase the wettability of the PSZ ceramics, titanium coating was deposited on the ceramic surface using a filtered arc deposition system. A filler metal called BVAg-18 (60%Ag-30%Cu-10%Sn) was used and the joining was performed at a temperature of 750 °C. Bonding between partially stabilised zirconia and rail steel with BVAg-18 filler metal was not achieved using a standard brazing method. Bonding did occur with the BVAg-18 filler metal using the advanced brazing technique of active metal brazing, with best results obtained using a brazing temperature of 750oC and a dwell time of 10 minutes. The microstructure of the coating and joint interface were characterised by XRD, SEM and EDS.
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Luzin, Vladimir, C. Rathod, D. Wexler, Paul Boyd, and Manicka Dhanasekar. "Residual Stresses in Rail-Ends from the in-Service Insulated Rail Joints Using Neutron Diffraction." Materials Science Forum 768-769 (September 2013): 741–46. http://dx.doi.org/10.4028/www.scientific.net/msf.768-769.741.
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Insulated rail joints (IRJs) are an integral part of the rail track signaling system and pose significant maintenance and replacement costs due to their low and fluctuating service lives. Failure occurs mainly in rail head region, bolt- holes of fishplates and web-holes of the rails. Propagation of cracks is influenced by the evolution of internal residual stresses in rails during rail manufacturing (hot-rolling, roller-straightening, and head-hardening process), and during service, particularly in heavy rail haul freight systems where loads are high. In this investigation, rail head accumulated residual stresses were analysed using neutron diffraction at the Australian Nuclear Science and Technology Organisation (ANSTO). Two ex-service two head-hardened rail joints damaged under different loading were examined and results were compared with those obtained from an unused rail joint reference sample in order to differentiate the stresses developed during rail manufacturing and stresses accumulated during rail service. Neutron diffraction analyses were carried out on the samples in longitudinal, transverse and vertical directions, and on 5mm thick sliceed samples cut by Electric Discharge Machining (EDM). For the rail joints from the service line, irrespective of loading conditions and in-service times, results revealed similar depth profiles of stress distribution. Evolution of residual stress fields in rails due to service was also accompanied by evidence of larger material flow based on reflected light and scanning electron microscopy studies. Stress evolution in the vicinity of rail ends was characterised by a compressive layer, approximately 5 mm deep, and a tension zone located approximately 5- 15mm below the surfaces. A significant variation of d0 with depth near the top surface was detected and was attributed to decarburization in the top layer induced by cold work. Stress distributions observed in longitudinal slices of the two different deformed rail samples were found to be similar. For the undeformed rail, the stress distributions obtained could be attributed to variations associated with thermo-mechanical history of the rail.
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Rathod, C., D. Wexler, T. Chandra, and H. Li. "Microstructural Characterisation of Railhead Damage in Insulated Rail Joints." Materials Science Forum 706-709 (January 2012): 2937–42. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.2937.
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As an integral part the railway network infrastructure, insulated rail joints (IRJs) electrically isolate track segments providing critical feedback to both track signaling and train position detection systems. Because of the discontinuous nature of IRJs, accumulated damage at the railhead is high. Failure modes include plastic flow of metal across joints, bolt and fishplate failures, delamination of insulated material and, as a result of rolling contact fatigue, end post and endpost surface damage. In the current investigation, microstructural changes in the vicinity of endposts of IRJs made from both surface coated and uncoated rail are investigated using techniques of optical and scanning electron microscopy. Damaged IRJs made from pearlitic head hardened rail steel are compared with head hardened rail steel laser coated with martensitic stainless steel, the latter having an increased service life. Problems associated with the surface coating are identified and approaches to further improving IRJ resistance to rolling contact fatigue suggested. Keywords: Insulated rail joints, rail, head hardened, surface coated rail
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N. Zong, D. Wexler, and M. Dhanasekar. "Structural and Material Characterisation of Insulated Rail Joints." Electronic Journal of Structural Engineering 13, no. 1 (January 1, 2013): 75–87. http://dx.doi.org/10.56748/ejse.131631.
