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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>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A PROPOSED TRACK PERFORMANCE INDEX FOR CONTROL OF FREIGHT CAR HARMONIC ROLL RESPONSE</title>
      <link>https://trid.trb.org/View/271176</link>
      <description><![CDATA[Analytical and experimental study results of high center of gravity freight car response to a range of track cross-level deviations are presented. Based on the criteria of excessive car body roll or excessive wheel lift, boundaries between safe and unsafe track cross-level conditions are established. These studies and industry experience indicate that although isolated low joints producing crosslevel deviations as large as 4 in. can be safely traversed, at the critical harmonic roll speed, a continuous series of 0.75-in. low joints will produce an unacceptable roll response for high center of gravity cars resulting in a potential derailment. The results also indicate that a 400-ft length of track is sufficient for the harmonic roll resonance to build to a critical amplitude. The cross-level variation conditions that form the boundaries between safe and unsafe harmonic roll response are reviewed. The results are then combined in a heuristically developed performance index that is intended to identify potentially unsafe track conditions without rejecting an excessive amount of track that does not have the potential for producing harmonic roll derailment. Analyses have been conducted on track geometry measurements of selected Class 2 and Class 3 track to evaluate the statistics of the proposed cross-level index. The results indicate that the index does successfully identify potential harmonic roll situations while permitting occasional large cross-level deviations that may be undesirable but are not unsafe. Illustrations of the response of the index to selected measured track geometry conditions are included.]]></description>
      <pubDate>Sun, 31 Jul 1988 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/271176</guid>
    </item>
    <item>
      <title>PROCEEDINGS INTERNATIONAL CONFERENCE ON WHEEL/RAIL LOAD AND DISPLACEMENT MEASUREMENT TECHNIQUES JANUARY 19-20, 1981</title>
      <link>https://trid.trb.org/View/201560</link>
      <description><![CDATA[Measurement of wheel/rail characteristics generates information for improvement of design tools such as model validation, establishment of load spectra and vehicle/track system interaction.  Existing and new designs are assessed from evaluation of vehicle/track degradation and performance measure associated with dynamic behavior, fuel economy and safety parameters.  Diagnosis and verification of hypotheses dealing with carbody hunting, rock and roll, wheel climb, wear and rail strength have been instrumental in introduction of new types of trucks such as the radial and self-steering designs.  Advancement in the field of wheel/rail load and displacement measurement have been achieved by organizations all over the world. This conference provided a look at international developments in the current state-of-the-art.  From papers presented, it is evident that instrumented wheelsets for load measurement have reached an advanced stage of sophistication.  Accuracy and frequency response of commonly used sets are adequate for most dynamic studies and for assessment and diagnosis of existing or new equipment.  Because an instrumented wheelset is generally delicate and complicated with its sophisticated electronics and associated data recording systems, future developments should emphasize simplification and reduced costs.  Wayside load measurement has seen the TSC/Battelle lateral circuit and the ORE vertical circuit receive wide acceptance. Direct comparison of on-board and wayside measured loads has provided added confidence in both methods.  Rail motion can be monitored at wayside, but there has been little development of measurement of wheel motion relative to rail.  It is expected that there will be rapid advancements in measurement of wheel/rail interaction.  This conference should hasten such development.]]></description>
      <pubDate>Thu, 28 Jun 1984 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/201560</guid>
    </item>
    <item>
      <title>STABILITY OF NATURAL SIDEWAYS VIBRATIONS IN WAGONS</title>
      <link>https://trid.trb.org/View/172976</link>
      <description><![CDATA[As is well-known, with the conical treads of railway wheelsets, uneven sideways movements occur as the vehicle moves forward.  This article compares the conventional approach to the phenomenon resulting from research over the past 15 Years and describes vehicles designed during recent research and the corresponding mechanical calculations.]]></description>
      <pubDate>Wed, 28 Oct 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/172976</guid>
    </item>
    <item>
      <title>VIBRATION TEST UNIT CONTROL AND COMPUTER SYSTEM</title>
      <link>https://trid.trb.org/View/165416</link>
      <description><![CDATA[The Vibration Test Unit (VTU) is designed to vibrate a railcar to simulate the action of track/train dynamics using a hydraulic shaker system.  Studies of suspension characteristics, rock and roll tendencies of rail vehicles, component and vehicle natural frequencies, ride comfort, lading responses, and simulation of full scale vehicle inputs at each wheel/rail interface and lateral inputs along each axle line at the rail/wheel interface.  The VTU uses a dual minicomputer system for signal generation, data acquisition, and limit checking.]]></description>
