<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>Influence of wood core on the mechanical performance of sandwich composite submersible pressure hulls</title>
      <link>https://trid.trb.org/View/2673111</link>
      <description><![CDATA[This investigation aimed to determine the feasibility of fabricating a pressure hull using wood-sandwich composites to achieve significant weight reduction compared to steel. Five wood types, bamboo, paulownia, balsa, mulberry, and engineered mulberry, were analyzed. A parametric study was conducted to minimize weight and enhance stability under hydrostatic loading. The design of the sandwiched composite pressure hull depends on laminate layers, fiber angles, material system, thickness of the face sheets and core. This task presents a parametric design analysis to find out the optimized design for a pressure hull submerged under hydrostatic pressure by means of Finite Element Analysis (FEA). Material failure criteria were used to examine the failure of composite face sheets. Overall stability was examined using the buckling factor and maximum stress (MS) failure criterion. Various composite materials face sheets were employed, and numerous kinds of woods were implemented as a core with angle configuration of [0ₘ/90ₙ] and [45ₘ/-45ₙ]. The angle configuration of [45₁₄/-45₁₄]₂₈ with Paulownia core and CFRP face sheet, shows the minimum weight of 11,338 kg, which is less than around 20,000 kg of conventional steel pressure hull. The values of FStw, FSth, and λ were recorded 3.20, 2.43, and 1.44 respectively, with a von Mises stress of 160.75 MPa. The thickness of each face sheet and core was obtained 56 mm and 140 mm respectively. Achieving a 40–45% weight reduction compared to a steel hull, while fully satisfying all safety requirements, thereby confirming the feasibility of using wood-core composites for deep-sea pressure hull applications.]]></description>
      <pubDate>Fri, 29 May 2026 14:09:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2673111</guid>
    </item>
    <item>
      <title>Experimental and numerical analysis of critical buckling strength for a corrugated sheet under hydrostatic pressure</title>
      <link>https://trid.trb.org/View/2655834</link>
      <description><![CDATA[Membrane-type corrugated sheets have been used as the primary barriers for LNG carriers to reduce thermal and mechanical stress level. A small failure in primary barrier could cause severe leakage consequences. As the ship capacity increases, the action loads on the primary barrier also rise, making the corrugated sheets more prone to structural failure. This paper focuses on the buckling strength of a corrugated sheet under hydrostatic pressure. In this research, a series of symmetric and asymmetric hydrostatic pressure tests were carried out on a new type of corrugated sheets. Displacement, strain, and hydrostatic pressure were measured to provide comprehensive data on the weak parts of the corrugated sheet. Three-dimensional scanning revealed the deformation mode of the specimens after the test. FEM simulations were conducted to analyze the Mises stress distribution on the midspan section. Six different buckling criteria are defined, differing in physical quantity and buckling point selection. Their advantages, disadvantages, and applicability are discussed, providing the estimation of critical buckling strength from conservative to radical.]]></description>
      <pubDate>Thu, 09 Apr 2026 10:08:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2655834</guid>
    </item>
    <item>
      <title>The catastrophic failure of thick composite cylindrical pressure hulls: Analytical, numerical and experimental investigations</title>
      <link>https://trid.trb.org/View/2640985</link>
      <description><![CDATA[The catastrophic failure of thick composite cylindrical pressure hulls under high external hydrostatic pressure was investigated by analytical, numerical and experimental methods. Buckling failure and material failure were both considered to identify which failure mode of such thick hulls initiates first. An elastic buckling analytical model for thick composite cylinders based on Sander theory principles was applied to derive the critical buckling load. Meanwhile, a progressive damage model (PDM) was developed to simulate the material behavior in the region between the first-ply failure and ultimate failure, and the effects of failure criteria and geometrical defects on the implosion load of the test model were investigated. Then ultimate strength were obtained by comprehensive analysis of buckling failure and material failure via analytical and numerical methods. A group of two thick T700 carbon fiber/epoxy composite cylindrical pressure hulls were designed and manufactured, hydrostatic pressure tests were conducted to derive the catastrophic failure characteristics of thick composite pressure hulls and to validate the analytical and numerical results and methodology for the failure analysis of thick composite cylindrical pressure hulls.]]></description>