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Insulated rail joints are designed in a similar way to butt jointed steel structural systems, the difference being a purpose made gap between the main rail members to maintain electrical insulation for the proper functioning of the track circuitry at all times of train operation. When loaded wheels pass the gap, they induce an impact loading with the corresponding strains in the railhead edges exceeding the plastic limit significantly, which lead to metal flow across the gap thereby increasing the risk of short circuiting and impeding the proper functioning of the signalling and broken rail identification circuitries, of which the joints are a critical part. The performance of insulated rail joints under the passage of the wheel loading is complex due to the presence of a number of interacting components and hence is not well understood. This paper presents a dynamic wheel-rail contact-impact modelling method for the determination of the impact loading; a brief description of a field experiment to capture strain signatures for validating the predicted impact loading is also presented. The process and the results of the characterisation of the materials from virgin, in-service and damaged insulated rail joints using neutron diffraction method are also discussed.
Dissertations / Theses on the topic "Insulated Rail Joints"
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Pang, Tao, and tony_pang@hotmail com. "Studies on Wheel/Rail Contact Impact Forces at Insulated Rail Joints." Central Queensland University. Centre for Railway Engineering, 2008. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20080410.154708.
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To investigate the wheel/rail contact impact forces at insulated rail joints (IRJs), a three-dimensional finite element model and strain gauged experiments are employed and reported in this thesis. The 3D wheel/rail contact-impact FE model adopts a two-stage analysis strategy in which the wheel-IRJ railhead contact is first established in the static analysis and the results transferred to dynamic analysis for impact simulations. The explicit FE method was employed in the dynamic analysis. The Lagrange Multiplier method and the Penalty method for contact constraint enforcement were adopted for the static and dynamic analyses respectively.
The wheel/rail contact-impact in the vicinity of the end post is exhibited via numerical examples from the FE modelling. The wheel/rail contact impact mechanism is investigated. The strain gauged experiments which consist of a lab test and a field test are reported. The signature of the strain time series from the field test demonstrates a plausible record of the dynamic responses due to the wheel/rail contact impact. By using the experimental data, both the static and the dynamic FE models are validated.
It is found that the stiffness discontinuity of the IRJ structure causes a running surface geometry discontinuity during the wheel passages which then causes the impact in the vicinity of the end post. Through a series of sensitivity studies of several IRJ design parameters, it is shown that the IRJ performance can be effectively improved with optimised design parameters.
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Zong, Nannan. "Development of optimal designs of insulated rail joints." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/61125/1/Nannan_Zong_Thesis.pdf.
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Proper functioning of Insulated Rail Joints (IRJs) is essential for the safe operation of the railway signalling systems and broken rail identification circuitries. The Conventional IRJ (CIRJ) resembles structural butt joints consisting of two pieces of rails connected together through two joint bars on either side of their web and the assembly is held together through pre-tensioned bolts. As the IRJs should maintain electrical insulation between the two rails, a gap between the rail ends must be retained at all times and all metal contacting surfaces should be electrically isolated from each other using non-conductive material. At the gap, the rail ends lose longitudinal continuity and hence the vertical sections of the rail ends are often severely damaged, especially at the railhead, due to the passage of wheels compared to other continuously welded rail sections.
Fundamentally, the reason for the severe damage can be related to the singularities of the wheel-rail contact pressure and the railhead stress. No new generation designs that have emerged in the market to date have focussed on this fundamental; they only have provided attention to either the higher strength materials or the thickness of the sections of various components of the IRJs. In this thesis a novel method of shape optimisation of the railhead is developed to eliminate the pressure and stress singularities through changes to the original sharp corner shaped railhead into an arc profile in the longitudinal direction. The optimal shape of the longitudinal railhead profile has been determined using three nongradient methods in search of accuracy and efficiency: (1) Grid Search Method; (2) Genetic Algorithm Method and (3) Hybrid Genetic Algorithm Method. All these methods have been coupled with a parametric finite element formulation for the evaluation of the objective function for each iteration or generation depending on the search algorithm employed.
The optimal shape derived from these optimisation methods is termed as Stress Minimised Railhead (SMRH) in this thesis. This optimal SMRH design has exhibited significantly reduced stress concentration that remains well below the yield strength of the head hardened rail steels and has shifted the stress concentration location away from the critical zone of the railhead end. The reduction in the magnitude and the relocation of the stress concentration in the SMRH design has been validated through a full scale wheel – railhead interaction test rig; Railhead strains under the loaded wheels have been recorded using a non-contact digital image correlation method. Experimental study has confirmed the accuracy of the numerical predications.
