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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Influence of creep force modelling on the non-linear stability of a rail vehicle on tangent and curved tracks</title>
      <link>https://trid.trb.org/View/2329572</link>
      <description><![CDATA[Past works have shown that the application of the non-Hertzian wheel/rail contact in the multibody system simulation may produce non-negligible differences in the results compared to the results obtained using the classical Hertzian approach. As a continuation of this research line, the running stability of a passenger rail vehicle running on tangent and curved tracks has been investigated considering the wheel/rail creep force being determined using Hertzian and non-Hertzian approaches, respectively. The results show that the creep force modelling has varied levels of influence on the estimation of the stability of a rail vehicle on both tangent and curved tracks depending on the non-ellipticity of the contact. The non-Hertzian model is recommended to be used for such kind of applications as the traditional Hertzian approach may misestimate the dynamics behaviour of the vehicle under certain circumstances.]]></description>
      <pubDate>Mon, 11 Mar 2024 15:56:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2329572</guid>
    </item>
    <item>
      <title>On the use of transmissibility for the detection of damaged springs in the primary suspension of a locomotive</title>
      <link>https://trid.trb.org/View/2329571</link>
      <description><![CDATA[The condition monitoring of the suspensions of railway vehicles is of utmost importance, allowing the reduction of the maintenance actions and the increase in the operational safety. However, the available methods often require a simplification of the vehicle through linearised models, a high number of sensors, or the use of complex algorithms that disregard the mechanical phenomena that explain the vehicle dynamics. This work suggests the Localized Transmissibility Damage Indicator (LTDI), based on the existing Transmissibility Damage Indicator (TDI), to detect damage in the springs of a locomotive, using pairs of sensors placed in the bogie frame and the axle boxes. For that purpose, multibody simulations are used to simulate the dynamic behaviour of the vehicle in tangent tracks under nominal and damaged conditions. The results from multibody simulations allow the calculation of the LTDI values for different levels of damage and various operation conditions, as well as the study of the effect of the variability inherent to the railway operation. The results show that the LTDI is significantly sensitive to damage. However, depending on the use of the lateral or vertical response, the LTDI is more suitable to detect the stiffness increase or decrease, or even to locate the damage. In conclusion, the LTDI is a promising method for the detection of damage on suspension elements of railway vehicles.]]></description>
      <pubDate>Mon, 11 Mar 2024 15:56:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2329571</guid>
    </item>
    <item>
      <title>Alignment Tolerance of Rail Tracks</title>
      <link>https://trid.trb.org/View/1735668</link>
      <description><![CDATA[The alignment of a railroad affects the ride quality most. It is necessary to keep the track irregularities at a bare minimum for safe, and comfortable riding. The significant track parameters are alignment, surface, and gauge. The scope of the paper is limited to alignment tolerance for construction and maintenance. The aim of the paper is to develop a theoretical approach to assess the alignment tolerance of both tangent and curved track for construction and maintenance purposes. The approach is based on comfort criterion on jerk. Currently, there is no such work in literature. Some formulas are suggested for construction and maintenance tolerance of tangent and curved track. The formulas are applied and validated against the current tolerance values from literature, EN specification, federal railroad authority (FRA) regulation, and real-world examples. The paper would offer insights on tolerance values and would be useful for professionals.]]></description>
      <pubDate>Thu, 17 Sep 2020 17:54:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1735668</guid>
    </item>
    <item>
      <title>Dynamics of an isolated railway wheelset with conformal wheel–rail interactions</title>
      <link>https://trid.trb.org/View/1656205</link>
