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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>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Assessment method for the strength of typical hull structures under repeated ice impacts</title>
      <link>https://trid.trb.org/View/2641293</link>
      <description><![CDATA[Polar vessels experience repeated ice impacts, leading to the gradual accumulation of plastic deformation in the hull structure, which may result in structural failure and seriously compromise the safety of polar operations. This paper focuses on stiffened panels, a typical structural component in ship hulls, and conducts numerical simulations of repeated impacts using an ice indenter. In addition, repeated impact tests on stiffened panels under the action of a wedge-shaped ice indenter are carried out using a drop-weight impact test apparatus. The results show good agreement between numerical simulations and experimental data in terms of permanent deformation of the stiffened panel. The critical deformation corresponding to the pseudo-shakedown behavior of the stiffened panel is identified. When the central deformation of the panel remains below this critical value, the structure enters a pseudo-shakedown state, where energy absorption difference and central deformation stabilize at constant levels. However, once the deformation exceeds this threshold, the growth rate of deformation increases rapidly, likely leading to accelerated structural failure. By adopting the critical deformation at the pseudo-shakedown state as a characteristic indicator of structural failure, a mapping relationship between this deformation and structural damage is established. A strength assessment criterion based on the critical pseudo-shakedown deformation is proposed, leading to the development of an evaluation methodology for large deformation damage in polar ship structures under impact loads.]]></description>
      <pubDate>Wed, 11 Mar 2026 14:41:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/2641293</guid>
    </item>
    <item>
      <title>Prediction of resistance reduction for ice-going ships installed with air-bubbling systems</title>
      <link>https://trid.trb.org/View/2530107</link>
      <description><![CDATA[To investigate the drag reduction mechanism and variation in the efficiency of the air-bubbling system, the authors designed and conducted model ship experiments under an ice floe channel using a self-designed navigation device, force measurement system, camera observation system, and prototype of an air-bubbling system, based on a polypropylene non-refrigerated model ice. During the experiments, the navigation device allowed the ship to pitch, roll, and heave, while adjusting the air-bubbling system's gas flow rate, ship speed, and ice concentration to explore factors affecting the efficiency of the air-bubbling system. Building upon the model ship experiments, the authors further explored the drag reduction mechanism and effects of the air-bubbling system through coupled CFD-DEM numerical simulations. The research findings indicate that the drag reduction rate of the air-bubbling system decreases approximately linearly with increasing ice concentration and ship speed. Conversely, increasing the gas flow rate synchronously increases the drag reduction effect, albeit with a more pronounced marginal utility. Additionally, the authors conducted numerical calculations on the drag reduction rates of two additional ship types equipped with the air-bubbling system. Using multi-parameter linear fitting, the authors derived an empirical formula for estimating the drag reduction rate of the air-bubbling system under different conditions.]]></description>
      <pubDate>Tue, 13 May 2025 09:50:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2530107</guid>
    </item>
    <item>
      <title>Ice Resistance Calculation in Pack Ice Conditions</title>
      <link>https://trid.trb.org/View/1974335</link>
      <description><![CDATA[With the decline of the Arctic sea ice cover, more and more marine transportation and oil production are moving into ice-covered waters. Pack ice conditions may be the most common scenario for the ice-going ships in airworthiness seasons, except the icebreaker. During the ship advancing in pack ice conditions, the ice pieces will contact with the hull, interact with the water and even break or crush due to the bend stress, which is a complex process for the numerical simulation. In this study, the ice resistance of ship under the pack ice condition has been estimated using Multi-Material Arbitrary Lagrangian Eulerian formulation and penalty-based fluid structure interaction technique in LS-DYNA. Emphasis in present research has been placed on the hydrodynamic loads occurring during the ship-ice interaction in the numerical model