Although the SMRH shaped IRJs eliminate stress singularities, they can still fail due to joint bar or bolt hole cracking; therefore, another conceptual design, termed as Embedded IRJ (EIRJ) in this thesis, with no joint bars and pre-tensioned bolts has been developed using a multi-objective optimisation formulation based on the coupled genetic algorithm – parametric finite element method. To achieve the required structural stiffness for the safe passage of the loaded wheels, the rails were embedded into the concrete of the post tensioned sleepers; the optimal solutions for the design of the EIRJ is shown to simplify the design through the elimination of the complex interactions and failure modes of the various structural components of the CIRJ.
The practical applicability of the optimal shapes SMRH and EIRJ is demonstrated through two illustrative examples, termed as improved designs (IMD1 & IMD2) in this thesis; IMD1 is a combination of the CIRJ and the SMRH designs, whilst IMD2 is a combination of the EIRJ and SMRH designs. These two improved designs have been simulated for two key operating (speed and wagon load) and design (wheel diameter) parameters that affect the wheel-rail contact; the effect of these parameters has been found to be negligible to the performance of the two improved designs and the improved designs are in turn found far superior to the current designs of the CIRJs in terms of stress singularities and deformation under the passage of the loaded wheels. Therefore, these improved designs are expected to provide longer service life in relation to the CIRJs.
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Mayers, Adam Cristopher. "An investigation of the structural mechanics of insulated rail joints." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/122878/1/Adam_Mayers_Thesis.pdf.
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Insulated rail joints, are a safety critical part of track signalling systems, which are used extensively in rail networks worldwide. However, these joints are failure prone, and susceptible to cracking and fracture, which has resulted in a number of notable accidents in the past, and major cost to industry. This thesis investigates the structural behaviour of these joints, via analytical modelling and field testing in the Pilbara region of Western Australia. The ultimate goals of this work are to reduce maintenance and outage costs, and, more importantly, improve safety for operators and passengers.
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Charlton, Zachary. "Innovative Design Concepts for Insulated Joints." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/35509.
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The main goal of this research is to develop new and innovative designs for insulated rail joints for improved life cycle and higher cost effectiveness. The research focuses on using electrically insulating materials that replace the epoxy used in current bonded insulated joints. Insulated joints (commonly known as â IJsâ ) are widely used on railways to electrically insulate rail segments from each other, while mechanically connecting them together. The electrical insulation is necessary for accommodating track signals. The mechanical strength is needed to ensure the rail and IJs are able to withstand the vertical, longitudinal, and lateral forces that commonly occur on track.
Insulating materials that can replace the epoxy used in bonded insulated joints are researched. The electrical insulation properties and mechanical strength of different materials are examined to determine the suitability of different materials for use in insulated joint. The most promising materials for use are determined to be fiber reinforced polymers and ceramics. Insulated joint designs are developed to accentuate the strengths of these two materials. The Insulating Metal Composite (IMC) insulated joint design that uses ceramics is determined to be the most promising of the new designs and is pursued through prototype fabrication.
This particular joint design is analyzed structurally using both closed form analysis and FEA analysis using the software package ABAQUS. Electrical analysis using PSPICE is carried out on the joint. Prototypes of several design iterations of the insulating metal composites are built and tested. A proof of concept static bending test of the insulating metal composites used to build the IMC insulated joint is performed using a Tinius Olsen compressive tester. A rolling-wheel load test is performed on a prototype IMC component installed in rail. Finally, a prototype of a complete IMC insulated joint is fabricated and installed on the FAST test track at TTCI facility in Pueblo, Colorado for field evaluation. Electrical testing using a megohmmeter is performed on a complete prototype joint.
Structural analysis shows that the components used to construct the IMC insulated joint can withstand the vertical and longitudinal loads applied to them. Electrical analysis shows that the joint can provide adequate electrical insulation and provides the required dielectric strength in the AREMA Manual for Railway Engineering. The proof of concept test shows that an IMC component can withstand 100 kips of static load without damage. The rolling-wheel load test shows that the ceramic in the IMC components can withstand a large shock load and that the rail used in the IMC insulated joints can survive repeated and shock loads. The testing of the prototype joint on the FAST track, which is ongoing at this time has shown that the new joint concept is fully capable of providing adequate electrical insulation and mechanical strength throughout the expected life of IJs.Master of Science
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Elshukri, Fathi A. "An experimental investigation and improvement of insulated rail joints (IRJs) end post performance." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12066/.
