LATEST ARTICLES
Details of the latest articles published in the Journal. Includes the most recent InPress papers (uncorrected proofs of accepted papers awaiting publication in a Journal issue).
Date: Wed, 18 Aug 2010 14:45:09 GMT
The article presents an extensive survey of experimental data on rolling contact fatigue (RCF) crack shape and propagation characteristics in rails removed from service, where such cracks are angled to the rail axis. The data include re-analysis of previously published experimental data to extract crack shape information and new experimental work on crack shapes at different stages in the early RCF life. Periods from initiation (ratcheted ‘flake cracks’) have been considered through very early growth to the limit of one prior austenite (PA) grain and on to rail-head visual cracks. Techniques included multi-sectioning through single cracks and crack zones, on used rail and test discs, to build up real three-dimensional (3D) data on crack shapes and propagation characteristics. This data have been compared with the UK rail system guidance charts relating to visual crack length and respective vertical depth; all data fell within the indicated guidance zones. The configuration of such angled cracks, typically found in curves, so aligned due to the vector of both lateral and longitudinal traction, rather than just axially, was identified as an important case for modelling. A fracture mechanics-based model has been developed to predict modes I and II stress intensity factors for such cracks covering multiple PA grains. An important geometry effect is revealed by which a contact approaching a crack angled to the rail axis is effectively ‘offset’ from the approach direction considered in 2D models, thereby resulting in lower predicted peak stress intensity factor values, compared with 2D, for the prediction of crack growth rates.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT414
- Authors
- J E Garnham, School of Metallurgy and Materials, University of Birmingham, UK
- D I Fletcher, Department of Mechanical Engineering, University of Sheffield, UK
- C L Davis, School of Metallurgy and Materials, University of Birmingham, UK
- F J Franklin, School of Mechanical and Systems Engineering, University of Newcastle upon Tyne, UK
Date: Wed, 18 Aug 2010 14:45:08 GMT
Long-range ultrasonic testing (LRUT) uses guided waves in the kilohertz range to inspect many metres of an elongated component from a single point of access. This has considerable advantages for the rapid testing of long lengths for the detection of potentially harmful defects. This technique is well developed for structures that have a simple geometry, such as plates, rods, and pipes. However, this is a relatively new technology and there is still much to learn about the behaviour of guided waves and their application in complex structures, such as railway rails. The aim of this work was to identify suitable ultrasonic-guided wave modes that can detect common types of defects in each part of a rail (i.e. the head, web, and foot). The investigation was carried out using finite-element analysis and was validated experimentally. The findings of this research demonstrated the ability to detect transverse defects as small as 2 mm and 5 mm in the head and foot, respectively.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT413
- Authors
- Y Gharaibeh, TWI, Granta Park, Great Abington, Cambridge, UK
- R Sanderson, TWI, Granta Park, Great Abington, Cambridge, UK
- P Mudge, TWI, Granta Park, Great Abington, Cambridge, UK
- C Ennaceur, TWI, Granta Park, Great Abington, Cambridge, UK
- W Balachandran, School of Engineering and Design, Brunel University, Uxbridge, Middlesex, London, UK
Date: Wed, 18 Aug 2010 14:45:08 GMT
Undergrounds and other metropolitan railway systems are characterized by their intense traffic, lasting up to 20 h per day, and so they need their maintenance work programmes to be optimized, implying an optimization of the monitoring processes. This article proposes an alternative to the traditional optical methods for monitoring rail profiles which can only be carried out by special vehicles. This is a new procedure that obtains the rail profile by means of inertial methods. The model this work is based on takes its input from the vertical accelerations produced in railway axles measured in trains running on regular services and calculates the rail irregularities that have originated them. The model uses the Fourier transform in order to solve the equations and find the transfer function that relates the input function and the output function in the frequency domain. The solution is then reverted into the time domain by applying the inverse Fourier transform. Data input comes from real measurements taken on line 9 of the Madrid underground, and the model's effectiveness was then analysed by comparing the output data with the rail profile taken using optical methods.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT353
- Authors
- J Real
- P Salvador
- L Montalbán
- M Bueno