      <pubDate>Fri, 09 Jan 2026 16:59:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2640985</guid>
    </item>
    <item>
      <title>Theoretical analysis of elastic collapse in metallurgical clad pipes under external pressure</title>
      <link>https://trid.trb.org/View/2567280</link>
      <description><![CDATA[Metallurgical Clad Pipes (MCPs), due to their unique manufacturing process and excellent corrosion resistance, are key equipment for transporting highly corrosive oil and gas in offshore systems. However, the high external hydrostatic pressure in deep-sea environments poses significant risks of collapse, threatening the structural safety of MCPs. In this research, the elastic collapse performance of MCPs under external pressure is investigated by deriving a novel analytical formula based on Donnell shell theory and the Ritz method. The proposed formula considers the perpendicularity of pressure during deformation and is validated through comparisons with the DNV-ST-F101 formula and FEM simulations. The findings demonstrate that the elastic post buckling equilibrium path of MCPs follows the same pattern as that of conventional single-metal pipelines. Moreover, the proposed formula shows improved accuracy and greater applicability to various geometric properties and materials. Research works may provide a theoretical basis to improve the design and safety of MCPs and contribute to the ongoing development of offshore pipeline engineering.]]></description>
      <pubDate>Wed, 27 Aug 2025 10:26:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2567280</guid>
    </item>
    <item>
      <title>Computational analysis of submerged submarine bow hull dynamics subjected to torpedo blunt impact and warhead detonation events</title>
      <link>https://trid.trb.org/View/2577614</link>
      <description><![CDATA[In the maritime sector, ensuring the survivability of ships and submarines against diverse threats such as torpedo impacts, Underwater Explosion (UNDEX) events, and environmental factors is paramount. Comprehensive analysis of hull dynamics under various impact scenarios is essential. Numerical simulations of these impacts utilize different material models, ship grounding tests, impact modes, UNDEX simulations, and failure mechanisms. In the current study, the blunt impact of a torpedo on the submarine bow and the surface detonation effects of the torpedo warhead (at different distances from the hull) on the submarine bow structure were analyzed within an underwater enclosure. The torpedo design was based on the MK-48, with Ti6Al4V alloy used for the torpedo hull and HY-80 steel for the submarine hull. The impact simulations were conducted using ANSYS Explicit Dynamics® computational software. For the blunt impact scenario, a torpedo speed of 55 knots (102 km/h) was used. For the UNDEX studies, the warhead at the front end of the torpedo was modeled using PBX-9501 (a commonly used high explosive in warheads). The novelty of the current work was the employment of a water enclosure in the model to simulate the underwater impacts. The analysis focused on hull deformation, equivalent plastic and elastic strains, equivalent stress and damage profiles for the different impact scenarios. To effectively capture fluid–structure interactions, the study also examined pressure variations within the Eulerian domain. Among the scenarios analyzed, the near-field detonation of the warhead emerged as the most destructive, resulting in severe structural damage to the bow hull. In contrast, the blunt impact of the torpedo induced moderate plastic deformation, while the far-field detonation resulted in minimal damage.]]></description>
      <pubDate>Thu, 14 Aug 2025 17:10:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2577614</guid>
    </item>
    <item>
      <title>Methodology for simulating ship damage stability and liquid cargo outflow for collision-damaged ships</title>
      <link>https://trid.trb.org/View/2583980</link>
