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    <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" />
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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>
    <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>Understanding Moving/Damage Mechanism of Vehicles under Tornadoes for Enhancing Vehicle/Driver Safety
</title>
      <link>https://trid.trb.org/View/2627651</link>
      <description><![CDATA[Tornadoes have caused catastrophic damage to buildings and vehicles. Although considerable research has been conducted on the performance of buildings under tornadoes, the performance of motor vehicles (e.g., cars, pickups, vans, and box trucks) under tornadoes was rarely studied. Unfortunately, about 15% of tornado fatalities during 1975–1995 were attributed to the moving or damage of motor vehicles and about 9% during 1985-2015. To protect motor vehicles from being damaged by tornadoes and accordingly to reduce tornado fatalities, the objective of this project is to understand the moving/damage mechanism of motor vehicles (e.g., sliding, flipping and lofting) under tornadoes using systematic computational fluid dynamics (CFD) simulations, which will be verified and validated by the PI’s large-scale laboratory tornado simulator. To achieve the stated research objective, three research tasks have been planned. The proposed research will answer the following five research questions. 1) What tornado intensity can cause a vehicle to slide, flip and loft, respectively? 2) What role does atmospheric pressure drop at tornado center play in initiating each vehicle motion? 3) What role does turbulence in tornadic wind field play in initiating each vehicle motion? 4) Does internal pressure inside a motor vehicle play any role in vehicle moving? and 5) What potential modifications can be made to motor vehicles in order to defer the initiating of each vehicle motion? The research findings can not only help regular vehicles in the parking lot or on the road experience less damage, but also can be integrated into autonomous vehicles for them to make informed decisions and then take proper actions to reduce the tornado-induced damage. In addition, research findings can be used to improve tornado safety recommendations for drivers on the road.
]]></description>
      <pubDate>Fri, 21 Nov 2025 14:07:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2627651</guid>
    </item>
    <item>
      <title>Investigating the Response Characteristics of Elevated Bridge Piles during Twin Stacked Shield Tunnel Excavations</title>
      <link>https://trid.trb.org/View/2603895</link>
      <description><![CDATA[To investigate the cumulative impacts of excavating twin stacked shield tunnels on the internal forces and deformations at forward target points and the effects of twin tunneling, this study employs a two-stage theoretical analysis method rooted in practical engineering and integrates numerical simulations to examine the response characteristics of nearby bridge piles to internal forces and deformations resulting from the excavation of stacked shield tunnels. First, by leveraging the Mindlin solution and accounting for dynamic spatiotemporal cumulative effects, analytical solutions for the three-dimensional displacement field and stress field of the surrounding rock during shield tunneling are derived and validated. Second, by employing the Pasternak foundation beam theory, theoretical solutions for the internal forces and deformations of nearby bridge piles associated with shield tunnels are presented. Last, considering the twin tunneling effects of excavating stacked tunnels, a maximum deflection correction parameter, η, is proposed for nearby bridge piles of twin stacked shield tunnel excavation to effectively rectify errors arising from a simple superposition of theoretical solutions. The findings provide a certain theoretical foundation and data support for the safety risk assessment of nearby bridge pile engineering during the excavation of twin stacked tunnels.]]></description>
      <pubDate>Thu, 13 Nov 2025 09:28:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2603895</guid>
    </item>
    <item>
      <title>Estimation of wave-induced full-field internal forces in submerged floating tunnels using LSTM network with finite impulse response filter and modal approach</title>
      <link>https://trid.trb.org/View/2554718</link>
      <description><![CDATA[Submerged floating tunnels (SFTs) are an innovative solution for underwater transportation. Although they offer significant advantages for deep-water construction, the practical implementation of SFTs remains challenging. This study addresses the need for the accurate estimation of wave-induced internal forces in SFTs using acceleration under varying wave conditions. Building on previous studies that employed long short-term memory (LSTM) networks, the authors propose an enhanced method that integrates an LSTM-based network with a finite impulse response (FIR) filter and a modal approach. The FIR filter is used to reconstruct the displacement from acceleration data, providing a stronger correlation with internal forces. The LSTM-based network then estimates the full-field strain and internal forces (tether tension, vertical bending moment, and lateral bending moment) by incorporating the modal information. The proposed method was validated using simulated data under diverse wave conditions, demonstrating improved accuracy and generalizability compared with the conventional LSTM model.]]></description>
      <pubDate>Thu, 05 Jun 2025 13:30:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2554718</guid>
    </item>
    <item>
      <title>Deep learning-based bridge damage identification approach inspired by internal force redistribution effects</title>
      <link>https://trid.trb.org/View/2343353</link>