Date: Wed, 18 Aug 2010 14:45:08 GMT
This article is concerned with the role of innovation in cost reduction and the mechanisms for bringing it about. In the first section, it investigates the efficiency of UK's railways through the medium of cost benchmarking of both UK and continental European costs. It finds that British rail infrastructure costs appear to be some 40 per cent higher than implied by European best practice, and that train operating costs have also risen substantially, both because of rising factor prices (wages and fuel) and because of deteriorating productivity. It then explores the situation surrounding incentives for shaping technological innovation through a series of semistructured interviews with senior managers representing a wide range of railway interests. This section highlights the presence and successful functioning of the commercial mechanism for technology development in the industry both through natural commercial factors and through mechanisms such as track access charges. Finally, it studies the feasibility of modelling systems subject to technological change, with the aim of creating a methodology to assess, at an early stage in the development cycle, the physical impact innovation might have on the existing system. It finds that the objective data needed to construct such models can be extracted from existing technical standards and that systems engineering techniques provide a suitable framework for structuring and linking that data.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT383
- Authors
- C Bouch, Birmingham University, UK
- C Roberts, Birmingham University, UK
- K Lovell, Imperial College London, UK
- C Griffiths, Imperial College London, UK
- R Smith, Imperial College London, UK
- C Nash, University of Leeds, UK
- A Smith, University of Leeds, UK
- P Wheat, University of Leeds, UK
Date: Wed, 18 Aug 2010 14:45:08 GMT
A number of measurements of particle emission from railways are presented. The measurements featured a particle instrument mounted in a compartment under a Regina train. The particles were probed in a volume between the coaches. The measurements were done in two campaigns and provide information on how the particle emissions vary with driving patterns.
The measurements showed elevated particle concentrations when the train was running. Further, sharp peaks in the particle concentration were observed. It was noted that these peaks coincided with retardation of the train. However, there are also retardations where no peaks were observed. This can be explained from the two parallel breaking systems, one with regenerative breaking and one with mechanical breaks that are present on the Regina train. The authors suggest that the observed peaks coincide with the use of the mechanical breaks. It was not possible to fully establish that increased particle concentration coincides with curvature of the rail, even though this was indicated in parts of the data.
The size-resolved data showed maxima for the smallest fraction (350 nm) for the number distribution.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT407
- Authors
- E Fridell, IVL Swedish Environmental Research Institute, Göteborg, Sweden
- A Björk, IVL Swedish Environmental Research Institute, Göteborg, Sweden
- M Ferm, IVL Swedish Environmental Research Institute, Göteborg, Sweden
- A Ekberg, CHARMEC/Chalmers Industrial Technology, Chalmers University, Göteborg, Sweden
Date: Mon, 02 Aug 2010 18:41:30 GMT
Guest Editorial
- Content Type Journal Article
- Authors
Date: Thu, 29 Jul 2010 16:56:47 GMT
Mechatronic technologies are increasingly adopted on railway vehicles, with particular reference to active secondary suspensions, as a means to improve vehicle performance in terms of ride safety and quality. This article presents the results of a theoretical and experimental research aimed at introducing active control capabilities in the pneumatic secondary suspension of a high-speed railway vehicle. The active airspring suspension is used, together with an active lateral suspension, to reduce passengers’ exposure to lateral acceleration in curves and to improve ride safety with respect to vehicle overturning in the presence of extreme crosswind. In this article, the active airspring concept is developed and suitable open- and closed-loop control strategies are developed. Then, the results of an experimental characterization of the active suspension are reported, and based on these results a mathematical model of the vehicle with active suspension is defined. Finally, the active suspension performance is demonstrated by means of numerical experiments, showing the potential to bring substantial benefits in terms of both higher service speed for the same cant deficiency sensed by the passengers and increased ride safety.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT392
- Authors
- S Alfi
- S Bruni
- G Diana
- A Facchinetti
- L Mazzola
Date: Thu, 29 Jul 2010 16:56:46 GMT