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Insulated rail joints are a safety valve in railways that are used as part of the signalling system to determine the position of a train. Insulated rail joints are the weakest part of the railroad, where their life ranges between a third and half of the life of rails. One of the most significant issues in insulated rail joints is metal flow, and damage and loss of the end post. Major causes of these issues include sliding wear, impact wear, wear due to rolling/sliding contact, and wear due to rail compression and plastic flow of rail material. In this study experimental investigations have been applied to improve insulated rail joints. The aim of this work was to experimentally determine the resistance to sliding wear, impact wear, rolling/sliding contact wear, compression wear of five specimens of end post materials with different properties against train wheel material (steel), and the influence of tests parameters and lubrication on these materials. The end post materials were classified into thermoplastic materials such as Nylon 12, Nylon 66 and Nylon66a materials and thermosetting materials such as Epoxy Glass and Phenolic Resin Bonded Fabric materials according to melting point temperature.
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Bandula-Heva, Thaminda Madunoraj. "Ratchetting of railhead in the vicinity of the gap of the insulated rail joints." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/64442/1/Thaminda_Bandula_Heva_Thesis.pdf.
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Insulated Rail Joints (IRJs) are designed to electrically isolate two rails in rail tracks to control the signalling system for safer train operations. Unfortunately the gapped section of the IRJs is structurally weak and often fails prematurely especially in heavy haul tracks, which adversely affects service reliability and efficiency. The IRJs suffer from a number of failure modes; the railhead ratchetting at the gap is, however, regarded as the root cause and attended to in this thesis. Ratchetting increases with the increase in wheel loads; in the absence of a life prediction model, effective management of the IRJs for increased wagon wheel loads has become very challenging. Therefore, the main aim of this thesis is to determine method to predict IRJs' service life.
The distinct discontinuity of the railhead at the gap makes the Hertzian theory and the rolling contact shakedown map, commonly used in the continuously welded rails, not applicable to examine the metal ratchetting of the IRJs. Finite Element (FE) technique is, therefore, used to explore the railhead metal ratchetting characteristics in this thesis, the boundary conditions of which has been determined from a full scale study of the IRJ specimens under rolling contact of the loaded wheels.
A special purpose test set up containing full-scale wagon wheel was used to apply rolling wheel loads on the railhead edges of the test specimens. The state of the rail end face strains was determined using a non-contact digital imaging technique and used for calibrating the FE model. The basic material parameters for this FE model were obtained through independent uniaxial, monotonic tensile tests on specimens cut from the head hardened virgin rails. The monotonic tensile test data have been used to establish a cyclic load simulation model of the railhead steel specimen; the simulated cyclic load test has provided the necessary data for the three decomposed kinematic hardening plastic strain accumulation model of Chaboche.
A performance based service life prediction algorithm for the IRJs was established using the plastic strain accumulation obtained from the Chaboche model. The predicted service lives of IRJs using this algorithm have agreed well with the published data.
The finite element model has been used to carry out a sensitivity study on the effects of wheel diameter to the railhead metal plasticity. This study revealed that the depth of the plastic zone at the railhead edges is independent of the wheel diameter; however, large wheel diameter is shown to increase the IRJs' service life.
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Gallou, Maria. "The assessment of track deflection and rail joint performance." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/36196.
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Track stiffness is the one of the most critical parameters of the track structure. Its evaluation is important to assess track quality, component performance, localised faults and optimise maintenance periods and activities. Keeping the track stiffness within acceptable range of values is connected with keeping the railway network in a satisfactorily performing condition, allowing thereby upgrade of its capacity (speed, load, intensity). Current railway standards are changing to define loading and stiffness requirements for improved ballasted and ballastless performance under high speed train traffic. In recent years various techniques have been used to measure track deflection which have been also used to validate numerical models to assess various problems within the railway network. Based on recent introduction of the Video Gauge for its application in the civil engineering industry this project provides the proof of effective applicability of this DIC (Digital image correlation) tool for the accurate assessment of track deflection and the calculation of track stiffness through its effective applicability in various track conditions for assessing the stiffness of various track forms including track irregularities where abrupt change in track stiffness occur such as transition zones and rail joints. Attention is given in validation of numerical modelling of the response of insulated rail joints under the passage of wheel load within the goal to improve track performance adjacent to rail joints and contribute to the sponsoring company s product offering. This project shows a means of improving the rail joint behaviour by using external structural reinforcement, and this is presented through numerical modelling validated by laboratory and field measurements. The structural response of insulated rail joints (IRJs) under the wheel vertical load passage is presented to enhance industry understanding of the effect of critical factors of IRJ response for various IRJ types that was served as a parametric FE model template for commercial studies for product optimisation.
