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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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>SUBSURFACE STRESS EVALUATIONS UNDER ROLLING/SLIDING CONTACTS</title>
      <link>https://trid.trb.org/View/277552</link>
      <description><![CDATA[A computer model has been developed for evaluating the subsurface stresses incurred within rolling/sliding (elastic) contacts.  The model involves first defining the stress tensor at any point (x, y, or z) beneath the surface in terms of the surface stresses.  The stress tensors are analyzed to determine the maximum shear stresses and stress reversals.  As a result of computations with the model, several observations were made.  For example, the maximum reversing shear stresses are on the plane of the orthogonal shear stress.  Further, the magnitude of these stresses is not altered by friction.  However, under very high friction (typical of dry contact) surface stresses can dominate over subsurface stresses.]]></description>
      <pubDate>Sat, 28 Aug 2004 04:48:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/277552</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF AN AUTOMATED STEERING VEHICLE BASED ON ROADWAY MAGNETS : A CASE STUDY OF MECHATRONIC SYSTEM DESIGN</title>
      <link>https://trid.trb.org/View/639007</link>
      <description><![CDATA[In this paper, the authors describe the process involved in developing an automated steering control system for the California PATH Program. The process consists of the following steps: determining control objectives, defining system structure, validating vehicle dynamics developing a lateral sensing system, designing a steering actuator installing a test track, developing a control algorithm, integrating software and hardware, and vehicle testing.]]></description>
      <pubDate>Wed, 16 Feb 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/639007</guid>
    </item>
    <item>
      <title>A LATERAL POSITION SENSING SYSTEM FOR AUTOMATED VEHICLE FOLLOWING</title>
      <link>https://trid.trb.org/View/510589</link>
      <description><![CDATA[In this paper, the authors study the use of photoresistive light sensor arrays as a possible lateral position sensing system for a vehicle or vehicles following a lead vehicle under separate control. The sensing arrays and sensor layouts are described, and their benefits are discussed.  These include cost, simplicity, redundancy and near linearity.  The paper presents experimental results for a scaled vehicle following maneuver using a simple lateral control strategy]]></description>
      <pubDate>Wed, 17 Nov 1999 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/510589</guid>
    </item>
    <item>
      <title>SPECTRAL CORRELATION TECHNIQUES APPLIED TO EVALUATE NOISE AND SAFETY TRADEOFFS IN TIRE/PAVEMENT INTERACTION</title>
      <link>https://trid.trb.org/View/270670</link>
      <description><![CDATA[Relationships between pavement surface geometry, truck tire sound, and skid number are investigated to provide an understanding of the tire/pavement interaction mechanism.  Correlation techniques are used to determine the relationship between each pair of the three parameters.  Results show 1) the relationship between pavement profile and truck tire sound as a function of frequency, 2) a positive relationship between pavement profile spectral amplitudes, and pavement skid number, and 3) no significant relationship existing between truck tire sound and skid number.]]></description>
      <pubDate>Fri, 31 Jan 1986 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/270670</guid>
    </item>
    <item>
      <title>IDENTIFICATION OF VEHICLE AND COLLISION IMPACT PARAMETERS FROM CRASH TESTS</title>
      <link>https://trid.trb.org/View/270671</link>
      <description><![CDATA[In the mid 1970s a group of 12 staged and instrumented automobile collisions was conducted for the National Highway Traffic Safety Administration.  These were two-vehicle collisions with a variety of initial speeds, vehicle orientations, and vehicle size mixes.  Initial speeds were controlled and velocity components including angular velocities at separation were measured.  At about the same time, development of the classic theory of impact of rigid bodies to planar vehicle collisions was taking place.  Users of classic theory heretofore had neglected the existence of a moment between impacting bodies.  Inclusion of a moment and introduction of a moment coefficient of restitution allows the formulation of a planar collision model consisting of six algebraic equations relating the six initial velocity components of the two vehicles to their six final velocity components.  The model contains collision geometry, vehicle geometry, vehicle inertial properties, and three coefficients.  These coefficients are the classic coefficient of restitution, a friction coefficient, and the newly defined moment coefficient.  This paper discusses the application of the theory of least squares to fit the experimentally determined velocity components to the six equations of the vehicle collision model. The usual approach using the theory of least squares is to set to zero the partial derivatives of the sum of squares taken with respect to the unknowns.  The original model equations can be added as constraints through the use of Lagrange multipliers.  A set of 15 nonlinear algebraic equations results.  This approach was tried unsuccessfully.  Direct numerical minimization of the sum of squares using gradient projection techniques proved to be far superior.  Solutions are obtained for the staged collisions.  Results provide insight into velocity changes and their relationships to energy dissipation, the coefficients of restitution and friction and other collision parameters.  The capability of calculating velocity changes of colliding vehicles should prove complementary to detailed finite element studies of vehicle crush properties.]]></description>
