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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
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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>Failure analysis of the floating pipeline with defect under flooding load</title>
      <link>https://trid.trb.org/View/1529988</link>
      <description><![CDATA[Crossing pipelines buried under the rivers will be easy to float in a flood. The impact of floods on the exposed pipes can cause significant bending deformation and even rupture. Furthermore, pipelines with defects are more prone to failure, resulting in serious environmental disasters. This paper is focused on the fracture failure of the floating pipe. A mechanical model of the free spanning pipeline in a flood including nonlinear interaction between the pipeline and soil was built. The distribution of stress and displacement of the floating pipeline was studied by nonlinear FE method. Dangerous sections of the floating pipeline were obtained. Pipelines contain defects because of corrosion and mechanical damage. The allowable critical dimension of the defect is proposed for the safety assessment of floating pipes with defects. Local finite element models of pipelines with defects were established under the combined effect of internal pressure, bending moments and axial force which can be obtained from the pipe-soil coupling mechanical model. Based on the method of plastic limit, Python was used to modify the dimensions of the volumetric defect to obtain the allowable critical dimension under the given condition by example of API X70  φ1016. This may provide more convenient reference for the safety assessment of pipelines with defects in practical engineering. The paper also analyzed the influence factors of pipeline stress and the critical dimension, such as the spanning length, crossing angle of pipeline, and the velocity of flood flow.]]></description>
      <pubDate>Mon, 13 Aug 2018 22:26:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1529988</guid>
    </item>
    <item>
      <title>Computation of mechanically coupled bodies in a seaway</title>
      <link>https://trid.trb.org/View/1499582</link>
      <description><![CDATA[The paper is concerned with the simulation of mechanically coupled bodies in seaway. While the applications of such cases are very wide, they are of particular interest for offshore operations, e.g. towing and boat landing. The focus of the present study is to supplement a viscous flow solver by appropriate mechanical models to analyse the hydrodynamics of coupled bodies due to mechanical joints. A quaternion-based motion modeller has been implemented using several basic joint elements to model their influence in a multi-body system. Examples included refer to rigid links, ropes, fenders or guide frames to restrict the motion in experiments, and aim to illustrate the predictive accuracy of the procedure and generic applications utilising all features of the computational framework including an overset grid technique.]]></description>
      <pubDate>Mon, 30 Apr 2018 17:21:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1499582</guid>
    </item>
    <item>
      <title>A mechanistic model of lateral rail head deflection based on fastening system parameters</title>
      <link>https://trid.trb.org/View/1485100</link>
      <description><![CDATA[This paper presents a mechanistic model of the rail head lateral deflection with the aim of quantifying the distribution of the lateral wheel load in a concrete sleeper rail track. The model is developed based on observations of the field experimentation and the results of a three-dimensional validated finite element model. The input parameters of the model are primarily based on the design of the fastening system and the track structure. In the developed model, the rail head lateral deflection is divided into two components which are computed separately: rail base lateral deflection and rail head rotational deflection. The model considers the possible gap between the field-side shoulder and insulator, and assumes Coulomb Law of friction for the rail base interfaces. Based on an experimental design approach, the prediction of the mechanistic model is compared with that of finite element model as well as with field data.]]></description>
      <pubDate>Mon, 23 Oct 2017 13:41:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1485100</guid>
    </item>
    <item>
      <title>Advanced Modelling for Rigid Pavement Assessment Using HWD</title>
      <link>https://trid.trb.org/View/1414228</link>
      <description><![CDATA[Armed with its experience of the flexible airfield pavement testing for which an advanced dynamical method was developed and a technical guidance released in 2014, the French Civil Aviation Technical Center (STAC) took on the challenge of transposing the methodology to rigid pavements. The approach is the same as for flexible pavement: first the development of a mechanical model allowing calculating stresses and strains in the concrete slab under Heavy Weight Deflectometer (HWD) impulse loading, which can be used in a backcalculation process, and then the implementation of damage prediction laws. The developed mechanical model is based on a 3D finite element (FE) technique. It enables considering either static or dynamical impulse HWD loading, applied on the concrete slab center, slab edge, or slab corner, for an isolated slab. A thermo-mechanical model is included in the FE model and enables computing the slab deformation as a function of the thermal gradient in the slab. The resulting deformation can be used as initial geometrical input, as well as related internal stresses, for the above mechanical calculation. The numerical results have been compared with experimental data from HWD tests performed on the STAC's full-scale instrumented test facility. The latter comprises a 700 m² rigid pavement including doweled and non-doweled areas. It is instrumented in the neighborhood of slab corners and middle of slab edges with sensors measuring vertical displacements on the loaded slab and the adjoining ones, and tensile strains at the bottom of the slab. An HWD survey was conducted on both doweled and non-doweled areas, including multi-height tests at different positions on the instrumented slabs. This paper first describes the dynamical 3D FE modeling developed, and the numerical results obtained. Then, the results of the full-scale validation are presented, which include comparison between expected surface deflections and HWD measurements, and comparison between predicted strain values and those recorded by embedded sensors.]]></description>