In the major railway accidents in GB that have occurred in the past 10 years it became increasingly apparent that a significant number of fatalities and serious injuries had arisen as a result of passengers being thrown out through the vehicle windows. This article describes the work that has been carried out to establish the circumstances related to passenger ejection and the performance of existing glazing systems. It then considers the consequences of making passenger vehicle windows more resistant, both in terms of better containment and any detrimental effects on using the windows as potential escape routes or as a means of access by emergency services. The final part of the work was to produce a specification that would give the desired improvement in safety performance and to establish a practical method of performance demonstration by testing.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT388
- Authors
- R Nowell, Rolling Stock Engineer, Rail Safety and Standards Board, London, UK
- A Sutton, Independent Consultant, Derby, UK
Date: Thu, 29 Jul 2010 16:56:46 GMT
When standing and exposed to vibration in trains, passengers and crew may seek support by leaning on a surface or holding a bar or a handle that alters the transmission of vibration to their bodies. The effects of such contact on the discomfort caused by vibration have not been previously investigated. This study was designed to investigate the effects of postural supports on the discomfort caused by fore-and-aft and lateral whole-body vibration in the frequency range 0.5–16 Hz. Using the method of magnitude estimation, 12 standing male subjects judged the discomfort caused by five magnitudes of sinusoidal vibration at six frequencies (0.5, 1.0, 2.0, 4.0, 8.0, and 16 Hz) and in two directions (fore-and-aft or lateral) while using four different postural supports: no support, holding a vertical bar, leaning with back support, and leaning with shoulder support. Equivalent comfort contours were constructed, showing how discomfort depends on the vibration frequency over a range of vibration magnitudes with each support. Compared to standing with no support, holding a vertical bar had only a minor effect on the discomfort caused by either fore-and-aft or lateral vibration. At frequencies greater than about 2 Hz, leaning backwards against a back support increased the discomfort caused by fore-and-aft vibration and leaning sideways against a shoulder support increased discomfort caused by lateral vibration. Frequency weightings corresponding to the equivalent comfort contours were constructed and show that the weightings suggested in current standards do not provide good predictions of the frequency dependence of discomfort caused by vibration when standing without any support or when supported and holding only a bar. It is concluded that leaning, with the back or shoulder supported, increases the discomfort caused by vibration in a direction normal to the body surface at frequencies greater than about 2 Hz. Currently, standardized frequency weightings do not provide good predictions of the discomfort caused by horizontal vibration when standing without holding a support.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT369
- Authors
Date: Thu, 29 Jul 2010 16:56:46 GMT
The increasing demand of long and interoperable freight trains requests suitable numerical simulators of train longitudinal dynamics. Focusing attention on the European railway freight transport, such simulators need to properly model the typical Union Internationale des Chemins de Fer (UIC) pneumatic brake, even for more than one active locomotive placed along the train. A pneumatic model, previously developed, has been integrated in a software for longitudinal train dynamics (TrainDy). This software has been successfully subjected to an international process of validation and certification, undertaken by an ad hoc expert group on behalf of UIC. By using TrainDy, UIC plans to update the actual limits of the UIC leaflet 421. Moreover, UIC has established a consortium dedicated to further improve the code. This article outlines the main features of the simulator along with the most significant results of its validation process.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT347
- Authors
Date: Thu, 29 Jul 2010 16:56:45 GMT
Whole-body vibrations in trains are known to affect the performance of sedentary activities such as reading, writing, sketching, working on a computer, etc. The objective of the study was to investigate the extent of disturbance perceived in sketching task by seated subjects in two postures under mono- and multi-axis Gaussian random vibration environment. The study involved 21 healthy male subjects in the age group of 23–32 years. Random vibrations were generated both in mono- and multi-axial directions in the frequency range of 1–10 Hz at 0.5, 1.0, and 1.5 m/s2 RMS (root mean square) amplitude. The subjects were required to sketch given geometric figures such as a circle, triangle, rectangle, and square with the help of ball-point pen under given vibration stimuli in two postures (sketch pad on lap and sketch pad on table). The deviation in distortion with respect to the given figure is represented in terms of percentage distortion. The influence of vibrations on the sketching activity was investigated both subjectively and by two specifically designed objective methods, namely, RMS and area methods. The judgements of perceived difficulty to sketch were rated using seven-point semantic judgement scale. The percentage distortion and difficulty in sketching activity increased with an increase in vibration magnitude. Both subjective evaluation and the RMS method revealed that the task was affected more while sketching on the table. The percentage distortion was affected similarly and maximum in all the vibration directions except for the vertical, while sketching difficulty was found to be higher only with longitudinal and multi-axis vibration direction. The subjective evaluation also revealed that there was no effect of the type of entity chosen on the sketching difficulty.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT336
- Authors
- M K Bhiwapurkar, Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarkhand, India
- V H Saran, Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarkhand, India
- S P Harsha, Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarkhand, India
- V K Goel, Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarkhand, India
- M Berg, Department of Vehicle Engineering, Royal Institute of Technology, Stockholm, Sweden
Date: Mon, 19 Jul 2010 16:14:52 GMT
Electric railways collect power from the infrastructure via various current collection systems. For high-VOLTAGE AC- and DC-powered railways, this is usually achieved using overhead electrification equipment and a train-borne pantograph. The dynamics of such systems are well understood, and the systems are able to be operated under a range of conditions and speeds. Lower-voltage DC-powered railways (<1500 V) use a current collecting shoe as part of a shoegear system and track side electrification infrastructure in the form of a conductor rail. The dynamics of such systems are equally as complex as those of overhead systems. This is due to the interaction between the conductor rail and the track system, coupled with the dynamics of the conductor shoe assembly, which are mechanically linked with the bogie and axle systems. The systems also collect high currents (<2000 A), and therefore maintaining an effective electrical contact is essential. The interface between the conductor shoe and conductor rail is regulated through standards and guidelines. However, there are numerous engineering challenges in the effective management of the whole system that have yet to be addressed. The mechanical design of the system must balance the requirements of good fatigue life with appropriate impact strength. Other issues such as removal of contaminants from the conductor rail surface and shoe wear also have an impact on the design.
This article presents some experimental results from a bogie-mounted instrumentation system designed to monitor a typical example of a shoegear assembly operated on the UK railway system. The results indicate that the shoegear broadly performs in accordance with the design guidelines. Several points of loss of contact were observed, and it is shown that the contact force between the conductor shoe and rail can be estimated. The mean force was found to vary with third rail height, but a wide distribution of forces is found at any one height because of hysteresis in the shoegear. Large, but short-term, forces and torques occur because of third rail irregularities and ramps.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT401
- Authors
- E Stewart
- P Weston
- S Hillmansen
- C Roberts
Date: Mon, 19 Jul 2010 16:14:51 GMT
Vertical wheel–rail contact forces with high magnitudes are generated in vehicle operation on track sections with periodic (rail corrugation) or discrete (rail joints, crossings) surface defects and/or in operations with out-of-round wheels. This may result in severe wheel damage, such as subsurface rolling contact fatigue and deep shelling. Based on input data in the form of contact forces measured by an instrumented wheelset, including contributions with frequencies up to about 2 kHz, a track condition analyser (TCA) has been developed. The dominating and most frequently occurring types of rail rolling surface defects can be detected, their location along the line can be determined, and their detrimental effect on the fatigue life of wheels can be estimated. This means that the TCA can be used as a tool to assess the current track quality and determine the need for immediate and planned track maintenance. Using the instrumented wheelset on a Swedish passenger train, the 450 km line Stockholm–Gothenburg can be measured in both directions during an 8 h test campaign.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT398
- Authors
- P Gullers, Interfleet Technology AB, Solna, Sweden
- P Dreik, Dreik Ingenjörskonst AB, Stockholm, Sweden