      <pubDate>Fri, 31 Jan 1986 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/270671</guid>
    </item>
    <item>
      <title>EFFECT OF PROTECTIVE HELMET MASS ON HEAD/NECK DYNAMICS</title>
      <link>https://trid.trb.org/View/182085</link>
      <description><![CDATA[The crash helmet which provides protection against injury due to direct head impact may actually contribute to injury in indirect head impact (e.g., hyperflexion or "whiplash") situations because of the added mass of the helmet on the head/neck system. It has been suggested that it may be possible to reduce this hyperflexion/hyperextension injury hazard while retaining the beneficial protection against direct impact through use of helmet restraining collars, such as styrofoam or inflatable airbags. These claims are quantitatively and qualitatively examined and discussed in this paper. The UCIN HEAD/NECK computer simulation model is used for the quantitative analysis. It is shown that the helmet can indeed contribute to the hyperflexion/hyperextension injury hazard and that the proposed restraining devices can potentially provide protection against this hazard.]]></description>
      <pubDate>Sat, 30 Oct 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/182085</guid>
    </item>
    <item>
      <title>RAIL VEHICLE ACTIVE SUSPENSIONS FOR LATERAL RIDE AND STABILITY IMPROVEMENT</title>
      <link>https://trid.trb.org/View/180777</link>
      <description><![CDATA[The potential performance benefits of simple, low power active elements in the lateral secondary, between the truck and carbody is investigated analytically by parametric studies utilizing a fifteen degree of freedom lateral model subject to alignment and cross-level inputs.  It is shown that significant improvements in ride quality can be obtained at current operating speeds by using less than 3 kw per truck by sensing lateral carbody accelerations and utilizing lateral force actuators between the truck and carbody.  It is concluded that significant ride quality improvements can be achieved by low power, small bandwidth actuators while stability improvement requires increased power and larger bandwidth systems.]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180777</guid>
    </item>
    <item>
      <title>MAGNETIC GUIDANCE OF CONVENTIONAL RAILROAD VEHICLES</title>
      <link>https://trid.trb.org/View/180778</link>
      <description><![CDATA[The potential for improved dynamic performance of conventional rail vehicles through control of linear induction or synchronous motors is explored.  Improvements in vehicle stability, ride quality, traction capability, track loading, derailment safety, and curving performance results from use of controllable lateral and normal forces present in the motor.  Recent advances in technology originally developed for high-speed levitated vehicles are applied to conventional railroad systems which have a greater potential for near-term implementation.  The dynamic performance of alternate configurations, consisting of several generic motor types mounted either on trucks or car bodies, are evaluated.]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180778</guid>
    </item>
    <item>
      <title>NONLINEAR STABILITY AND TRACKING OF RAIL PASSENGER TRUCKS</title>
      <link>https://trid.trb.org/View/180779</link>
      <description><![CDATA[An analysis of a rail passenger truck which includes nonlinear wheel/rail geometry and creep forces is formulated for determining truck stability and response to rail alignment irregularities.  Digital simulation studies using the analysis have illustrated the large amplitude flange to flange response which occurs in operation of a truck below critical speed on a track with significant alignment irregularity, of a truck near critical speed and excited by irregularities and of a truck operated obove critical speed. The variations in temporal waveform, probability density and power spectral density of vehicle motions for these conditions are described.  The influence of vehicle suspension parameters and wheel/rail geometry on truck stability and tracking ability is discussed and related to operating conditions.]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180779</guid>
    </item>
    <item>
      <title>ACCELERATION DETECTION AND INERTIA COMPENSATION OF PANTOGRAPH HEAD USING A CONSTANT FLOW HYDRAULIC SERVO</title>
      <link>https://trid.trb.org/View/180780</link>
      <description><![CDATA[The paper presents a novel form of acceleration detection which is suitable for use in hydraulic amplification stages for relatively low frequency, high power output servo systems.  The acceleration detector was developed as part of a research program concerned with the development of a servo assisted pantograph to provide improved current collection on high speed electrified railways.]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180780</guid>
    </item>
    <item>
      <title>TESTING A TRANSIT VEHICLE FOR WHEEL AND RAIL WEAR</title>
      <link>https://trid.trb.org/View/180785</link>