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Beaty, P. "Experimental testing procedures to investigate and improve insulated rail joint design and life cycle." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/10159/.
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An insulated block joint (IBJ) is a mechanical joint which joins two abutting railway rails whilst keeping them electrically separate from each other. They are an integral component of block signalling systems as they allow for train detection within the network, however, they are a weak point in the system where failures can occur. The aims of this research work were to develop test regimes to enable life cycle analysis of IBJs and use these tests to assess the performance of different materials and designs. This has been achieved by the use of specimen, component and full assembly level testing. Specimen and component level shear testing has been carried out which has allowed for the assessment of different glues and insulating materials that are used in an IBJ and also has tested differing design principles. These experiments have been monitored using ultrasound techniques to investigate how failures within the insulating materials occur. It has been found that by using a full fit design with a glass fibre lining material an improvement in the shear strength of the IBJ can be obtained in comparison to a standard UK design. A full scale testing regime was developed in order to cyclically load assembled IBJs and compare a new joint design with the standard design. The new test method enabled testing of the IBJs to failure and gave a good comparison between two joints. Ultrasonic monitoring techniques have been implemented based on knowledge gained in component level testing which has allowed for the assessment of de-bonding within the IBJs as the test is carried out. Further specimen and full scale testing was carried out and a novel test regime was used to experimentally model lipping, the plastic flow of steel over the end of an IBJ causing electrical failure. This test regime allowed for the testing of different materials in both the endpost and the rail. By using a hardened rail steel or a hardened laser clad layer on the running surface of the rail it has been found that lipping performance can be improved greatly. The work has led to the development of a new design of IBJ that incorporates material and design changes and aims to increase the life cycle of the IBJ by increasing static and dynamic stiffness and improving the rail material with respect to lipping performance. Further work on in service testing of laser cladding technology could be performed to further the work that has been achieved using twin disc testing.
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De, Koker Jan Johannes. "Insulated rail joints." Thesis, 2014. http://hdl.handle.net/10210/11515.
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Chia-LingHsieh and 謝佳陵. "Numerical Stress Analysis of Bonded Insulated Rail Joints." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/vj349f.
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碩士國立成功大學
土木工程學系
104
In the study, the finite element package of ABAQUS is utilized to numerically analyze the stress distributions of bonded insulated rail joints with different geometries and material properties. At first, a numerical model composed of rails, joint bars, epoxy, bolts, insulated sleeves for bolts, insulated sheet between rails, and sleepers, was generated by using the finite element software. Next, a vertical concentrated load was imposed on the bonded insulated rail joint to simulate the weight of a train passing on it. The effects of the suspended and supported placement of sleepers, the thickness and Poisson’s ratio of epoxy, and the length of joint bar on the stress distributions at the interfaces between steel rail and epoxy were evaluated numerically. Numerical results show that the interfacial stresses at the boundaries between steel rail and epoxy can be effectively reduced when the supported placement of sleepers is employed as compared to the suspended placement of sleepers. The interfacial tensile stress at the bottom part of the bonded insulated rail joint under the supported placement of sleepers is increased but the other interfacial stresses are decreased as the thickness of epoxy is increased. When the length of joint bar becomes shorter, the interfacial tensile stress of the bonded insulated rail joint under the supported placement of sleepers is increased significantly but the other interfacial stresses are affected insignificantly. Also, the interfacial stresses of bonded insulated rail joints are higher and more concentrated when the material property of epoxy becomes incompressible.
Book chapters on the topic "Insulated Rail Joints"
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Huang, S. W., S. Burgess, L. Németh Wehrmann, D. Nolan, and Tara Chandra. "Insulated Rail Joints for Signalling Applications." In THERMEC 2006, 4069–74. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.4069.