- J C O Nielsen, Department of Applied Mechanics/CHARMEC, Chalmers University of Technology, Gothenburg, Sweden
- A Ekberg, Department of Applied Mechanics/CHARMEC, Chalmers University of Technology, Gothenburg, Sweden
- L Andersson, Interfleet Technology AB, Solna, Sweden
Date: Mon, 19 Jul 2010 16:14:51 GMT
Design and standardization of railway axles from the mechanical-strength point of view is discussed and a brief state-of-the-art survey is given. Traditional fatigue design with the ‘safe-life’ approach and a design with the more recent crack-propagation/defect-tolerance approach are described and compared. Axles of a standard freight wheelset (22.5 tonne axle load) and of two heavy haul wheelsets (25 and 31 tonne axle loads) are used for illustration. From the numerical results it is concluded that a crack-propagation/defect-tolerance approach could be a useful complement to the traditional fatigue design method. A result of particular interest is the fairly strong influence of stresses from the press-/shrink-fitting on the residual life of the axles.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT384
- Authors
- R Lundén, Department of Applied Mechanics, Chalmers University of Technology/CHARMEC, Göteborg, Sweden
- T Vernersson, Department of Applied Mechanics, Chalmers University of Technology/CHARMEC, Göteborg, Sweden
- A Ekberg, Department of Applied Mechanics, Chalmers University of Technology/CHARMEC, Göteborg, Sweden
Date: Mon, 19 Jul 2010 16:14:50 GMT
Vehicle braking in non-electrified rail systems wastes energy. This article considers two approaches to reducing braking losses in regional diesel trains: efficient driving strategies and regenerative braking. The interaction of these two approaches is critical in specifying the requirements of a hybrid train and assessing the relative fuel saving. Computational models of conventional and hybrid diesel-hydrodynamic regional trains have been developed using real route data to generate a simple control algorithm and investigate the effect of driving strategy on fuel consumption and journey time. The current modelling predicts fuel savings of up to 40 per cent for the hybrid train when an aggressive control strategy is used. This fuel saving is halved when an efficient driving strategy is employed, which also reduces the required energy storage capacity. The model provides a tool for identifying effective control strategies which should be implemented to reduce fuel consumption for both conventional and hybrid trains.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT374
- Authors
- M G Read
- C Griffiths
- R A Smith
Date: Mon, 19 Jul 2010 16:14:50 GMT
Head checking (HC) as a surface-initiated rolling contact fatigue damage on rails has been a problem for many railways. Countermeasures such as optimal design of wheel and rail profiles, optimal design of the vehicle–track interaction system, HC-resistant rail materials, etc. are being developed. Such development requires a better understanding of the relationship between the operational loading conditions of the rails and the initiation of HC. This article presents an effective non-Hertzian method for evaluating the stress state on the rail and wheel surfaces under operational conditions, so that HC initiation, location, and orientation can be directly related to the stress. It is shown that the HC initiation location and orientation derived from the computed stress state are in agreement with those observed in the field.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT368
- Authors
- R Dollevoet, Infra Management Railsystems, Department of Civil Technology, ProRail De Inktpot, Utrecht, The Netherlands
- Z Li, Section of Road and Railway Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, The Netherlands
- O Arias-Cuevas, Section of Road and Railway Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, The Netherlands
Date: Mon, 19 Jul 2010 16:14:49 GMT
This article presents a qualitative comparison of the key characteristics and subsequent impact performance between articulated and non-articulated train types. The fundamental purpose of the article is through a review of articulated and non-articulated trains in terms of impact stability to identify and compare the areas referable to ‘impact worthiness’ design.
The major differences between articulated and non-articulated trains are highlighted first. Then, the mechanical reasons leading to the differences and their consequences to impact performance are analysed from three viewpoints: coupling stiffness and freedom, support and coupling patterns, and carbody structural features. The analysis shows that the differences in bogie support positions on the carbody and the effects on coupling devices lead to differences in several structural and compositional characteristics, including height of gravity of the carbody, length of the vehicle, the composition of the end panel, stiffness of coupling device, number of support points to vehicle, and support height of the secondary suspension.