without significant simplification. Validation of the employed fluid structure interaction model was given, especially focusing on the buoyancy and hydrodynamic behaviors of an ice cube. The ice pieces and the ship hull were assumed to be rigid. In addition, an ice filed generation algorithm to generate randomly distributed pack ices was adopted. Finally, the ice resistance of an oil tanker has been calculated and validated by comparing with the empirical formula. Moreover, the necessity to consider water effect in the interaction between ship and ice was discussed. When the hydrodynamic influence of ship is neglected, the ice resistance will be large obviously. In order to simulate the fracture behavior of ice, the material model such as cohesive element model was also considered.]]></description>
      <pubDate>Fri, 16 Aug 2024 10:17:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1974335</guid>
    </item>
    <item>
      <title>Investigation of ship resistance characteristics under pack ice conditions</title>
      <link>https://trid.trb.org/View/1751938</link>
      <description><![CDATA[Pack ice is a matter of considerable importance for ships and offshore structures operating in ice-covered waters. In particular, Arctic sea ice has been melting much faster recently than previously thought, with ships and offshore structures in Arctic regions and ice-covered waters being frequently exposed to pack ice conditions. Consequently, minimizing ice loads and ensuring safety under these conditions is a key consideration from a design perspective. This study aims to provide a better understanding of ship resistance characteristics and to investigate the factors that influence ship resistance when navigating pack ice fields. In the study, a preparation procedure for pack ice conditions for model testing in an ice tank is introduced, and some of the variables that can affect the ship resistance—channel width, broken ice floe size, ice concentration, and ice thickness—are considered in the experiments. The significance of each variable is discussed, and non-dimensional regression analysis is then applied to derive the relationships between the four variables and an equation for pack ice resistance prediction is established on the basis of this analysis. The reliability of the equation is verified by comparing the predicted results and the results of full-scale ice trials using the icebreaker Araon.]]></description>
      <pubDate>Mon, 30 Nov 2020 17:29:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1751938</guid>
    </item>
    <item>
      <title>2D Numerical Modeling of Icebreaker Advancing in Ice-covered Water</title>
      <link>https://trid.trb.org/View/1723372</link>
      <description><![CDATA[This paper presents a 2D numerical modeling to calculate removal and breaking of ice floes when an icebreaker advances into ice-covered water. The numerical simulation calculates repeatable ice-breaking and ice-removal in pack ice. The ice-breaking is calculated by a shipice contact detection and fluid-structural interaction of bending behavior of a plate ice. The iceremoval are calculated by a physically based modeling using 3DOF rigid body equations. A ship advances with a constant speed or constant thrust. A plate ice is broken by bending and splitting mode. The ice foes drift with constant force in which ice floes are assumed to be drifting by wind and current. An open channel caused by the ice-breaking and ice-removal by icebreaker are numerically obtained. A simulated ice channel after icebreaker's advancing into ice-covered water depends on the floe size as well as the ship’s rigid motion and ice drifting force. The numerical results show the proposed numerical model can be useful in order to identify an efficient way of ship handling in ice-covered water.]]></description>
      <pubDate>Fri, 31 Jul 2020 17:52:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1723372</guid>
    </item>
    <item>
      <title>Study on the Procedure to Obtain Attainable Speed in Pack Ice</title>
      <link>https://trid.trb.org/View/1723333</link>
      <description><![CDATA[Cost evaluation for voyage route planning in ice covered sea is one of the major topics among ship owners. Information of ice properties, such as ice type, concentration of ice, ice thickness, flexural strength of ice and speed-power relation in given ice properties, are very important to decide optimum route in cost perspective. To find procedure of attainable speed evaluation at any designated pack ice condition model test results of resistance, self-propulsion and overload test in ice and ice free water were used. Also calculation of net thrust and estimation of ice resistance by empirical formula were performed. All model tests were carried out in KRISO ice tank and towing tank. Combination of model test results and careful observation of underwater videos shows physical phenomena of underwater situation and suitable buoyancy and clearing resistance of empirical formula. Detailed description of determination of attainable speed in certain power and pack ice condition will be presented in this paper.]]></description>
