<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <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>
    </image>
    <item>
      <title>Computer Simulation in Real Time Rail Traffic Control</title>
      <link>https://trid.trb.org/View/2691560</link>
      <description><![CDATA[This thesis examines the use of computer-based dispatcher assist systems for real-time rail traffic control on heavily used single-track rail lines. It focuses on the problem of planning train meets and passes so that total delay is minimized while supporting dispatcher decision-making. The study evaluates methods for predicting point-to-point train running times and analyzes operating data to measure the variability of actual train performance. The results show that train running times are highly variable, and that this uncertainty must be incorporated directly into dispatching logic. Building on this finding, the thesis develops local and global optimization procedures for meet planning, including methods that account for train priorities, running times, acceleration penalties, and uncertainty in future arrivals. A branching procedure is also presented to search alternative meet-pass strategies and identify minimum-delay solutions under uncertain conditions. The thesis concludes that computerized dispatcher assist can improve rail line efficiency when it provides accurate, flexible, and interactive support rather than rigid automatic control, and it includes FORTRAN code implementing the proposed algorithms in the appendix.]]></description>
      <pubDate>Sun, 26 Apr 2026 17:38:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691560</guid>
    </item>
    <item>
      <title>Understanding of Pavement Profiling and Validation of an Implementation</title>
      <link>https://trid.trb.org/View/2263776</link>
      <description><![CDATA[Understanding of pavement profiling and roughness is critical for a pavement engineer to evaluate pavement serviceability and performance. This paper presents the principles of pavement profiling, roughness, and measurement. The report also discusses International Roughness Index (IRI), widely used by pavement engineer to assess the pavement condition. In the process of learning pavement profiling, a program code in C language was written to perform the calculation of the roughness index for a given profile. The C code in this report is largely based on the available FORTRAN code. In the process of writing the coding and validating the computer program, much better understanding was gained of how pavement profiles and dynamic mechanics are used for the calculation of International Roughness Index. The report concludes with the validation of the C code and a discussion on the application of interval in calculating IRI values.]]></description>
      <pubDate>Mon, 24 Feb 2025 14:46:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2263776</guid>
    </item>
    <item>
      <title>A Finite-Element Method of Solution for Structural Frames</title>
      <link>https://trid.trb.org/View/2431695</link>
      <description><![CDATA[An efficient numerical method of solution to structural frame problems is presented. The method is shown to be applicable to no-sway, plane-frame structures that may derive part or all of their support from soils. A finite-element model composed of bars and springs is used to represent groups of orthogonal frame members. Finite-difference equations written for this model are solved by a previously developed recursive method. Individual beams are solved alternately in the two orthogonal directions and at each joint a relaxation technique is used to adjust the two solutions and achieve rotational compatibility. A complete listing of the FORTRAN computer program is included, plus two example problems illustrating the applicability of the method.]]></description>
      <pubDate>Sat, 21 Sep 2024 16:56:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2431695</guid>
    </item>
    <item>
      <title>A Finite-Element Method of Solution for Linearlly Elastic Beam-Columns</title>
      <link>https://trid.trb.org/View/2427468</link>
      <description><![CDATA[A wide spectrum of beam and beam-column problems can be described and solved by a single computer method. A finite mechanical analog is employed to allow very general loading and elastic restraint conditions to be considered. The resulting system of equations is solved by a rapid and efficient direct elimination process. Program BMCOL 34 and associated input forms and instructions are applied to the solution of a series of highway-type example problems. Complete listing of the FORTRAN program is given, plus input and output data for the examples.]]></description>
      <pubDate>Mon, 16 Sep 2024 10:31:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2427468</guid>
    </item>
    <item>