These characteristics result in different impact responses for the two types of train and are directly related to subsequent behaviour. Articulated trains show stiff connection and integral performance in collisions but with less capability for absorbing impact energy between vehicles, whereas non-articulated trains show flexible connection with more random behaviour in collisions but with greater options for energy absorber installation between vehicles.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT303
- Authors
- X Xue, School of Computing and Mathematical Sciences, University of Greenwich, London, UK
- S Ingleton, NEWRAIL – University Rail Research Centre, Newcastle University, Newcastle upon Tyne, UK
- J Roberts, Bombardier Transportation, Crespin, France
- M Robinson, NEWRAIL – University Rail Research Centre, Newcastle University, Newcastle upon Tyne, UK
Date: Mon, 19 Jul 2010 16:14:49 GMT
In this article, a two-degrees-of-freedom model for the disc brake system is set up by considering the vertical motion of the brake unit and the pitch motion of the bogie frame, and the sliding friction interface between the brake lining and disc is included in the model. Using the Hurwitz determinants, an algebraic criterion for determining the Hopf bifurcation point of the system is proposed. The vehicle speed at the Hopf bifurcation point is defined as the critical speed where the equilibrium position of the disc brake system loses stability and the limit cycle emerges. In order to investigate the stability of the disc brake system, parametric studies are undertaken. It is shown that the mass of brake unit, vertical damping of primary suspension, friction coefficient, and brake normal force between the lining and disc have significant influences on the critical speed. The instability of the system may not occur if the parameters are properly designed. The limit cycle arisen due to the loss of stability of the equilibrium position is studied using the numerical integration method. It is found that once the brake system loses its stability at a certain speed, the stick–slip motion occurs and the limit cycle oscillation will last until the vehicle comes to a standstill. It is also known that the frequency of limit cycle is significantly affected by the mass and suspended stiffness of the brake unit but is not related to the vehicle speed in the braking process.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT307
- Authors
Date: Wed, 30 Jun 2010 16:39:32 GMT
To ensure the safe and efficient operation of the approximately 1.6 million freight cars (wagons) in the North American railroad network, the United States Department of Transportation (USDOT), Federal Railroad Administration (FRA) requires periodic inspection of railcars to detect structural damage and defects. Railcar structural underframe components, including the centre sill, sidesills, and crossbearers, are subject to fatigue cracking due to periodic and/or cyclic loading during service and other forms of damage. The current railcar inspection process is time-consuming and relies heavily on the acuity, knowledge, skill, and endurance of qualified inspection personnel to detect these defects. Consequently, technologies are under development to automate critical inspection tasks to improve their efficiency and effectiveness. Research was conducted to determine the feasibility of inspecting railcar underframe components using machine vision technology. A digital video system was developed to record images of railcar underframes and computer software was developed to identify components and assess their condition. Tests of the image recording system were conducted at several railroad maintenance facilities. The images collected there were used to develop several types of machine vision algorithms to analyse images of railcar underframes and assess the condition of certain structural components. The results suggest that machine vision technology, in conjunction with other automated systems and preventive maintenance strategies, has the potential to provide comprehensive and objective information pertaining to railcar underframe component condition, thereby improving utilization of inspection and repair resources and increasing safety and network efficiency.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT376
- Authors
- B W Schlake, Railroad Engineering Program, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Civil Engineering Laboratory, Urbana, Illinois, USA
- S Todorovic, School of EECS, Oregon State University, Kelly Engineering Center, Corvallis, Oregon, USA
- J R Edwards, Railroad Engineering Program, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Civil Engineering Laboratory, Urbana, Illinois, USA
- J M Hart, Department of Electrical and Computer Engineering, Computer Vision and Robotics Laboratory, University of Illinois at Urbana (Champaign), Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- N Ahuja, Department of Electrical and Computer Engineering, Computer Vision and Robotics Laboratory, University of Illinois at Urbana (Champaign), Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- C P L Barkan, Railroad Engineering Program, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Civil Engineering Laboratory, Urbana, Illinois, USA
Date: Wed, 30 Jun 2010 16:39:32 GMT
This article investigates the effect of vertical track stiffness, and its variations along the track, on track performance with focus on dynamic responses of the track due to parametric excitations. Two approaches for calculating global track stiffness, a static one based on Zimmermann's theory and a dynamic one based on the track model used in the dynamic vehicle–track interaction program DIFF, are discussed. A rolling stiffness measurement vehicle has been developed at Banverket, and measurements have been carried out over hundreds of kilometres of track. This article presents a statistical analysis of the collected results and provides information of track stiffness and its variation on typical Swedish tracks.
- Content Type Journal Article
- DOI 10.1243/09544097JRRT361
- Authors