      <pubDate>Wed, 28 Sep 2016 15:46:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1414228</guid>
    </item>
    <item>
      <title>Sensitivity analysis for energy demand estimation of electric vehicles</title>
      <link>https://trid.trb.org/View/1409617</link>
      <description><![CDATA[The authors present a sensitivity analysis for a mechanical model, which is used to estimate the energy demand of battery electric vehicles. This model is frequently used in literature, but its parameters are often chosen incautiously, which can lead to inaccurate energy demand estimates. The authors provide a novel prioritization of parameters and quantify their impact on the accuracy of the energy demand estimation, to enable better decision making during the model parameter selection phase. The authors furthermore determine a subset of parameters, which has to be defined, in order to achieve a desired estimation accuracy. The analysis is based on recorded global positioning system (GPS) tracks of a battery electric vehicle under various driving conditions, but results are equally applicable for other battery electric vehicles (BEVs). Results show that the uncertainty of vehicle efficiency and rolling friction coefficient have the highest impact on accuracy. The uncertainty of power demand for heating and cooling the vehicle also strongly affects the estimation accuracy, but only at low speeds. The authors also analyze the energy shares related to each model component including acceleration, air drag, rolling and grade resistance and auxiliary energy demand. The authors' work shows that, while some components make up a large share of the overall energy demand, the uncertainty of parameters related to these components does not affect the accuracy of energy demand estimation significantly. This work thus provides guidance for implementing and calibrating an energy demand estimation based on a longitudinal dynamics model.]]></description>
      <pubDate>Tue, 28 Jun 2016 16:37:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1409617</guid>
    </item>
    <item>
      <title>Research on mechanical model for the J-lay method</title>
      <link>https://trid.trb.org/View/1363029</link>
      <description><![CDATA[The J-lay method is regarded as the most feasible way to lay pipeline in ultra-deep water; however, the time required to compute the forces generated is considerable. In this article, a new and simple mechanical model is developed in order to reduce the calculation time required. It comprises two parts: the first is a pipe–soil interaction model based on the linear beam theory and the Winkler foundation model, and the second is a nonlinear, large deflection beam theory to calculate the forces on the suspended segment. The accuracy of the numerical calculations has been verified against the output of commercial software with good results. Furthermore, high-order shear effect, which has been largely ignored in other publications, is discussed. The results show that computational accuracy can be improved by 3.1% by taking this effect into account. Therefore, the mechanical model proposed in this article is quicker and more accurate for determining the forces encountered during J-lay operations.]]></description>
      <pubDate>Fri, 28 Aug 2015 13:59:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1363029</guid>
    </item>
    <item>
      <title>Release of the French Technical Guidance for Flexible Airfield Pavement Assessment Using HWD</title>
      <link>https://trid.trb.org/View/1356748</link>
      <description><![CDATA[This paper presents the technical guidance released in 2014 by the STAC (Service Technique de l’Aviation Civile : French Civil Aviation Technical Center), relative to Flexible Airfield Pavement Assessment using Heavy Weight Deflectometer (HWD) which aims at providing all airport technical managers with a methodology for pavement testing using HWD. It gathers recommendations relative to operational survey and data analysis, based on an advanced dynamic modeling which overcomes the limitations encountered with the usual static analysis methods. The operational recommendations include all information about airport platform survey and the carrying out of the tests, whereas the recommendations relative to the data analysis gather the description of the mechanical modeling and its parameters, as well as the one of the associated backcalculation process developed. All parts of the guide have been validated, numerically or using in-situ measurements. The last part of the document is dedicated to illustrations through real case studies. This paper describes the content of this guide and particularly points out the new main developments compared with usual HWD test protocols and analysis methods.]]></description>
      <pubDate>Mon, 29 Jun 2015 15:52:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1356748</guid>
    </item>
    <item>
      <title>An Analytical Mechanical Model for Tunnel Segmental Joints Subjected to Elevated Temperatures</title>
      <link>https://trid.trb.org/View/1356517</link>