      <pubDate>Fri, 31 Jul 2020 17:52:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1723333</guid>
    </item>
    <item>
      <title>Experimental and Numerical Investigation of Ship–Ice Interactions in Pack Ice</title>
      <link>https://trid.trb.org/View/1723331</link>
      <description><![CDATA[Ship–ice interaction in pack ice is important issue for safe ship operation in ice-covered water. This paper presents an investigation of ship–ice interaction when an ice-going ship turns and moves straight in pack ice. Free-running model tests were conducted to elucidate ship–ice interaction in pack ice. A 1/100 scale ship model and disk-shaped synthetic ice floes were used in a free-running model test. The model ship, propelled with a constant engine RPM at full loading condition, had a GPS and a motion sensor installed onboard to measure the ship’s trajectory and motion. Ice removal was measured using a vision inspection technique. In free running tests, the model ship passed through pack ice of three ice concentrations (10%, 20%, and 30%) with no rudder action. In turning circle tests, the model ship passed through pack ice with 7.2% ice concentration. The authors proposed a numerical model to calculate ice loads and ship motions in pack ice based on Discrete Element Method. To validate the numerical model, ship motions and ice removal in the model tests were compared with the simulations. Numerical results showed good agreement with experimental test results. The effects of ice concentration on ship–ice interactions were investigated experimentally and numerically.]]></description>
      <pubDate>Fri, 31 Jul 2020 17:52:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1723331</guid>
    </item>
    <item>
      <title>Fatigue Damage Calculation for Ship Hulls Operating in Pack Ice</title>
      <link>https://trid.trb.org/View/1722336</link>
      <description><![CDATA[Fatigue damage induced by ice loads is an important issue for ships operating in ice-covered waters. This paper shows the fatigue damage calculation of a ship structure navigating in pack ice fields due to ice loads based on a numerical simulation. A discrete element method (DEM) is employed to simulate the interaction between drifting ice floes and a moving ship. The simulation domain contains hundreds of circular ice floes with random size and distribution. A Weibull model can be used to describe the ice load peaks. The cumulative density functions of ice load peaks in different ice conditions (ice thickness and ice concentration) can be determined from a series of numerical simulation. The structural fatigue stress is determined using structural beam theory. According to the joint probability distribution of ice thickness and ice concentration and a proper S-N curve, fatigue damage can be estimated based on the Palmgren–Miner’s rule. An example of fatigue damage calculation is presented in this paper, and the calculated result reflects the fatigue damage due to ice-induced loads in pack ice is rather small.]]></description>
      <pubDate>Wed, 29 Jul 2020 16:09:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1722336</guid>
    </item>
    <item>
      <title>Measurement of Pack Ice Area and Concentration using Image Processing Package</title>
      <link>https://trid.trb.org/View/1722335</link>
      <description><![CDATA[Due to the increasing possibility of passing the Arctic route, considerable works on the icebreaking vessels have been continuously published. The model ship test on the pack ice model in the ice tank is actively carried out as a way to investigate the performance of icebreaking vessels. The concentration as well as the individual area of pack ice are important since they directly affect the performance. However, it is not easy to obtain those properties because not only the pack ice has uneven shape but also it keeps floating around in the ice tank. In this paper, an algorithm to identify the concentration of pack ice is introduced. From a digital image of pack ice obtained in the ice tank, the goal is to measure the area of pack ice using an image processing technique. Instead of the general global thresholding that yields numerical errors in this problem, a local thresholding technique, coupled with image subdivision based on the quadtree structure, is developed. The individual area of each ice patch is calculated using the edge extraction and the watershed technique.]]></description>
      <pubDate>Wed, 29 Jul 2020 16:09:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1722335</guid>