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Dhanasekar, Manicka, and Kan Ding. "Rolling Contact Fatigue in Rail – Insulated Rail Joints (IRJ)." In Encyclopedia of Tribology, 2910–15. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-0-387-92897-5_292.
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Yuen, Andrew, Dingyang Zheng, Peter Mutton, and Wenyi Yan. "Classification of Impact Signals from Insulated Rail Joints Using Spectral Analysis." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 771–80. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73411-8_61.
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Wei, Zilong, Xiubo Liu, Yu Zhou, Xinyu Jia, and Guoqing Li. "Study on the Initiation of Fatigue Cracks Due to Wheel-Rail Impact at Insulated Rail Joints." In Lecture Notes in Mechanical Engineering, 744–53. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-38077-9_86.
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"Rolling Contact Fatigue in Rail – Glued-Insulated Joints (GIJ)." In Encyclopedia of Tribology, 2910. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-0-387-92897-5_101148.
Full textConference papers on the topic "Insulated Rail Joints"
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Ciloglu, Korhan, Peter C. Frye, Scott Almes, and Sidney Shue. "Advances in Bonded Insulated Rail Joints to Improve Product Performance." In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3746.
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Insulated rail joints (IJs) are critical components of railroad track infrastructure. It is essential for IJs to maintain railroad track’s structural continuity while having an important role in track circuit design and implementation. The structural integrity and performance of IJs have been recognized as a key interest area by the railroads as a result of increasing average axle loads and train traffic. While there are many different designs offered by various manufacturers around the globe, the main approach utilized by heavy haul railroads in the US, Canada and many other countries has been to use adhesively bonded insulated joint bars between two rails. This approach offers the benefit of a composite assembly where the continuous bond between rails and bars offer a geometrically uninterrupted transfer of loads between rails and bars. The main components of a bonded IJ are joint bars, insulation material, adhesive, endpost, and bolts or other fasteners. This paper summarizes recent design improvements on these components. The main focus areas of the research are bar design, bar material selection, insulator and adhesive selection and using a novel endpost design for load transfer between two rails. Track support conditions’ impact on IJ performance has also been considered as a factor influencing IJ performance in track and incorporated in the study. The impact of insulation material selection on IJ performance is discussed. Finite element analysis was used extensively in the study where the analysis results were supported by laboratory and field testing. The results of the study indicate dynamic stresses in bonded IJs can be reduced nearly 40% in joint bars by a combination of design improvements on IJ components. Improved bar material properties are expected to lead to considerably reduced risk of bar fatigue failures in track.
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Holland, Chase C., Thong Q. Do, Robert L. West, and Mehdi Ahmadian. "Insulated Railway Joint Design Methodology Through Parametric Finite Element Based Modeling." In 2010 Joint Rail Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/jrc2010-36022.
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The Railroad Industry experiences multiple failures with currently used bonded insulated joint designs. These failures have encouraged an increased effort in strength and fatigue analysis for the joints. This paper presents a program initiated by Virginia Tech and Transportation Technology Center Incorporated (TTCI) to develop, analyze, and test a family of insulated joint designs featuring non-adhesive bolted connections. This program utilizes a hierarchical set of Finite Element (FE) parametric models that explore the problem’s mechanics for a family of rail joint design concepts by refining the analysis with each subsequent model. Currently, there is limited information concerning design criteria for insulated joints in the Railroad industry. Therefore, an initial task in this program is to define design criteria and representative load cases characteristic of typical life cycles for commercial freight rails. Design criteria are either proprietary to the railroad or do not appear to be published in the AREMA handbooks. However, the AREMA handbooks do define an acceptance test for the failure of rail joint. Failure criteria were derived from the AREMA rolling wheel acceptance test with some modifications to the magnitude of the loads. Using these load cases and design criteria, multiple FE models are used to identify the dominant mechanics of the bolted joint and contact problem. Each model features parametric relationships that enable rapid design changes including geometric features and mechanics. The development of hierarchical FE models facilitates the selection of a specific model that embodies the essential mechanics of the problem while maintaining a geometry that allows for parametric tradeoff studies. The design variables and baseline finite element model are used as an analysis tool developed as an Abaqus scripted template for design comparison studies. The hierarchical approach to finite element modeling with a parametric model has been applied to the development of a bolted insulated rail joint design, which has been realized in a new insulated joint prototype. The mechanics explored in the FE models can be verified using various full-scale load frame tests in a controlled environment. Tests are standardized across models using identical boundary conditions and load cases. The results obtained will be used to confirm modeling assumptions and provide necessary information for further prototype development. The prototype of the full 3-D geometry will be tested in track at TTCI for final design verification. The hierarchical parametric finite element modeling approach results in a tool that can be applied to joint design across the rail industry.