      <description><![CDATA[Ship collisions and groundings are important due to their severe consequences, including exceedance of ultimate strength, loss of stability, and spillage of hazardous cargo and liquids. To mitigate these effects, cost-efficient simulation tools are needed for studying transient flooding and motions of damaged ships with different damage opening characteristics in a wave environment. The objective of this study is to present a validation of a liquid exchange model implemented in the time-domain-based dynamic ship stability simulation code SIMCAP, using experiments presented in the literature. The validated model was then applied in a parametric study of a fully loaded double-hull oil tanker damaged in the inner and outer hulls. Oil outflow, water inflow, and ship motions were analysed for different damage opening positions, shapes, and wave heights. The results showed that the damage location strongly affected the oil outflow. The oil spill rate increased with wave height but was relatively unaffected by heading and wave realization. In conclusion, SIMCAP was reasonably validated qualitatively and quantitatively and is suitable for investigating key physical mechanisms in parametric studies of damaged ships in waves.]]></description>
      <pubDate>Wed, 13 Aug 2025 09:25:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2583980</guid>
    </item>
    <item>
      <title>The influence of hydrostatic pressure load on the loss of submarine buoyancy</title>
      <link>https://trid.trb.org/View/2528589</link>
      <description><![CDATA[This study analyses the impact of hydrostatic pressure on the loss of buoyancy of a submarine. The study focuses on a deeper understanding of submarines’ buoyancy principles, discussing the concept of residual buoyancy and presenting the relationships related to trimming submarines. This issue is crucial from the point of view of the safety and operational effectiveness of submarines. The research was carried out using the finite element method and laboratory tests of construction materials. A mathematical model of steel used for submarines is presented. The results obtained during the research will be used to improve underwater units’ design processes and better understand their operation procedures.]]></description>
      <pubDate>Thu, 08 May 2025 14:22:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528589</guid>
    </item>
    <item>
      <title>A comparative analysis of numerically simulated and experimentally measured static responses of a floating dock</title>
      <link>https://trid.trb.org/View/2512581</link>
      <description><![CDATA[Two numerical methods, dynamic and static analyses, are proposed to calculate the static responses of a floating dock under different ballast water distributions. Model-scale experimental tests were conducted to compare with these numerical methods. The dynamic analysis includes a 6-degree-of-freedom (6-DOF) model, a hydrostatic force model and a hydrodynamic force model to simulate the dock's freely floating processes. The dock's equilibrium position is identified when the difference in the dock’s motions between two successive time steps is below a specified tolerance value. In the static analysis, the static equilibrium equations in draught, heel, and trim are solved using the Newton-Raphson method. Both dynamic and static results of the draughts at the four corners, heel, and trim are in good agreement with the corresponding experimental results, which shows the reliability of the proposed numerical methods. Moreover, the static analysis exhibits quicker convergence, requiring fewer iteration steps than the dynamic analysis.]]></description>
      <pubDate>Tue, 25 Mar 2025 09:32:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2512581</guid>
    </item>
    <item>
      <title>Multi-fidelity strength monitoring method for dynamic response of deep-sea pipelines based on digital-twin technology</title>
      <link>https://trid.trb.org/View/2488310</link>
      <description><![CDATA[Cost-effective structural monitoring of deep-sea pipelines in harsh environments is essential for advancing deep-sea oil and gas development. This paper presents a multi-fidelity monitoring method for deep-sea pipelines based on digital twin (DT) model, applied to dynamic response monitoring under high pressure and forced vibration. This method integrates low-fidelity (LF) data from numerical simulations—clustered using the Hierarchical Geodesic K-means++ (HG-kmeans++) method—with high-fidelity (HF) data from full-scale pipeline tests. A pre-training model is developed using XGBoost based on LF data, and a DT model is established via the XGBoost-based Stacking-CGAN (XS-CGAN) method by integrating multi-fidelity data. A case study involving full-scale experiment demonstrates that the proposed approach significantly enhances both global and local accuracy. Compared to finite element analysis (FEA), the RRMSE and REmax improve by 40 % and 55.61 % respectively, outperforming current advanced method by 5.14 % and 3.79 %. These findings demonstrate the method's practical value for structural monitoring of deep-sea pipelines.]]></description>
      <pubDate>Tue, 28 Jan 2025 09:20:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2488310</guid>
    </item>
    <item>
      <title>Reliability analysis for ultimate strength evaluation methods of ring-stiffened cylindrical shells under hydrostatic pressure</title>