    </item>
    <item>
      <title>Experimental study of ship resistance in artificial ice floes</title>
      <link>https://trid.trb.org/View/1708949</link>
      <description><![CDATA[In this paper, a model-scale ship towing experiment is conducted to investigate the ship resistance in small ice floes. Instead of using refrigerated model ice, artificial ice floes made of Polypropylene (PP) is used in the tests based on the assumption that the dominant motion modes of small ice floes in water are rigid-body ones. The control parameters are further tailored to define the sizes and shapes of the artificial ice floes, whose specific compositions are determined based on the information from field observations. These ice floes are then randomly placed on the water surface in the Laboratory to approximate the realistic characteristics of ship resistance caused by small ice floes in practical conditions. The influences of Sea ice concentration, floes shapes and floes sizes on ship resistance vs velocity are investigated. Experimental results close to those obtained from other authors have been obtained, which indicates the feasibility of using PP-material artificial ice floes to measure ship resistance in waters covered with small ice floes subjected to low ice concentrations. Interesting phenomena observed in the experimental tests are also reported and analyzed.]]></description>
      <pubDate>Thu, 23 Jul 2020 16:16:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1708949</guid>
    </item>
    <item>
      <title>Ice Load Signatures for Ridge Actions on Wind Turbines With Conical Collars</title>
      <link>https://trid.trb.org/View/1718383</link>
      <description><![CDATA[Wind turbine structures are usually tall and slender. This makes them very susceptible to vibrations. To reduce vibrations in ice, conical shapes at the ice line which fail the ice in bending are often preferred. Conical shapes can be sloped either up or down. Ice loads from level ice can be shown theoretically to be lower for downward breaking. For design, the structural engineer requires ice load signatures (load vs time) to feed into dynamic structural analyses (in which the cyclic wind loads are also included). A method for synthesizing load signatures for sloping structures when subject to level ice is described in ISO 19906 and applied in this work to produce stochastic load-time series In recent years, there has been a move to extend wind turbines into deeper water and pack ice regions. A current project is to place turbines in Lake Erie beyond the landfast ice. In pack ice, ridges will usually dominate the ice loads. No guidance is provided in ISO 19906 either for the quasi-static ridge loads for downward breaking or for load signatures from ice ridges. In this work, ice load signatures are developed for the example structure first for level ice and the method further advanced to create ice load signatures for ridges. Example ice loads and ice load signatures for a downward breaking cone for level ice and ridges for a Lake Erie location are developed.]]></description>
      <pubDate>Wed, 15 Jul 2020 09:12:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1718383</guid>
    </item>
    <item>
      <title>Study of Ship Resistance Characteristics in Pack Ice Fields</title>
      <link>https://trid.trb.org/View/1718180</link>
      <description><![CDATA[During the melting seasons of the Arctic, the ice condition is quite similar to pack ice fields; thus, a major component of ship resistance arises from momentum exchange between the ship and the broken ice floe. In particular, ice concentration and thickness will lead to significant changes in the ship performance. The aim of this research is to understand ship resistance characteristics when navigating in pack ice fields and investigate the factors that influence of the magnitude of resistance in the model tests in an ice tank. Various channel widths, ice concentrations, and thicknesses are considered, and model tests were conducted in the Korea Research Institute of Ships and Ocean Engineering (KRISO) ice tank. In this paper, the test results are analyzed, and the ship resistance characteristics in pack ice are then discussed.]]></description>
      <pubDate>Wed, 15 Jul 2020 09:12:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1718180</guid>
    </item>
    <item>
      <title>Analysis of Pack Ice Deterioration Due to Wave Action on the Grand Banks, Spring 2017</title>
      <link>https://trid.trb.org/View/1717674</link>