      <description><![CDATA[Damage identification has always been one of the core functions of bridge structural health monitoring (SHM) systems. Damage identification techniques based on deep learning (DL) approaches have shown great promise recently. However, DL methods still need to be improved owing to their poor interpretability and generalization performance. The fundamental reason lies in the separation between physics-based mechanical principles and data-driven DL methods. To address this issue, this paper proposes a physics-inspired approach combining the data-driven method and the internal force redistribution effects to perform efficient damage identification. Firstly, the mechanical derivation of internal force redistribution is given based on a simplified three-span continuous bridge. Then, two types of typical damage scenarios including segment stiffness decrease and prestress loss are simulated to formulate the damage dataset with monitored field data noise added. Next, a modified Transformer model with multi-dimensional output is trained to obtain the complex dynamic spatiotemporal mapping among multiple measurement points from the intact structure as a benchmark model. Finally, the relationship between multiple damage patterns and the corresponding output regression residual distribution is studied, based on which the flexible combinations of the sensors are proposed as the test set to characterize the internal force redistribution due to damage. Validation on the extended dataset showed that this approach is effective to realize preliminary identification of damage patterns and resist interference from noise at the monitoring site.]]></description>
      <pubDate>Fri, 19 Apr 2024 09:38:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2343353</guid>
    </item>
    <item>
      <title>Structural response of submerged floating tunnels with free-end boundary condition based on an analytical approach</title>
      <link>https://trid.trb.org/View/2322939</link>
      <description><![CDATA[Until now, the investigation of structural behavioral characteristics of submerged floating tunnels (SFTs) has primarily relied on numerical methods that demand intensive calculations. This preference stems from the challenges in deriving an analytical solution, given the complexity of the structural system and applied loadings. To address this, an analytical approach based on practical assumptions has been developed to assess the structural responses of SFTs. Mainly, to mitigate excessive internal forces in tunnel segments and facilitate an analytical approach, a free-end boundary condition is assumed. Under these assumptions, the analytical approach can effectively determine the structural response of SFTs in the time domain. The proposed approach was validated by a hydrodynamics-based numerical analysis using the finite element method program ABAQUS/AQUA. In the harsh wave conditions of the Messina Strait, this approach matches well with numerical analyses, except in cases of extremely low submergence depth or exceptionally large tunnel diameter compared to mooring stiffness. This analytical approach can rapidly and accurately evaluate the structural behavior of SFTs, especially when considering the specific environment and design loads at the basic design stage. Therefore, this method is practically valuable. However, its application should be carefully exercised due to the several limitations.]]></description>
      <pubDate>Tue, 30 Jan 2024 09:25:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2322939</guid>
    </item>
    <item>
      <title>Pipe-soil interaction behaviors of deepwater J-lay pipeline on sloping seabed</title>
      <link>https://trid.trb.org/View/2294338</link>
      <description><![CDATA[The pipe-soil interaction behaviors are crucial factors for the J-lay pipeline design, which are mainly investigated on the horizontal seabed in previous studies. This paper develops an innovative method for the static and dynamic analyses of pipe-soil interactions considering the J-lay pipeline on a sloping seabed. This approach simulates the motion processes of the pipeline particles and solves the internal forces of the pipeline elements by the vector mechanics and finite element principle. The position coordinates formulations of pipeline particles are derived to calculate the pipeline locations on the sloping seabed. The non-linear hysteretic soil model and the modified Coulomb friction model are employed to simulate pipe-soil interactions in the vertical seabed plane as well as the axial and lateral directions. Moreover, a large-scale pipe-laying experimental test system is established to carry out the model experiments of a J-lay pipeline on different seabed conditions. The static and dynamic pipe-soil interaction responses are then analyzed by the VFIFE method for a 6-inch gas pipeline J-laying on the negative sloping seabed. The influence of seabed slope type and angle and soil characteristics is further explored on the pipe-soil interaction behaviors, which provide significant evidence for the design of pipe-lay on the sloping seabed.]]></description>
      <pubDate>Fri, 22 Dec 2023 08:46:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2294338</guid>
    </item>
    <item>
      <title>Change of Internal Force State in Element for Metal V-belt Type CVT Due to Increase of Transmitting Torque</title>
      <link>https://trid.trb.org/View/1982964</link>
      <description><![CDATA[The objective of this study is to reveal the change of internal force state in element for metal V belt type CVT under driving conditions, where the transmitting torque is changed. Changes of the internal force in width direction accompanying with the change of the moving location was measured by attaching small size strain gages on an element. The force in the element was remarkably fluctuated in the pulley groove. The representative point of the resultant force was moved toward the exit of pulley groove when the transmission torque was increased. Test result showing the difference in internal forces at the left position and that at the right position was also explained by the precessional motion of the movable sheave where the contacting point between belt and pulley was shifted in the radial direction under high torque condition.]]></description>
      <pubDate>Sun, 31 Jul 2022 15:21:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1982964</guid>