      <title>Wave Equation Analysis of Pile Driving WEAP Program: Volume IV - Narrative Presentation</title>
      <link>https://trid.trb.org/View/2213655</link>
      <description><![CDATA[A computer program was written and tested that performs a realistic Wave Equation Analysis of Piles driven by any type of impact hammer. Conventional pile and soil models were used in addition to both a thermodynamic model for diesels and refined mechanical hammer models. The program development was aimed at providing a simple input and both a flexible and extensive output that includes automatic plotting capabilities. Pile Driving Hammer data were prepared and stored in a file for most of the commonly encountered models. The computer language is FORTRAN 4. The program was extensively tested against measured pile top force and velocity data and against measured diesel combustion pressure and stroke. This volume is the fourth in a series.]]></description>
      <pubDate>Tue, 18 Jul 2023 12:53:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2213655</guid>
    </item>
    <item>
      <title>Effect of track flexibility on fatigue life of railway concrete slab track</title>
      <link>https://trid.trb.org/View/2151766</link>
      <description><![CDATA[Although reduction of fastening system stiffness and interlayer stiffness are two main approaches to increase the track flexibility, it is not obvious which one has a greater effect on decreasing the fatigue life of the concrete slab in different conditions. This research was carried to eliminate this limitation. In this regard, a numerical model of vehicle/slab track interaction was developed in the FORTRAN environment and a code was written in MATLAB to calculate the fatigue life of concrete slab based on the compressive and tensile stresses, Miner’s rule and a proper concrete fatigue life model. Through a parametric study, the effects of different parameters such as concrete slab thickness, concrete compressive strength, vehicle speed and vehicle axle load on the influences of rail-pad and interlayer stiffness on the fatigue life of concrete slab were investigated. The results obtained from the parametric study were summarized in contour figures to find a proper strategy to simultaneous increase in the railway track flexibility and the fatigue life. It was shown that decreasing the rail-pad stiffness and increasing the interlayer stiffness leads to simultaneous increase in the flexibility and fatigue life of railway concrete slab track. It was found that the track flexibility and fatigue life reach an acceptable level when the rail-pad and interlayer stiffness is lower and greater than 60 and 2500 MN/m, respectively.]]></description>
      <pubDate>Thu, 25 May 2023 13:52:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2151766</guid>
    </item>
    <item>
      <title>A Numerical Method for Estimating the Deflections of Ballasted Railway Tracks</title>
      <link>https://trid.trb.org/View/1705463</link>
      <description><![CDATA[This paper presents a method to estimate the deflection in ballasted railway tracks and compares the results with field measurements, performed by other researchers. The influence of different variables on deflection estimation such as loading, gauge, rails, sleepers, layers’ thickness and resilient modulus was parameterized through 768 simulations of representative layered structures using the finite-element software ABAQUS. It is not about conventional numerical simulations, but simulations implementing a theoretical-empirical model developed in Brazil, with Brazilian soils from different regions, by Guimarães (2009) in their Ph.D thesis. For this implementation, an internal subroutine named UMAT, from ABAQUS, was developed in Fortran. With the deflections results from each simulated track, a matrix with 768x7 elements was formed and solved with a MATLAB program. As a result, an equation was defined to estimate deflections of real railway tracks similar to those simulated. Comparisons among the numerical simulation results and field tests show that the proposed method can be applied to predict vertical displacement of railway tracks.]]></description>
      <pubDate>Tue, 26 May 2020 17:26:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1705463</guid>
    </item>
    <item>
      <title>Mechanical modeling of deepwater flexible structures with large deformation based on absolute nodal coordinate formulation</title>
      <link>https://trid.trb.org/View/1667841</link>