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Iranmanesh, Amir H., Robert L. West, and Mehdi Ahmadian. "Insulated Railroad Joint Design Evaluation by Coordinated Test and Finite Element Analysis." In ASME 2013 Rail Transportation Division Fall Technical Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/rtdf2013-4715.
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The railroad industry faces challenges with bonded insulated joint designs in the present practice. A program initiated by Virginia Tech and the Transportation Technology Center Incorporated (TTCI) has been in progress to analyze and test a class of insulated joint designs featuring non-adhesive bolted connections. A hierarchical approach to finite element modeling with a parametric model maintaining essential mechanics of the joints has been applied to develop a bolted insulated joint design. The current paper reports on the recent phase of the program including development of experimental tests along with finite element analyses on scaled simplified insulated rail joint models. Two baseline rail joint configurations with simplified sections were considered for studying dominant mechanics under the AREMA (American Railway Engineering and Maintenance-of-Way Association) rail joint acceptance standard test loading and boundary conditions. The finite element models developed based on three-dimensional continuum elements incorporated bolt preloads and full-contact analysis. In the experimental tests, the strain analyses on 1/4 scaled polycarbonate rail joint specimens were performed by means of an array of strain gauge transducers mounted on the joint bars and a photoelasticity technique. The results of the experimental stress analyses were employed to validate the finite element models quantitatively and qualitatively in terms of load transfer mechanics and stress distribution. The validated models serve as baseline insulated joint configurations for developing fracture-mechanics-based fatigue-failure analysis. To investigate the role of cracks on the performance and reliability of joint bars, a damage tolerant analysis is performed on the rail joints utilizing linear elastic fracture mechanics. The locations of most critical type defects are estimated based on high stress/strain regions from stress analyses along with past experiences on failure of rail joints. To characterize the severity of theses defects under alternating loading conditions, stress intensity factors are computed as a function of crack length. Cracks of different lengths are introduced in the vicinity of the most fatigue-prone locations of the joint bar in a parametric modeling fashion. The fatigue-crack-growth-rate properties in terms of Paris Law scaling constants are selected from a survey of available material data. The number of loading cycles to failure is obtained by employing the computed stress-intensity factors as well as initial and final crack sizes. Predicted lifetimes as a function of pre-existing crack sizes and geometry of joint configuration can be used as a fracture-mechanics-based function for more accurate design of the rail joints.
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Albakri, Mohammad I., V. V. N. Sriram Malladi, Americo G. Woolard, and Pablo A. Tarazaga. "In-field implementation of impedance-based structural health monitoring for insulated rail joints." In SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, edited by H. Felix Wu, Andrew L. Gyekenyesi, Peter J. Shull, and Tzu-Yang Yu. SPIE, 2017. http://dx.doi.org/10.1117/12.2260050.
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Ryabchik, Tatyana A., Andrey A. Sidrakov, Viktor A. Grechishnikov, Elvira E. Smirnova, and Maksim V. Shevlugin. "The Emergence of Electrical Burning of Insulated Rail Joints in the Moscow Metro." In 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus). IEEE, 2020. http://dx.doi.org/10.1109/eiconrus49466.2020.9039420.
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Ye, Cheng, Liu Zhigang, Huang Ke, and Zhou Hongyi. "Modeling analysis of electric multiple units passing insulated rail joints in high-speed railway station." In 2017 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific). IEEE, 2017. http://dx.doi.org/10.1109/itec-ap.2017.8080757.
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Ryabchik, Tatyana A., Andrey A. Sidrakov, Viktor A. Grechishnikov, Inna S. Kravchuk, and Maksim V. Shevlugin. "The Electrical Burning of Insulated Rail Joints and Its Effects on the Development of Railhead Defects." In 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus). IEEE, 2020. http://dx.doi.org/10.1109/eiconrus49466.2020.9039287.
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Bian, Zheyong, Nathalie Carchi, and Xiang Liu. "A Literature Review on Railroad Tank Car Thermal Protection Systems." In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8099.