      <description><![CDATA[A test program was undertaken to investigate whether modifications to the track design, particularly a reduction of the primary longitudinal stiffness, would reduce wheel and rail wear on a new rapid transit system.  The test program examined the behavior of the trucks during the negotiation of a number of curves typical of those encountered in revenue service.  Test results compared favorably with predictions from a mathematical model of the truck's curving behavior and, subsequently, the model was used to evaluate a number of truck parameter variations. The paper quantifies the effects of axle misalignment and discusses the need for experimental data to relate wear index to wheel and rail wear.]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180785</guid>
    </item>
    <item>
      <title>A LOW SENSITIVITY MODERN APPROACH TO THE LONGITUDINAL CONTROL OF AUTOMATED TRANSIT VEHICLES</title>
      <link>https://trid.trb.org/View/39157</link>
      <description><![CDATA[Modern control and estimation techniques are applied to the design of longitudinal controllers for automated transit vehicles. The sensitivity of dynamic response to changes in vehicle parameters and the effects of noisy sensors on control system performance are studied. A method for sensitivity reduction by augmentation of the state vector with the sensitivity vector is proposed and low sensitivity design is developed which provides excellent dynamic response over a wide range of operating conditions and vehicle parameters. /Author/]]></description>
      <pubDate>Wed, 15 Jul 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/39157</guid>
    </item>
    <item>
      <title>THE ROLE OF FRACTURE MECHANICS IN DESIGN TECHNOLOGY</title>
      <link>https://trid.trb.org/View/66501</link>
      <description><![CDATA[Fracture mechanics has in recent years become an independent discipline that deals with determining the conditions under which machine or structural elements attain uncontrollable failure by crack propagation.  A knowledge of these conditions can assist the designer to safeguard structures against catastrophic fracture.  In contrast to the conventional approach, which does not account for flaws initiated in the material by manufacturing procedures, overloads, or fatigue loadings, fracture mechanics assumes that all materials contain cracks from which failure starts. This concept has been used successfully for high-strength/low- toughness materials design and for structures that exhibit brittle behavior.  Obtained from laboratory specimes loaded symmetrically with respect to the crack plane is a critical stress intensity factor parameter k sub 1,.  It is a characteristics of the material commonly referred to as the fracture toughness value.  When machine elements are subjected to combined loading, where symmetry does not exist, the direction of crack initiation is no longer known as an a priori.  The condition of crack instability can then be predicted from the strain energy density factor S.  Numerous numerical examples involving press fit, rotating disk, thermally stressed pipe, pressure vessel, etc., are presented to show how fracture mechanics can be used for estimating the load that a member can sustain without causing unstable fracture.  The results are compared with those obtained from the conventional design approach whenever possible.]]></description>
      <pubDate>Wed, 16 Feb 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/66501</guid>
    </item>
    <item>
      <title>NONLINEAR WHEELSET DYNAMIC RESPONSE TO RANDOM LATERAL RAIL IRREGULATITIES</title>
      <link>https://trid.trb.org/View/26916</link>
      <description><![CDATA[The nonlinear equations of motion for a railway vehicle wheelset having profiled wheels and contact of the wheel flange with flexible rails are presented.  The effects of spin creep and gyroscopic terms are included.  The rails are considered to have random lateral irregularities which are described by prescribed power spectra.  The equations of motion are integrated numerically and the effects on the dynamic response of quantities such as speed, track roughness, wheel wear, flange clearance, and lateral stiffness of the rails are investigated.]]></description>
      <pubDate>Fri, 02 Jul 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/26916</guid>
    </item>
    <item>
      <title>ON THE STRUCTURAL DESIGN OF TUBULAR JOINTS</title>
      <link>https://trid.trb.org/View/39792</link>
      <description><![CDATA[Stresses in thin-walled tubular joints can be calculated with finite-element computer programs that employ "thin-shell" elements.  Such a program, designated SATE, has been developed specifically with the object of determining stress distributions in complex tubular joints as generally encountered in the offshore industry.  The program has been applied to several joint geometries and good agreement has been observed between experimental and calculated results. The program thus provides insight into the structural design of tubular joints.  Using the SATE program, the influence of changes in design of both unstiffened and stiffened tubular joints on the stress-concentration factor has been studied. In this context, the current API recommendations for simple tubular joint design are discussed.  Calculations have demonstrated that in the design of large tubular joints, allowance should be made for membrane action rather than for bending of the chord and brace walls.  Such an approach leads to joints of low stress concentration. /AUTHOR/]]></description>
      <pubDate>Tue, 29 Jul 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/39792</guid>
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