      <description><![CDATA[The deterioration of pack ice due to wave action on the Grand Banks, offshore Newfoundland, is investigated. A description of wave effects on pack ice is provided that is based on the observations of one of the authors (JB) during several icebreaking voyages on the East Coast of Canada and in the Eastern Arctic. Sea ice deterioration in the region is observed to be dominated by swell wave action which extends to relatively long distances within the ice pack. Heat flux due to wave action is incorporated in an ice dynamics forecast model and used to evaluate the role of wave action on ice deterioration. A test case from the 2017 ice season is used to calibrate and examine the performance of the proposed formulation. The paper compares hindcasts of ice extent and concentration to observations. The results indicate that deterioration of the pack ice due to wave action is significant during severe storm conditions.]]></description>
      <pubDate>Wed, 15 Jul 2020 09:12:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1717674</guid>
    </item>
    <item>
      <title>Investigation of two pack ice besetting events on the Umiak I and development of a probabilistic prediction model</title>
      <link>https://trid.trb.org/View/1596852</link>
      <description><![CDATA[Pack ice besetting events are defined as incidents in which a typical ice-class vessel encounters dynamic sea ice conditions which are beyond the ship's icebreaking and maneuverability capacities, and the vessel becomes stuck in the pack ice until such conditions subside. Besetting events can cause severe disruption to a vessel's transit schedule, leading to increased operational downtime, and ship crew and fuel costs. Hence, predicting the probability of occurrence of these events can help vessel operators plan in advance accordingly, possibly rerouting the vessel, and saving operational costs. In this paper, two pack ice besetting events experienced by the Umiak I, an icebreaking bulk carrier owned and operated by Fednav Limited which runs nickel ore from the mine at Voisey's Bay, Labrador to Québec City, are analyzed in terms of the wind, surface ocean current, and sea ice conditions which caused them. The particular metocean and pack ice conditions associated with the occurrence of these events are used to develop a framework for a model to predict the future occurrence of such events for the Umiak I and quantify probabilities of besetting event occurrence linked to specific sets of coincident metocean and ice conditions. The model will serve as a tool for predicting besetting event probabilities during Umiak I navigations, as well as in hindcast shipping feasibility studies, to determine the likelihood of besetting for vessels with Umiak I capabilities in regions of new operations. The factors considered in this study are the vessel distance to the nearest coastline, regional wind and surface current speed, direction relative to the nearest coastline, divergence, and vorticity. The ice factors considered are the total concentration, mean thickness, and floe size (this represents a mean floe diameter). The datasets analyzed in this paper suggest the primary causes of the two besetting events experienced by the Umiak I in 2012 and 2013 were the relatively large ice floes encountered by the vessel (the majority of the floes during the besetting events were greater than 6 km in diameter), in combination with a convergent regional wind field and onshore winds and currents.]]></description>
      <pubDate>Tue, 30 Apr 2019 17:05:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1596852</guid>
    </item>
    <item>
      <title>Application of a Free Drift Tactical Ice Forecast Model in Pack Ice Conditions</title>
      <link>https://trid.trb.org/View/1566240</link>
      <description><![CDATA[The extension of oil and gas exploration in High Arctic offshore locations will likely require floating drilling capability in the presence of high-concentration sea ice (pack ice) at the beginning and end of the open water season. The detection and drift forecasting of potentially unmanageable ice features (PUIF) will be key components of an ice management system designed to manage risk while drilling during pack ice intrusions. In September 2015 during the Oden Arctic Technology Research Cruise 2015 (OATRC 2015), an ExxonMobil Upstream Research Company (EMURC) free drift tactical ice forecast model designed to forecast the drift of individual ice floes in low concentration ice conditions was applied in near real-time to high concentration pack ice with predominant thicknesses of medium first-year ice in the Arctic Ocean. The description and application of the proposed ice drift forecast model is presented in this paper. In addition, forecast results are compared to drift data collected during OATRC 2015. It is shown that the free drift forecasting tool produces reasonably accurate and useful forecasts in the high concentration ice observed.]]></description>
      <pubDate>Fri, 28 Dec 2018 14:03:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1566240</guid>
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