      <pubDate>Sat, 15 Aug 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/165416</guid>
    </item>
    <item>
      <title>DESIGNING PERTURBED TEST TRACKS FOR EVALUATING RAIL VEHICLE DYNAMIC PERFORMANCE</title>
      <link>https://trid.trb.org/View/164899</link>
      <description><![CDATA[Perturbed tracks provide a controlled means for evaluating the performance of rail vehicles in various dynamic modes, such as hunting, rock-and-roll, pitch-and-bounce, yaw-and-sway, and dynamic curving. This paper describes a systematic approach for designing such tracks and illustrates the methodology as it has been applied to the preliminary design of the tangent and curved perturbed tracks for the Stability Assessment Facility for Equipment (SAFE), which is being developed under the auspices of the Government-Industry Track Train Dynamics Program.]]></description>
      <pubDate>Thu, 09 Jul 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/164899</guid>
    </item>
    <item>
      <title>EVALUATION OF NON-LINEAR FLEXIBLE CARBODY VEHICLE (FREIGHT CAR) MODEL</title>
      <link>https://trid.trb.org/View/164754</link>
      <description><![CDATA[The Non-linear Flexible Carbody Vehicle Model, that was developed to study the dynamic behavior of a freight car travelling on tangent track, was evaluated using field test data.  A description of the model, data acquisition and data reduction for validation is presented.  Five car configurations, corresponding to different auxiliary suspension devices, were used for comparisons between the model results.  While a good correlation was obtained for some configurations, it was found that better data on the characteristics of some devices is still needed.]]></description>
      <pubDate>Fri, 12 Jun 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/164754</guid>
    </item>
    <item>
      <title>PARAMETRIC STUDY OF A LARGE CAPACITY RAILROAD FREIGHT VEHICLE SUSPENSION</title>
      <link>https://trid.trb.org/View/161031</link>
      <description><![CDATA[A mathematical model of a railroad freight vehicle is presented.  The model is constructed in such a way to describe the rock sway and bounce modes of the system and also to account for most of the nonlinearity effects experienced by the system.  Time and frequency responses evaluated from the model are compared with the available measured data to establish the validity of the mathematical model.]]></description>
      <pubDate>Mon, 19 Jan 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/161031</guid>
    </item>
    <item>
      <title>VOLUME III--SUSPENSION DYNAMICS: USE OF AUXILIARY SUSPENSION DEVICES</title>
      <link>https://trid.trb.org/View/157209</link>
      <description><![CDATA[This report is the final volume of an extensive supsension dynamics parametric study, conducted during Track-Train Dynamics-Phase II.  It supplements the two previous reports: R-224 and R-350, published by the Association of American Railroads Technical Center, Chicago, Illinois.  The purpose of the study reported in this volume was to evaluate the effects of auxiliary suspension devices on the attenuation of freight car rock and roll motions.  Two cars, a 100-ton covered hopper and a 100-ton open-top hopper, were studied in the investigation.  The suspension devices studied included constant-contact side bearings; rubber pads, located between the carbody and truck bolsters; and two hydraulic units, A and B, located below the truck bolster in the suspension spring group.]]></description>
      <pubDate>Tue, 30 Dec 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/157209</guid>
    </item>
    <item>
      <title>DYNAMIC ROCKING RESPONSE AND OPTIMIZATION OF THE NONLINEAR SUSPENSION OF A RAILROAD FREIGHT CAR</title>
      <link>https://trid.trb.org/View/154789</link>
      <description><![CDATA[A modified mathematical model of a large capacity railroad freight vehicle is presented.  The model for this investigation is constructed in such a way to describe the bounce, sway and rocking modes of the system and also to account for most of the vehicle nonlinearity effects. Equations of motion of the six degree of freedom nonlinear model are derived assuming that the excitations from the track in vertical and lateral directions are purely periodic in the form of a rectified sine wave.  The solution for the time and frequency responses on digital computer are compared with available measured data to investigate the model accuracy.  Multivariable optimization techniques are employed to find the optimum suspension parameters that minimizes the maximum rocking response over the frequency range of interest.  The optimum parameters are presented in different forms either for the existing or for stabilized vehicle configuration.]]></description>
      <pubDate>Tue, 16 Sep 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/154789</guid>
    </item>
    <item>
      <title>MATHEMATICAL MODELING OF DODX RAILCARS</title>
      <link>https://trid.trb.org/View/155967</link>