    </item>
    <item>
      <title>Internal Force Analysis of a Variable Displacement Vane Pump</title>
      <link>https://trid.trb.org/View/1825611</link>
      <description><![CDATA[The internal force of a variable displacement vane pump has been studied in detail with ten Computational Fluid Dynamics (CFD) cases with different pump speed and eccentricity. The internal moment increases considerably with faster pump speed, and at higher speeds, it can exceed the moment due to the spring force causing the slide to regulate at much lower pump discharge pressure. At low pump speeds, the effect of eccentricity is minimal. The maximum value of internal moment is expected to occur at high speeds and maximum eccentricity. There are two reasons for variation of internal moment with pump speed and eccentricity: (a) the variation of effective pressurized area of the slide changes with pump speed and (b) higher pressure in the blind ports at higher eccentricity. This study provides insight into pump forces during high-speed operation of vane pumps.]]></description>
      <pubDate>Mon, 13 Jun 2022 13:11:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1825611</guid>
    </item>
    <item>
      <title>Fatigue Crack Propagation of Welded Steel Pipeline under Cyclic Internal Pressure by Bézier Extraction Based XIGA</title>
      <link>https://trid.trb.org/View/1902929</link>
      <description><![CDATA[Residual stress and cracks after welding are widespread mechanical defects in gas and oil pipelines. Internal pressures cause crack propagation and reduce the fatigue life of pipelines. This study developed a new procedure, based on an extended isogeometric analysis (XIGA) to investigate the effect of welding residual stress and cyclic internal pressure on the crack propagation rate and fatigue life. A new approach based on a thermo elastic-plastic equation is introduced for residual stress analysis. The fundamental aspect of this approach is determining the redistribution of residual stress while the crack is growing, and computing the stress intensity factor (SIF) in the residual stress field. Grid points around the crack surface and crack front are identified by the level set method. Then, discontinuous enrichment functions are added to the XIGA approximation. Thus, remeshing is not required in this method. The residual stress results calculated by the presented numerical method are in good agreement with the hole-drilling strain-gage method results. The interaction integral method was used to extract SIF. The superposition method was employed to consider the effect of welding residual stress and cyclic internal pressure on the SIF. Also, the modified Walker equation was used to calculate the fatigue life caused by cyclic internal pressure and welding residual stress. To validate the results, the same analysis was performed using the finite element method. The results of the presented method are in good agreement with finite element method (FEM) results.]]></description>
      <pubDate>Fri, 28 Jan 2022 09:13:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1902929</guid>
    </item>
    <item>
      <title>Suspension bridge deformation and internal forces under the concentrated live load: Analytical algorithm</title>
      <link>https://trid.trb.org/View/1882193</link>
      <description><![CDATA[Suspension bridge is a flexible structure, which responses to live loads are quite complicated due to the coupling of several factors. In this paper, an analytical algorithm is proposed for estimating the deformation and internal forces of earth-anchored suspension bridges under the concentrated live load. Based on the known parameters of the completed bridge and the live load, the deformation of the main cable, the deformation of the girder, the relationship between the main cable and the girder, and the deformation of towers are successively analyzed. Next, four categories of governing equations are set up, namely, the conservation of the unstrained length of each main cable segment, the force and deformation coordination of each hanger, the closure of length and elevation difference in each span, and the mechanical balance of the girder. The total number of governing equations is equal to that of basic unknown parameters. Finally, all the governing equations are incorporated into an objective function, and the programming solution is carried out. The values of the basic unknown parameters are determined so that all the governing equations hold true simultaneously. Based on this, all other parameters are derived and the deformed state of the structure is expressed. The proposed method's feasibility and effectiveness are verified by its application to an earth-anchored suspension bridge with a main span of 1080 m. Both the deformation and internal forces under the live load are accurately estimated using the proposed analytical algorithm, which agree well with the finite element analysis.]]></description>
      <pubDate>Sun, 31 Oct 2021 19:08:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1882193</guid>
    </item>
    <item>
      <title>Improved Analytical Model and Algorithm for Computing Expansive Soil–Induced Stresses in Pavements</title>
      <link>https://trid.trb.org/View/1882836</link>
      <description><![CDATA[Estimating pavement internal forces due to the swelling or shrinking of expansive soils is of vital importance for planning, design, and construction. Such efforts can minimize some possible damage due to expansive soils during pavement services. This study extends an analytical model on the single-layer Euler–Bernoulli beam resting on the Winkler foundation to estimate pavement internal forces in the multilayer pavement structure. Besides, an improved efficient algorithm is proposed in this paper for computing the value of virtual load parameters. The proposed closed-form solution and iterative algorithm are then verified by comparing the degraded solution with the single-layer beam model and the existing iterative algorithm. The influences of the beam model (single layer or multilayer) and foundation parameters on the pavement internal forces have also been investigated through parametric studies. Furthermore, the computational efficiency is compared between the iterative algorithm adopted by the previous researcher and the iterative algorithm proposed in this paper. It can be seen that a single-layer beam model may underestimate pavement internal forces induced by expansive soils. Foundation parameters will affect the value of virtual load parameters. Also, it can be found that the iterative algorithm proposed in this paper can reduce the iterative calculation time considerably. Moreover, it can be observed that with more fitting points and fitting terms, the fitting has a more accurate effect, and the advantages of using the iterative algorithm proposed in this paper are more pronounced.]]></description>