      <description><![CDATA[In multi-body dynamics, the authors model a non-conformal wheel/rail contact at one centre point since this contact is flat and Hertzian. However, the quasi-conformal contact requires more points since the contact is curved and non-Hertzian. The methodology in solving these points during dynamic simulations is the basis of this development. In this online effort, first, the authors present a general contact joint and the gutter search method of Pascal and Jourdan [The rigid-multi-Hertzian method as applied to conformal contacts. USA: ASME; 2007] in the context of a multi-body approach. Next, by adopting the non-iterative approach, a subset of these points with positive profile interpenetrations is selected to idealise one curved contact by a set of multi-Hertzian patches for which the Hertz normal contact solution is available. Finally, the feasibility of this multibody approach together with its implementation in two different codes is evaluated by simulating the motion of an isolated wheelset with realistic inertia. On tangent tracks, the wheelset with non-conformal pairing displays self-excited unstable oscillations while it displays a stable behaviour below a critical speed with conformal profiles. A further study reveals the net friction losses at multiple patches within the curved contact being the reason for the stable behavior.]]></description>
      <pubDate>Fri, 22 Nov 2019 16:48:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1656205</guid>
    </item>
    <item>
      <title>Effect of Hollow-Worn Wheels on Wheel and Rail Interaction with North American Freight Cars</title>
      <link>https://trid.trb.org/View/1539910</link>
      <description><![CDATA[This report examines the effect that hollow-worn wheels have on wheel and rail interaction for typical North American freight cars on tangent and curved track. Hollow wear tends to reduce the speed at which hunting starts and can increase the rail roll moment. However, hollow wear is not the sole controller of wheel and rail interaction. Other important factors include rail shape, wheel flange wear, track gages, and wheel back-to-back spacing.]]></description>
      <pubDate>Thu, 27 Sep 2018 15:12:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1539910</guid>
    </item>
    <item>
      <title>Analysis of coupler jackknifing and its effect on locomotives on a tangent track</title>
      <link>https://trid.trb.org/View/1511475</link>
      <description><![CDATA[Coupler jackknifing has caused a number of derailments, and it is a significant topic that needs in-depth studies. This paper aims to investigate the characteristics of coupler jackknifing and its effects on the dynamic performance of locomotives during braking. A field braking experiment using three eight-axle locomotives was conducted on a tangent track. The experimental results indicated that in-service couplers with a friction arc surface are prone to coupler jackknifing once the compressive force of the coupler exceeds 400?kN. After coupler jackknifing, the coupler angle has a significant positive correlation with the yaw angle of the car body; both coupler jackknifing and coupler angle increase rapidly to maximum values. The contact between the car body and the bogie seriously affects the dynamic performance of the locomotive and causes lateral instability of the locomotive. In particular, the lateral deviation of the coupling couplers generates an eccentric wear on the tail of the coupler. A numerical simulation model is developed to investigate the effect of coupler jackknifing on the running safety of the locomotive. Simulation results show that coupler jackknifing induces an excessive lateral force on the wheelset and increases the risk of derailments and gauge widening. Compared with the existing measures against coupler jackknifing, in this study, an effectively active measure is proposed to improve the stability of the coupler and to prevent possible derailments caused by coupler jackknifing during braking.]]></description>
      <pubDate>Mon, 21 May 2018 17:11:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1511475</guid>
    </item>
    <item>
      <title>On the overriding issue of train front end collision in rail vehicle dynamics</title>
      <link>https://trid.trb.org/View/1501638</link>
      <description><![CDATA[A three-dimensional dynamic model of crashed vehicles coupled with moving tracks is developed to research the dynamic behaviour of the train front end collision on tangent tracks. The three-dimensional dynamic model consists of a crashed vehicle model, moving track models, a simple wheel–rail contact model, a velocity-based coupler model and the model of energy absorption and anti-climbing devices. The vector method dealing with the nonlinear wheel–rail geometry is put forward in the paper. The developed model is applicable in the scope that central collisions occur on tangent tracks at low speeds. The examples of the vehicle impacting with a rigid wall and the train front end collision are carried out to obtain the dynamic responses of vehicles. The overriding issue is studied on the basis of the wheel rise in train collisions. The results show that the second bogie of the first colliding vehicle possesses the maximal wheel rise. The wheel rise increases with the increase of vehicles. However, the number of vehicles has tiny influence on the overriding in train collisions at low speeds. On the contrary, the impact speed has significant influence on the overriding in train collisions. The wheel rise increases rapidly if the impact speed is close to the critical speed of overriding. The large wheel rise is principally generated by the great coupler force related to the rigid impact in the axial direction.]]></description>