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Abstract Railroad tank car transportation is the most efficient way to transport large amounts of hazardous material. More than 2 million tank-car loads of hazardous materials (hazmat) are transported annually by rail in the United States. Recently, the boom in the production of petroleum crude oil and natural gases from shale has dramatically increased the rail transport volume of flammable energy resources. However, accidents do occur, and the transportation of flammable hazardous material can result in disastrous consequences. The fire can heat up a tank car, rapidly increasing the inside pressure and causing the tank car to either rupture or explode. Railroad companies are developing or seeking advanced thermal protection systems to prevent tank car explosion or prolong the burst time to win a sufficient rescue time. It is of great importance to understand the existing thermal protection systems used in hazmat tank cars and to identify key priorities that the government and industry consider for improving tank car thermal protection performance, providing guidance for future thermal protection material development. Thus, this paper reviews the literature on the effects and analysis of different tank car thermal protection systems, identifying the effectiveness of different thermal protection components, properties of thermal protection materials, and testing methodologies. Different combinations of insulators and jackets are tested in order to observe the effects of the fire on the tank car. The tank car is tested while carrying hazardous material like liquefied petroleum gas, propane, and ethylene oxide, etc. This investigation analyzes the differences of thermal protection systems in prolonging the life span of a tank car engulfed in flames. A tank car can use either material like fiberglass, ceramic fiber blankets, perlite powder, or urethane foam to better insulate and thermally protect the tank car. An insulator is shown to prolong the life span of a tank car since bare tank cars tend to heat up rapidly when exposed to flames. The thermal protection system of a tank car is built of insulators, jackets, and supporting material for the insulator. The supporting material and jacket combination with the insulator also prevent the tank car from heating up rapidly. There are two primary testing methods, pool fire, and torch fire. Each type of fire has different outcomes and limits in which the tank car can withstand. When testing the heating of a tank car, thermocouples were placed throughout a tank car and recorded to check what areas were heated the most during the experiment. Some factors that had been accounted for in the previous studies were the wind speed and the direction of the wind, which affected the overall experiment, mostly torch fire experiments.
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Gelman, Vitaly. "Why There Is No IGBT Traction Rectifiers?" In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3802.
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The Insulated Gate Bipolar Transistors (IGBT) are widely used in high power converters. Definite advantages of IGBT rectifiers (also called PWM rectifiers) are: zero reactive power, low harmonics, and inherent power recuperation capability. However stationary traction rectifiers are built with either thyristors or diodes, not with IGBTs. The paper compares IGBT and thyristor rectifiers and analyzes the factors precluding the use of IGBT rectifiers at traction power substations.
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Memon, Saud, and Paul Fromme. "Use of Rail Boot and Collection Mat to Control the Electrolysis of Rail and Utilities in DC Powered Transit Agencies." In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3803.
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Stray current leakage and the corrosion caused by direct current (DC) traction power systems have been an ongoing issue especially in slab/embedded tracks. These tracks typically run through urban traffic areas, city centers, tunnels, and between the utility lines that require the rail to be continuously isolated to provide adequate track-to-earth resistance. Ballasted and direct fixation tracks provide much better track-to-earth resistance when equipped with isolation pads under the rail and exhibit higher stray current protection. Various isolation techniques have been implemented by the DC powered rail transit agencies for the control of track-to-earth resistance in embedded tracks including the use of rail boot. In the last two decades, the practice of rail boot usage has seen a significant increase by transit agencies in the United States for controlling the leakage of current in embedded track sections. However, experience has shown that the rail boot alone cannot always control the stray current leakage and that it is important to supplement the rail boot with additional stray current collection and mitigation techniques. These methods thereby reduce the stray current corrosion by using various combinations of mitigation and collection techniques including, but not limited to, the use of elastomeric grout, insulated rail fasteners, embedding rail in troughs, providing current collection mats, and collector cables. This paper presents and reviews different isolation and/or current collection methods that are presently in use to supplement the rail boot. These current isolation and/or collection methods when implemented together with the rail boot have significantly reduced stray current related problems, including: signal failures, controlling rail-to-earth voltages, minimizing recurring cost of repairs, and the damage to the public infrastructure. Additionally this paper provides general recommendations on the maintenance of the embedded tracks to avoid associated system problems.