      <description><![CDATA[In this paper, a mechanical analysis model is proposed on basis of the absolute nodal coordinate formulation (ANCF) and the theories of continuum mechanics and finite element method to accurately analyze the statics and dynamics of deepwater flexible structures with large deformation. In this model, the traditional angle coordinate is replaced with slope coordinate under the frame of overall coordinate system. The mapping relation of the parameters under current and reference configurations is established, and the method of describing the nonlinear geometric relationship of the element with the current configuration parameters is discussed. Then, based on the energy variation principle, the generalized elastic force and stiffness matrix of the element are derived, and the mass matrix and external load matrix of the element are combined to perform the element assembling using the finite element method, and the static and dynamic equilibrium equations are then formed. The calculation programs are compiled by FORTRAN language, whose reliability and accuracy are checked by the cases of beam model with theoretical solutions. Finally, a kind of steel lazy wave catenary riser is taken as an example, and its static and dynamic characteristics are analyzed systematically, which further verifies the effectiveness and practicability of the mechanical model.]]></description>
      <pubDate>Fri, 20 Dec 2019 16:24:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1667841</guid>
    </item>
    <item>
      <title>Aerodynamic Optimization Based on Continuous Adjoint Method for a Flexible Wing</title>
      <link>https://trid.trb.org/View/1434759</link>
      <description><![CDATA[Aerodynamic optimization based on continuous adjoint method for a flexible wing is developed using FORTRAN 90 in the present work. Aerostructural analysis is performed on the basis of high-fidelity models with Euler equations on the aerodynamic side and a linear quadrilateral shell element model on the structure side. This shell element can deal with both thin and thick shell problems with intersections, so this shell element is suitable for the wing structural model which consists of two spars, 20 ribs, and skin. The continuous adjoint formulations based on Euler equations and unstructured mesh are derived and used in the work. Sequential quadratic programming method is adopted to search for the optimal solution using the gradients from continuous adjoint method. The flow charts of rigid and flexible optimization are presented and compared. The objective is to minimize drag coefficient meanwhile maintaining lift coefficient for a rigid and flexible wing. A comparison between the results from aerostructural analysis of rigid optimization and flexible optimization is shown here to demonstrate that it is necessary to include the effect of aeroelasticity in the optimization design of a wing.]]></description>
      <pubDate>Mon, 21 Nov 2016 13:42:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1434759</guid>
    </item>
    <item>
      <title>Regression of the Recovery Rate of ACM Rubber Gasket for Long-Term Performances</title>
      <link>https://trid.trb.org/View/1409456</link>
      <description><![CDATA[An engine head cover gasket in automobile engines is constantly exposed to high temperature and pressure conditions. The life time of an engine head cover gasket is important due to the increasing demand for more reliable automobile parts. The main failure mechanism of rubber gaskets, which is the aging due to temperature, can be determined using standard test equipment. The highly accelerated life test (HALT) is generally used for predicting the life time of rubber materials for a long period. Polyacrylate (ACM) with chlorine cure sites has been generally used for engine head gaskets. In order to improve the life time of such gaskets, ACM with carboxyl cure sites has been developed recently. In this study, we applied a mathematical model to obtain the recovery function of a rubber gasket, and utilized the fortran program in order to obtain the optimized recovery function by using the successive zooming genetic algorithm (SZGA). Comparisons of the mean squared error (MSE) between the function data and the experimental data have been made. The life times of ACM with carboxyl cure sites rubber gaskets for different compression rates were obtained using the Arrhenius model. More accurate quantitative predictions considering the maximum compression rate would be realized.]]></description>
      <pubDate>Tue, 28 Jun 2016 16:22:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1409456</guid>
    </item>
    <item>
      <title>Coupled Effect of Loading and Environment of Concrete Bridge in Service Life</title>
      <link>https://trid.trb.org/View/1336145</link>