      <pubDate>Thu, 22 Mar 2018 12:03:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501638</guid>
    </item>
    <item>
      <title>Wheel Slide Protection System by the Use of the Tangential Force in the Macro Slip Area</title>
      <link>https://trid.trb.org/View/1481103</link>
      <description><![CDATA[Almost all railway vehicles have brake systems which use the tangential force between rails and wheels. It is difficult to stabilize braking performance and to prevent wheel damage because the tangential force is influenced by various conditions, such as weather, the contact surfaces of the rails and the wheels, etc. Wheel slide protection systems (WSP) are one solution adopted on many vehicles. However, in existing WSP systems, braking force is controlled using limited information from the rotational speed of the wheel. Therefore, they do not always offer optimal control when the tangential force varies frequently. This study proposes a new WSP system which can determine the quality of the tangential force from the brake cylinder pressure when wheel slips occur. The performance of the new WSP was verified through bench tests. As a result, application of the new WSP method reduced braking performance loss.]]></description>
      <pubDate>Wed, 30 Aug 2017 16:57:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1481103</guid>
    </item>
    <item>
      <title>Effective Radius at the Tangent Point and Its Uses</title>
      <link>https://trid.trb.org/View/1412350</link>
      <description><![CDATA[The aim of the paper is to estimate the effective (functional) radius at the tangent point, and to demonstrate its use to compute the track construction tolerances and speed on a non-spiraled curve. The existence of lateral acceleration at transition point between tangent and curved track indicates that the radius at the tangent point must have some functional finite value. The effective radius is estimated by using the principle adopted in BS EN 13803-2:2006 to determine the effective radius at the switch point of a turnout placed on a tangent track. A method is suggested to estimate the construction tolerance of a new track and speed on a non-spiraled curve from the concept of the effective radius. The concept of effective radius seems to have useful applications.]]></description>
      <pubDate>Thu, 30 Jun 2016 17:23:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1412350</guid>
    </item>
    <item>
      <title>Coupler jackknifing and derailments of locomotives on tangent track</title>
      <link>https://trid.trb.org/View/1266922</link>
      <description><![CDATA[A number of derailments occurred in recent years due to coupler jackknifing. Some of them were reported on tangent tracks, conventionally thought to be the safer sections. This article studied coupler jackknifing behaviour and its implications for locomotive safety on tangent tracks from the experience of China heavy haul. Three types of coupler systems were modelled and simulated regarding coupler jackknifing behaviour. Two typical locomotive derailments occurring on tangent tracks were analysed. From the derailment experience, coupler angle self-lock behaviour was introduced and simulated. An approach to determine coupler angles in the jackknifed position was derived and validated with a self-coded program and SIMPACK. Methods to prevent coupler jackknifing were also evaluated with regard to locomotive stability.]]></description>
      <pubDate>Thu, 21 Nov 2013 09:21:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1266922</guid>
    </item>
    <item>
      <title>Stability Analysis of High-Speed Railway Vehicle using Half-Car Model</title>
      <link>https://trid.trb.org/View/920595</link>
      <description><![CDATA[A dynamic model of a railway vehicle moving on tangent tracks is developed in this article. The governing differential equations of motion for a 12-degree of freedom (DOF) half-car system are derived with the incorporation of lateral and yaw movements of each wheel set, the lateral and vertical displacements, and the roll and yaw movements of the truck frame and the half-car body. The effects of physical parameters on critical hunting speeds in the 6-DOF, 8-DOF and 12-DOF models are also investigated in the article. The effect of certain physical parameters, which were not considered in the 6-DOF model, is investigated for wheels of different conicities.]]></description>
      <pubDate>Mon, 19 Jul 2010 11:34:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/920595</guid>
    </item>
    <item>