      <description><![CDATA[This report presents the results of a project conducted to determine the roll stability characteristics of large capacity freight cars, 100 to 200 ton, loaded with high center of gravity containers.  The model, obtained from AAR, is a 22 degree-of-freedom, non-linear, time domain model of railcars equipped with two axle trucks.  The model was modified to include hydraulic dampers, an improved Coulomb friction damping model, and a track input to simulate perturbed track specified in AAR specification D-65.  Also a lower order integration technique and a larger integration technique and a larger integration stepsize were employed to reduce computer run time.  The model was validated against each of four vehicles on which full scale field tests had been conducted.  In three of the four cases sufficient agreement was found between the results of the model and those of the field test to proceed with further simulations of other load/suspension configurations.  Results of these simulations suggest that improvement in roll stability can be achieved by reducing the vehicle suspension spring rate or similarly increasing the load.  It was also found that one of the vehicles studied possessed a dead band in the stroke of the hydraulic stabilizer.  By modifying this stabilizer to operate over the full stroke, vehicle dynamic performance should show improvement.]]></description>
      <pubDate>Tue, 16 Sep 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/155967</guid>
    </item>
    <item>
      <title>HARMONIC ROLL RESPONSE OF A RAILROAD FREIGHT CAR</title>
      <link>https://trid.trb.org/View/150245</link>
      <description><![CDATA[A mathematical model of a railroad freight car has been developed under the Track-Train Dynamics Program.  The model simulates a car equipped with auxiliary suspension devices (e.g., rubber-cushion type or viscous dampers) under various perturbed track conditions.  The study compares the model predictions with test data and demonstrates the application of the model in studies of various auxiliary suspension devices for controlling the harmonic roll response and component loadings of a railroad freight car.]]></description>
      <pubDate>Wed, 27 Aug 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/150245</guid>
    </item>
    <item>
      <title>FIRST ORDER DYNAMIC RESPONSE OF FREIGHT CAR TO TRACK IRREGULARITIES</title>
      <link>https://trid.trb.org/View/150248</link>
      <description><![CDATA[This paper offers a review of simple dynamic response of the freight car suspension to track irregularities, the resultant effect on lading and energy feed back to the track structure.]]></description>
      <pubDate>Wed, 27 Aug 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/150248</guid>
    </item>
    <item>
      <title>RESPONSE ANALYSES OF A BOXCAR WITH COMPLIANT LADING FOR SEVERAL TRACK PROFILE AND HUNTING CONDITIONS</title>
      <link>https://trid.trb.org/View/150806</link>
      <description><![CDATA[The simulation in the FRATE computer program (Freight Car Response Analysis and Test Evaluation) was modified from a flexible TOFC (trailer on flatcar) to a rigid boxcar with compliant lading. Analyses were performed to obtain the response of boxcar elements and compliant lading to several track profile and body hunting conditions. Three types of track profile irregularities were simulated: (1) a single vertical irregularity on both rails, (2) a single vertical irregularity on one rail and (3) rectified sine representations of staggered joint bolted rail. Hunting conditions were simulated by imposing sinusoidal lateral motions at the wheel rail interface. Worst case conditions resulted in wheelrail separations and in potentially damaging accelerations of the lading.]]></description>
      <pubDate>Tue, 05 Aug 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/150806</guid>
    </item>
    <item>
      <title>TOFC (TRAILER ON FLATCAR) LADING RESPONSE ANALYSES FOR SEVERAL TRACK PROFILE AND HUNTING CONDITIONS</title>
      <link>https://trid.trb.org/View/150809</link>
      <description><![CDATA[The computer program FRATE is a non-linear, time domain digital computer program developed under Federal Railroad Administration sponsorship for the purpose of studying freight car response dynamics. The trailer on flatcar (TOFC) simulation contained in FRATE was expanded, for the purposes of the analyses of this report, to include a compliant lading representation. The compliant lading consisted of two spring mounted masses in each trailer with vertical, lateral and roll degrees of freedom. Analyses were performed to obtain the response of the TOFC vehicle and compliant lading to several track profiles and body hunting conditions. The analysis results characterize the response of a standard TOFC configuration to typical service conditions. Undesirable response conditions are noted and recommendations are made for improvements.]]></description>
      <pubDate>Tue, 05 Aug 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/150809</guid>
    </item>
    <item>
      <title>TRACK STRUCTURES-VOLUME IV. EFFECTS OF TRACK GEOMETRY (IRREGULARITIES) ON THE DYNAMIC BEHAVIOR OF A RAILWAY VEHICLE ON TANGENT TRACK</title>
      <link>https://trid.trb.org/View/149472</link>
      <description><![CDATA[The objective of this report is to evaluate the effects of various track irregularities on the dynamic behavior of railway vehicles moving over tangent track which meets the FRA standards.  Two different freight cars are used for the study.  The peak to peak roll angle of the carbody, center plate loads, wheel loads and accelerations are investigated for different track errors and combinations thereof.  It is found that track classification according to irregularities and speed limit is not appropriate.  This type of classification does not identify the severity of dynamic loads to which the track and vehicle components are subjected.  Also, in some cases vehicles will perform better at speeds greater than the specified limit and are subjected to undesirable conditions when operated within the speed limit.]]></description>
      <pubDate>Wed, 21 May 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/149472</guid>
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