      <description><![CDATA[This paper presents an analytical mechanical model for tunnel boring machine (TBM) tunnel lining segmental joints exposed to fire. Based on the general flat joint model, the model was derived under the thermal effect induced by elevated temperature. A fitting function for describing the relationship among the ratio of concrete deformation, strain in the outer edge of compressive zone of joint and height of compressive zone is proposed using a result from a finite element method (FEM) analysis in which parameters were obtained by calibration against true scale model tests. The concept of temperature adjustment coefficient on joint section is proposed, which improves the calculation method of joint section temperature field. Influence of elevated temperature and axial force on the bending moment characteristic of a segmental joint was examined. The validation of this model was through the comparison with the results of fire tests. This model contributes to comprehending mechanics characteristics of shield TBM tunnel lining joint under high temperature and the design of the joint.]]></description>
      <pubDate>Mon, 29 Jun 2015 09:13:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1356517</guid>
    </item>
    <item>
      <title>Nanomechanical Evaluation of Vapor-Conditioned and Unconditioned Asphalt</title>
      <link>https://trid.trb.org/View/1339297</link>
      <description><![CDATA[Traditionally, moisture damage of asphalt concrete (AC) is evaluated by comparing the macroscale strength and stiffness values of a set of moisture- or vapor-conditioned samples with those of a set of unconditioned AC samples. The moisture damage of a bulk (liquid) asphalt binder is determined by the surface energy components of the binder with a Wilhelmy plate device: the most recent and advanced way to evaluate moisture damage in liquid asphalt. Despite these advancements, moisture damage in AC or asphalt binder is an unsolved issue. Different from previous approaches, this study evaluated the moisture damage of thin films of asphalt deposited on glass substrates, conditioned at 25%, 49%, and 71% vapors, and used a nanoindentation technique for testing. In nanoindentation, a point load indents the asphalt film surface and load–displacement data are recorded. The study analyzed nanoindentation data with the traditional Oliver–Pharr method and a nontraditional mechanical model that captures the viscoelastoplastic behavior of the indented film with spring, dashpot, and rigid (SDR) body elements. The model results showed that the modulus and hardness of asphalt film decreased with an increase in vapor level. The SDR model showed that at higher humidity, at 49% and 71% humidity conditions, the viscosity decreased by approximately 60% in thin film binder.]]></description>
      <pubDate>Wed, 11 Feb 2015 12:21:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1339297</guid>
    </item>
    <item>
      <title>Technical evaluation of a runway using the deflection method</title>
      <link>https://trid.trb.org/View/1286301</link>
      <description><![CDATA[An aircraft imposes a heavy load on a runway during landing, resulting in deflection of the runway pavement. Therefore, runway performance is influenced by potential deflection levels. Estimating deflection at touch-down point is a challenging task, however. Generally, the applied load depends on the weight and vertical velocity of the aircraft before hitting the touchdown point. Similarly, performance of runway pavement is influenced by many factors such as number of landings, load factor, soil characteristics, etc. This study discusses landing practices, imposed load analysis, and runway pavement evaluation. The study is based on the idealisation of runway characteristics using mechanical elements, and it suggests that the mechanical modelling approach can be applied to estimate runway deflection. As a result, the analytically predicted deflection findings instead of the semi-empirical practices currently followed by various states of the International Civil Aviation Organisation (hereinafter -- ICAO) can be used to carry out technical evaluation of a runway pavement.]]></description>
      <pubDate>Wed, 26 Mar 2014 10:11:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1286301</guid>
    </item>
    <item>
      <title>Dynamic Modulus Testing and Mechanical Modeling for New Mexico Asphalt Mixtures</title>
      <link>https://trid.trb.org/View/1275604</link>
      <description><![CDATA[This paper presents the laboratory testing and analysis performed to determine dynamic modulus (E*) and phase angle of two plant produced asphalt mixes of New Mexico. Dynamic modulus testing is conducted on three samples of plant produced SP-II and SP-III samples collected from a construction site in New Mexico. To develop mastercurve, dynamic modulus testing is performed at -10, 4, 21, 37 and 54°C with loading frequencies of 0.1, 0.5, 1.0, 5, 10 and 25Hz at each temperature. Data from each test is processed to determine the dynamic modulus and develop mastercurve. In addition, the Wiechert model is optimized to predict the storage modulus master curves for both mixes. Viscoelastic material inter-conversion techniques are also applied to estimate creep compliance and relaxation modulus mastercurves.]]></description>
      <pubDate>Wed, 04 Dec 2013 16:48:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1275604</guid>
    </item>
    <item>
      <title>Evaluation of methods for the development of representative responses and corridors from biomechanical data using mechanical models</title>
      <link>https://trid.trb.org/View/1278355</link>
      <description><![CDATA[The development of representative responses and corridors from biomechanical data is essential for the validation of computational models and anthropometric test devices. While various empirical and statistical methods have been proposed for generating representative responses and corridors from data, it is often unclear on what basis the generated representative responses and corridors typify the biomechanical behaviour or its range of variations. The quality of the representative responses and corridors generated by various techniques from the literature was evaluated by comparing two linear mass-spring-damper models with the responses of average (or median) models and simulations using random resampling. One of these models was validated to lower limb axial impact experiments in order to provide a realistic evaluation of actual biomechanical data. This lower limb model has parameters dependent on the anthropometry and bone mineral density of the specimens and was significantly better in predicting the responses of a target specimen than the mass-scaling method. While more intricate scaling methods are possible, this result implies that model-based approaches may be a better tool for predicting the responses of a target population than the traditional mass-scaling method. The evaluation results showed that the consistency of any method's representativeness relative to the ‘true’ corridor was dependent on the type of data collected in the original experiments. Since there were inconsistencies in the quality of the generated corridors with these two models, a model-based evaluation should be considered as an additional step in choosing a corridor development method for a particular problem.]]></description>