      <title>Simulations of roughness growth on rails – results from a 2D non-Hertzian, non-steady contact model</title>
      <link>https://trid.trb.org/View/850743</link>
      <description><![CDATA[A new model for simulating rail roughness growth on tangent track is presented in this paper. The model consists of three relatively independent components: (1) a time-domain vehicle/track interaction model; (2) a 2D non-Hertzian and non-steady wheel/rail contact model; and (3) a wear model. Wheel/rail contact forces for a given initial roughness obtained from the vehicle/track interaction model are used by the contact model to calculate the contact patch size, normal pressure and tangential stresses with material removal assumed to be linearly proportional to the friction work in the contact patch. The roughness profile is updated and fed back into vehicle/track interaction model. The 2D contact model is initially compared with a 3D model for various wavelength of initial sinusoidal roughness. Long term roughness growth is then simulated with the 2D contact model. Simulation shows that all initial sinusoidal roughness of wavelengths between 20–100 mm are levelled out. The wavelength-fixing mechanism, that has previously been used to explain the cause of corrugation, is not found in the present investigations.]]></description>
      <pubDate>Thu, 27 Mar 2008 10:28:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/850743</guid>
    </item>
    <item>
      <title>REFINING THE WHEEL/RAIL INTERFACE</title>
      <link>https://trid.trb.org/View/711677</link>
      <description><![CDATA[Wheel and rail technologies have developed and converged so much that it is now possible for railroads to fully control wheel and rail profiles.  Improved control leads to benefits ranging from improved safety due to a reduction in wheel and rail damage and reduced maintenance costs from longer wheel and rail life.  The article discusses how tighter control of wheel and rail profiles offers a variety of performance benefits for both rolling stock and infrastructure.  Some of the benefits include improved vehicle steering in tangent and curved track, leading to lower wheel/rail forces, and reduced wheel/rail stresses leading to less wear and rolling contact fatigue.]]></description>
      <pubDate>Tue, 14 May 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/711677</guid>
    </item>
    <item>
      <title>WHEEL AND RAIL VIBRATION ABSORBER TESTING AND DEMONSTRATION</title>
      <link>https://trid.trb.org/View/686750</link>
      <description><![CDATA[This report will be of interest to engineers responsible for wheel/rail noise control in the design, construction, and operation of rail transit systems.  It provides the results of field tests performed at two light rail transit systems to demonstrate the effectiveness of wheel and rail vibration absorbers in reducing rolling noise on tangent track and wheel squeal on curved track.  Testing of wheel and rail vibration absorbers was conducted at the Tri-County Metropolitan Transportation District of Oregon (Tri-Met).  The wheel and rail vibration absorbers were tested individually, and in combination, on both tangent and curved track.  Wheel vibration absorbers were also field tested on tangent and curved track at the New Jersey Transit Corporation's Newark subway system.]]></description>
      <pubDate>Tue, 12 Jun 2001 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/686750</guid>
    </item>
    <item>
      <title>EXACT TANGENT STIFFNESS FOR IMPERFECT BEAM-COLUMN MEMBERS</title>
      <link>https://trid.trb.org/View/659532</link>
      <description><![CDATA[The exact tangent and secant stiffness matrices of an initially curved beam-column element under predominant axial force and end moments are derived.  The stability function of solving the differential equilibrium equation for the beam-column element is further extended to allow for the important effect of member initial imperfection.  The accuracy of this developed element makes the convergence rate for equilibrium and resistance against divergence better than that by the conventional cubic element or other currently available elements.  The use of a single element per member is adequate enough for the extreme case of a column with both ends fixed, in which even two cubic elements cannot generate an accurate result.  As a single element can sufficiently model a member, the second-order analysis, the nonlinear integrated design and analysis, and the advanced analysis become simple, reliable, and easy to use for practical design.  The present element can also be used as a benchmark element for second-order elastic analysis of two- and three-dimensional frames and represents the ultimate solution for the imperfect element under Timoshenko's beam-column theory.]]></description>
      <pubDate>Wed, 20 Sep 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/659532</guid>
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