      <pubDate>Fri, 29 Oct 2021 15:40:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1882836</guid>
    </item>
    <item>
      <title>A variable order framework for 3D nonlinear analysis of reinforced concrete frames under general loading</title>
      <link>https://trid.trb.org/View/1857417</link>
      <description><![CDATA[A framework for the analysis of three-dimensional reinforced concrete frame structures, capable of reproducing general failure modes, is presented. A force-based model which guarantees the equilibrium between nodal and sectional forces is enhanced by means of a cross-sectional model. It is capable of capturing the complex coupling between all the internal forces. Consequently, different failure modes can be reproduced such as shear, torsional, flexural or axial failures. Material modeling of concrete is made using a plastic-damage model that incorporates a variable dilatancy parameter. The sectional and constitutive models are implemented in OpenSees. The sectional model can be used at each integration point of the force-based element. Alternatively, it can be used only where high coupling between the internal forces is expected, producing a variable order structural model. The validation shows that the frame element is capable of accurately reproduce beams and columns under monotonic and cyclic loads. The framework presented is a powerful numerical instrument for the analysis, design and assessment of reinforced concrete buildings and bridges.]]></description>
      <pubDate>Fri, 23 Jul 2021 15:23:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1857417</guid>
    </item>
    <item>
      <title>Research on Aggregate Contact and Internal Force of Asphalt Mixture Based on Discrete Element Method</title>
      <link>https://trid.trb.org/View/1728374</link>
      <description><![CDATA[The contact state between the aggregates has a great influence on the overall performance of the asphalt mixture. This paper simulates different contact states in asphalt mixture based on discrete element method. Making mechanical analysis of the simulation model to explore the effect of contact state on the overall strength of asphalt mixture. It is concluded that line-to-surface contact and surface-to-surface contact account for the largest proportion of asphalt mixture and the greatest impact on asphalt mixture. When the center of mass of the two aggregates is on the same axis, the mix modulus is the largest and the structure is the most stable. The distribution pattern of aggregates also has a great influence on the strength of the mixture. The combination of structures with large contact and large degree of intrusion will significantly increase the strength of the structure.]]></description>
      <pubDate>Fri, 28 Aug 2020 17:31:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1728374</guid>
    </item>
    <item>
      <title>Performance Assessment of Shield Tunnel Damaged by Shield Shell Extrusion During Construction</title>
      <link>https://trid.trb.org/View/1629378</link>
      <description><![CDATA[A shield tunnel can be damaged by shield shell extrusions, such as shield tunnel floating, which may cause contact (even a squeezing action) between the shield tunnel and shield shell. To fully analyze this problem, a detailed 3D-finite element model (FEM) of a shield tunnel under the effect of a squeezing action in the shield tail, soil pressure, jacking force, and grouting pressure, was established by applying a plastic-damage constitutive model of concrete. A full-scale test of three segment rings was conducted, and the test results verified the feasibility of the constructed FEM. In this study, different squeezing positions and deflection angles of the shield shell were analyzed. The results indicated that the area squeezed by the shield shell experienced the most damage, and the tensile damage to a segment reduced gradually as the squeezing position approached the circumferential seam. The damage range gradually increased with the increase in deflection angle. The effect of the squeezing position of the shield shell on the bending moment was larger than the effect of the deflection angle on the bending moment. However, the effect of the squeezing position and that of the deflection angle on the shear force were the same.]]></description>
      <pubDate>Fri, 16 Aug 2019 15:51:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1629378</guid>
    </item>
    <item>
      <title>A method for calculus of Internal Forces</title>
      <link>https://trid.trb.org/View/1503207</link>
      <description><![CDATA[A new method to compute internal forces in a multi-bodies system is presented in the paper. Lagrange equations are used to study the motion of a system under the action of known external forces. If an internal force has to be found, a supplementary mobility is considered in the system and the corresponding internal force for the new mobility is found for null value of the mobility, as well as its first and second orders of derivatives. The method is a general one, but a particular case of mechanism used in the dynamics of the airplane elevator is analyzed to verify the validity of the proposed method.]]></description>
      <pubDate>Mon, 02 Apr 2018 10:23:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1503207</guid>
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