      <pubDate>Wed, 27 Nov 2013 10:21:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1278355</guid>
    </item>
    <item>
      <title>Social Force based Vehicle Model for Two-Dimensional Spaces</title>
      <link>https://trid.trb.org/View/1129193</link>
      <description><![CDATA[There is a growing interest in modeling heterogeneous traffic. This is especially true in Asian countries where a wide variety of transport modes operate on streets under differing traffic rules. There is also growing interest by urban planners and traffic engineers in applying the shared space or living street concepts to roadways. These approaches remove the traditional segregation of different road users by replacing lane markings and curbs with open spaces for use by all road users. There is some debate including safety and capacity issues when integrating pedestrian, bicyclists and car movement on an open space with little guidance. Current microscopic traffic flow models are not suitable when pedestrians, bicycles, cars and heavy vehicles share the same space since these modes have very different levels of maneuverability and speeds. Most current microscopic traffic flow models are 1- dimensional; they are based on car-following modes with limited consideration of lateral interaction. In contrast, social force models, frequently used to model pedestrian behavior, consider 2-dimensional motion and are not link-based. These models use an interacting force between pedestrians and obstacles to model walking and are often applied for crowd modeling. This paper presents an approach for extending the social force model to models also for vehicles movements. In contrast to traditional car-following models, the proposed approach uses a mechanically-based model to obtain reasonable turning trajectories and a proportional–integral–derivative (PID) controller is integrated to control the simulated vehicles. The method was tested using data collected by video imaging at a T-intersection that was recently converted to a shared space area. Results of this case study show that the trajectories simulated using the proposed model are good approximations of the real trajectories.]]></description>
      <pubDate>Fri, 25 May 2012 09:31:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1129193</guid>
    </item>
    <item>
      <title>Upscaling quasi-brittle strength of cement paste and mortar: A multi-scale engineering mechanics model</title>
      <link>https://trid.trb.org/View/1100381</link>
      <description><![CDATA[It is well known from experiments that the uniaxial compressive strength of cementitious materials depends linearly on the degree of hydration, once a critical hydration degree has been surpassed. It is less known about the microstructural material characteristics which drive this dependence, nor about the nature of the hydration degree-strength relationship before the aforementioned critical hydration degree is reached. In order to elucidate the latter issues, the authors here present a micromechanical explanation for the hydration degree-strength relationships of cement pastes and mortars covering a large range of compositions: Therefore, the authors envision, at a scale of fifteen to twenty microns, a hydrate foam (comprising spherical water and air phases, as well as needle-shaped hydrate phases oriented isotropically in all space directions), which, at a higher scale of several hundred microns, acts as a contiguous matrix in which cement grains are embedded as spherical clinker inclusions. Mortar is represented as a contiguous cement paste matrix with spherical sand grain inclusions. Failure of the most unfavorably stressed hydrate phase is associated with overall (quasi-brittle) failure of cement paste or mortar. After careful experimental validation, the study's modeling approach strongly suggests that it is the mixture- and hydration degree-dependent load transfer of overall, material sample-related, uniaxial compressive stress states down to deviatoric stress peaks within the hydrate phases triggering local failure, which determines the first nonlinear, and then linear dependence of quasi-brittle strength of cementitious materials on the degree of hydration.]]></description>
      <pubDate>Fri, 29 Apr 2011 07:36:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1100381</guid>
    </item>
    <item>
      <title>Modelling Linear Viscoelastic Properties of Asphalt Concrete by the Huet–Sayegh Model</title>
      <link>https://trid.trb.org/View/906915</link>
      <description><![CDATA[In order to seek an appropriate mechanical model to describe the complex modulus and characterise the linear viscoelastic property of asphalt concrete, the Huet–Sayegh model was studied in this research. Laboratory tests of complex modulus were conducted on 20 different mixtures. Several mechanical models (Maxwell, Kelvin, generalised Maxwell, generalised Kelvin and Huet–Sayegh) and the mathematical model of sigmoidal function were applied to establish master curves of dynamic moduli. Results indicate that the Huet–Sayegh model can describe complex modulus more accurately using fewer numbers of parameters compared with other mechanical models.]]></description>
      <pubDate>Mon, 25 Jan 2010 08:09:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/906915</guid>
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