      <link>https://trid.trb.org/View/2488195</link>
      <description><![CDATA[This paper discusses the buckling characteristics and ultimate strength evaluation of ring-stiffened cylindrical shells under hydrostatic pressure. The predicted value and experimental value of ultimate strength are sourced from public literature and specifications. Based on experimental parameters, the ultimate strength is counted by the theoretical formulas of Rules for the classification of diving systems and submersibles (CCS. 2018. Rules for classification of diving systems and submersibles. Beijing) and Underwater vehicles, Systems and hyperbaric facilities (ABS. 2012. Rules for building and classing-Underwater vehicles, systems and hyperbaric facilities. The State of New York) is analysed and compared. ABAQUS is used to develop models and experimental value and predicted value with theoretical formulas are compared through the finite element software analysis. According to the deviation and coefficient of variation (COV), the reliability of different analysis results is analysed, and the reliability range of different parameters for theoretical formulas and finite element analysis are discussed.]]></description>
      <pubDate>Mon, 27 Jan 2025 08:49:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2488195</guid>
    </item>
    <item>
      <title>Damage prediction of hull structure under near-field underwater explosion based on machine learning</title>
      <link>https://trid.trb.org/View/2459286</link>
      <description><![CDATA[Underwater explosions generate diverse loads, encompassing shock waves and bubble pulsation, and pose a substantial threat to naval vessels. In this study, finite element simulations were carried out to evaluate the response of the hull to different underwater explosion cases, including varying TNT masses and standoff distances. With the increase of the standoff distance, the deformation of the bottom plate was observed to exhibit a multi-peak phenomenon with a sharp decrease followed by a slight increase and subsequent reduction. Based on a large hull damage dataset obtained from the finite element simulations, a deep neural network (DNN) model was trained using machine learning (ML) algorithms. The deformation values predicted by the model were found to closely match the simulation results. This method provides an approach for the rapid prediction of the deformation of hull structures under near-field underwater explosions.]]></description>
      <pubDate>Fri, 13 Dec 2024 17:02:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2459286</guid>
    </item>
    <item>
      <title>Numerical modelling of upheaval buckling of offshore pipelines with unstressed and stressed initial imperfections</title>
      <link>https://trid.trb.org/View/2424189</link>
      <description><![CDATA[Buried offshore pipelines transporting hydrocarbon at high temperatures and pressures might experience upheaval buckling. Although pipelines are designed to remain in place, field evidence shows that the buried pipeline might displace a significantly large distance in the upward direction. In the present study, the pre- and post-buckling behaviour of offshore pipelines buried in sand is investigated considering the degradation of uplift soil resistance with the upward displacement of the pipe. The soil resistance degradation models are implemented in a finite element program, and the analyses are performed for large upward displacements even when a buckled section moves above the seabed. The simulation results show that the capacity of the pipeline to carry the load generated from an increase in pressure and temperature reduces significantly if post-peak degradation of uplift soil resistance is considered. The effects of the internal pressure modelling approach, uplift soil resistance degradation model, burial depth and pipe dimensions (diameter and thickness) on upheaval buckling for varying initial imperfections are investigated. Based on a simplified model for developing initial stresses in a pipeline during installation, it has been shown that initial stresses primarily affect the upheaval buckling at lower ranges of upward displacement of the pipe.]]></description>
      <pubDate>Tue, 17 Sep 2024 09:25:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2424189</guid>
    </item>
    <item>
      <title>Data-driven semianalytical method for predicting equivalent thickness of flexible pipeline carcass</title>
      <link>https://trid.trb.org/View/2322935</link>