      <description><![CDATA[A numerical method is proposed to study load and the environment couple effect during the service of a concrete bridge. By studying the corrosion process of reinforcement bars, the strain of the bars is decomposed into two parts, elastic strain and corrosion strain, and their ratio is defined as the corrosion factor. The time-dependent constitution of corrosion of the steel bar is obtained by introducing a nominal elastic module. According to the virtual work principle, the finite element formulation of the reinforcement concrete element is derived, and the computation sequence determined using the time history method is illustrated. The nonlinear finite element program is realized by the Fortran program to numerically solve the problem, which is verified by testing a model of three reinforced concrete beams. The results show that both stiffness matrix and the additional nodal load of the reinforcement concrete element should be considered in the couple effect analysis. The proposed method can be used to predict long-term mechanical properties of concrete bridges.]]></description>
      <pubDate>Wed, 14 Jan 2015 15:14:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1336145</guid>
    </item>
    <item>
      <title>Polyfit Program Users' Guide: A Statistical Polynomial Curvefitting Program: Version 2.0, Professional Fortran 77</title>
      <link>https://trid.trb.org/View/1264121</link>
      <description><![CDATA[POLYFIT is a user friendly program written in Microsoft Fortran for the IBM PC/AT and compatibles to perform polynomial regression analysis. This program allows the user to create and modify XY files (that is sample data containing from 5 to 50 XY pairs, X is the independent variable, Y is the dependent variable), or use an existing XY file as data input to the program. Menus are displayed to simplify program use. The program was designed to do polynomial curve fits for the given data set for orders 1, 2, and 3. A summary and plot of the fit for a selected order (1,2, or 3) is provided, as well as the option of hardcopy (printer output) if desired. Confidence intervals are computed and displayed as part of the summary of the chosen order of curve fit for the given sample data. A flow diagram of the program is included in Appendix A.]]></description>
      <pubDate>Mon, 28 Oct 2013 09:47:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1264121</guid>
    </item>
    <item>
      <title>Fortran IV Programs to Develop Contour Maps of 3-Dimensional Data : Progress Report</title>
      <link>https://trid.trb.org/View/1219124</link>
      <description><![CDATA[This report describes a series of FORTRAN-IV subroutines used to prepare graphical displays of three-dimensional data using either the printer or the CALCOMP plotter.]]></description>
      <pubDate>Tue, 27 Nov 2012 09:43:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1219124</guid>
    </item>
    <item>
      <title>Applications Manual for Logit Modes of Express Bus-Fringe Parking Choices</title>
      <link>https://trid.trb.org/View/1105692</link>
      <description><![CDATA[Manual computations and computerized applications of logit. models are described. The models demonstrated reflect travel behavior concerning express bus-fringe parking transit. The specific travel issues addressed include the basic automobile vs. express bus transit choice, model, transferability, between two study areas, submodal split, and n-dimensional choice modeling. A series of curves derived from th:e mathematical models are presented in the appendices to simplify computations. A FORTRAN subroutine for using these models within the Urban Transportation Planning System (UTPS) battery of computer programs for transportation planning is provided.]]></description>
      <pubDate>Wed, 20 Jul 2011 07:24:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1105692</guid>
    </item>
    <item>
      <title>CALCUL DES CONTRAINTES DANS UN MASSIF D'EPAISSEUR LIMITEE SOUMIS A UNE CHARGE TRAPEZOIDALE.</title>
      <link>https://trid.trb.org/View/1078299</link>
      <description><![CDATA[LE PROBLEME EST TRAITE PAR LA  METHODE DES SERIES DE FOURIER. LE CALCUL EST EFFECTUE SOUS LES HYPOTHESES SUIVANTES : - LA CHARGE TRAPEZOIDALE S'EXERCE SANS CISAILLEMENT SUR LA COUCHE DE FONDATION ; - LE SOL DE FONDATION EST FORME D'UNE OU PLUSIEURS COUCHES ELASTIQUES ET ISOTROPES ; - LE SUBSTRATUM EST A UNE PROFONDEUR FINIE ET EST RUGUEUX ; - LE PROBLEME EST BIDIMENSIONNEL. APRES UN RAPPEL DES DIFFERENTES METHODES UTILISEES POUR LE CALCUL DES CONTRAINTES DANS UN MASSIF ELASTIQUE, LE PROBLEME EST TRAITE MATHEMATIQUEMENT ; CETTE ETUDE DEBOUCHE SUR LA MISE AU POINT D'UN PROGRAMME DE CALCUL SUR ORDINATEUR (BIRUG), DONT ON EXPLIQUE L'UTILISATION PRATIQUE. ENFIN,  SONT ETUDIES LES DIFFERENTS PARAMETRES AYANT UNE INFLUENCE SUR LA REPARTITION DES CONTRAINTES : LA PROFONDEUR DU SUBSTRATUM, LE COEFFICIENT DE POISSON DE LA COUCHE COMPRESSIBLE, LA GEOMETRIE DU REMBLAI. UNE SERIE D'ABAQUES EST PRESENTEE EN ANNEXE ; ELLE MONTRE L'INFLUENCE DE CES DIFFERENTS PARAMETRES.(A)]]></description>
      <pubDate>Sun, 21 Nov 2010 16:49:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1078299</guid>
    </item>
  </channel>
</rss>