      <description><![CDATA[The carcass layer inside a flexible marine pipeline is a large-angle spiral structure with a complex cross-section. A carcass resists radial loads and prevents flexible pipelines from collapsing under extreme hydrostatic pressures. The accurate evaluation of the critical collapse pressure of a carcass under external pressure is crucial for the safe design of flexible pipelines. Because of the complex cross-section of the carcass, the internal surface of the carcass slides and contacts adjacent layers under external loads, which complicates the analysis. Therefore, the complex cross-section of the carcass is often simplified into a uniform section with a fixed thickness during analysis. In this study, parametric models of the carcass with different cross-sectional parameters were established, and the radial stiffness of the carcass under symmetric radial compression was calculated numerically. Next, the calculated equivalent radial stiffness was introduced into the analytical model to obtain geometric coefficients with different cross-sectional parameters. Finally, symbolic regression was used to derive a mathematical equation relating the equivalent thickness and critical cross-sectional parameters of the carcass. The results showed that the Minimum error in the buckling eigenvalue between the equivalent models and full carcass layer model was 6.2 %, the error in the critical collapse pressure was 14.5 %. Meanwhile, the influence of different parameters on the critical collapse pressure of the carcass was discussed.]]></description>
      <pubDate>Tue, 30 Jan 2024 09:25:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2322935</guid>
    </item>
    <item>
      <title>A new automatic measurement system for high-speed railway substructure settlement based on hydrostatic pressure difference levelling</title>
      <link>https://trid.trb.org/View/1898800</link>
      <description><![CDATA[Exact settlement measurement of substructures plays an important role in their status detection throughout all-life-cycle of high-speed railway. A Hydrostatic Pressure Difference Levelling system (HPDL) is developed based on the mechanism that pressures of any two points at different elevations in incompressible static liquid are different. The approach accounts for a hyperbolic variation in the density of the pressure transmission liquid with temperature, variation in the earth’s gravitational field and the elevation at the measurement point. High accuracy capacitive differential pressure transmitters are adopted owing to their high sensitivity, temperature-insensitive, low energy consumption, and sensing stability. The HPDL results are verified with settlement values measured by the precise level. It was demonstrated that the HPDL results correlate well with the precise level and can be considered as an effective method to measure the settlement of high-speed railway substructures.]]></description>
      <pubDate>Fri, 21 Jan 2022 11:43:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1898800</guid>
    </item>
    <item>
      <title>Experimental Investigation on the Influence of Ambient Temperature on the Test Accuracy for the Differential Pressure Hydrostatic Levelling System</title>
      <link>https://trid.trb.org/View/1895116</link>
      <description><![CDATA[Hydrostatic levelling system (HLS) is widely used to monitor the settlement of major projects, such as high-speed railways, bridges, tunnels, dams, and nuclear power plants; ambient temperature is the most important influencing factor in the actual engineering settlement detection process. In order to systematically study the influence of ambient temperature T [subscript A] on the test accuracy of the HLS, a test platform was built in the ambient temperature laboratory, and the influence of factors, including the amount of T [subscript A] change, the rate of increase/decrease of T [subscript A], the expansion coefficient of the connecting pipe, and the distance of the measuring point, on the HLS test accuracy was quantitatively analyzed. The test results show that the elevation of a single HSL case has a linear correlation with the ambient temperature; when the temperature rise rate is greater than 0.1°C/min, the measured data are distorted due to incomplete development of material expansion. The temperature influence coefficient of a single HSL case is linearly related to the expansion coefficient deviation between the refrigerant and pipe; the test error of the double HLS case caused by T [subscript A] is attributed to the expansion coefficient deviation of the pipe and the refrigerant between the  base station and the measuring point. The relative temperature influence coefficient increases as distance measurement increases, and the HLS test error caused by T [subscript A] will maintain a constant value when the distance measurement exceeds a certain value.]]></description>
      <pubDate>Tue, 21 Dec 2021 09:44:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1895116</guid>
    </item>
  </channel>
</rss>