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    <title>Transport Research International Documentation (TRID)</title>
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    <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>MODEL TESTS ON HULL-DECKHOUSE INTERACTION</title>
      <link>https://trid.trb.org/View/163909</link>
      <description><![CDATA[To check a theory and formula proposed by H. H. Bleich on stress relationship of hull and house for vessels fitted with long deckhouses.  Theory based upon concept of separate house and hull bending with interaction strongly dependent upon vertical stiffness of support of house. Nine tests were performed upon a single 20-ft. aluminum model with three separate houses, fitted for simple variation of underdeck stiffness.  The hull of double-cell construction, connected by fitted bolts and high-torque bolts with houses 160 and 80 in. in length and demountable main deck equipped with simulated deck beams.  Design based upon proportionality of elastic action of ships and model with midship proportions in general conformance with passenger vessel practice.  Range of Bleich u value for nine tests representative of ship values to be expected.  Model loaded to give constant hogging moment throughout length of house.]]></description>
      <pubDate>Thu, 21 May 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/163909</guid>
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    <item>
      <title>A STUDY ON THE STRUCTURAL ACTION OF SUPERSTRUCTURES ON SHIPS</title>
      <link>https://trid.trb.org/View/162542</link>
      <description><![CDATA[Starting from the assumption that the hull and the deck house may be considered as beams, to each of which, separately, Navier's hypothesis is applicable, the report gives expressions for the deflections and stresses in the hull and deck house assuming constant section of hull and house; it is shown that the theoretical stress distributions found are of the type observed in the tests.  The results of this theory concerning the stresses in the mid-ship section can be arranged in simple tables which permit the prediction of the deviation from the conventionally assumed straight-line stress distribution.  The method is equally applicable if a part or all of the deck house consists of aluminum.]]></description>
      <pubDate>Wed, 18 Feb 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/162542</guid>
    </item>
    <item>
      <title>GLOBAL VIBRATION IN A CHEMICAL TANKER: A DESIGN AND SEA TRIAL STUDY</title>
      <link>https://trid.trb.org/View/159859</link>
      <description><![CDATA[The importance of a good vibration climate on board ships is now generally recognised.  This is reflected in the increasing number of national and international standards and regulations being put forward in this respect.  Against this background it is becoming more and more common at the design stage to focus attention on both the propeller pressure impulses and the dynamic response of the hull girder and superstructure.  If such investigations and calculations show that resonant frequencies of the structures are avoided in the service speed range, and if the excitation forces are kept at acceptable levels, the risk of unpleasant vibration levels will certainly be greatly reduced.  A design stage vibration study according to the above has been carried out for  a 33,000 tonne d.w. chemical tanker built at Sarpsborg Mekaniske Verksted A/S, followed by full scale measurements during the ship's sea trial.  The results of the investigation are presented in the following report by Kristian Evensen, project engineer, Det norske Veritas (Maritime Advisory Services).  The survey shows that the finite element approach to these problems is very powerful and can compute the natural frequencies of the hull girder and the superstructure with acceptable accuracy.  The calculation of the forced response level is somewhat more complicated because the result depends not only on the factors determining the natural frequencies but also on the computed excitation forces and the damping chosen for the vibrating system.  It is concluded that a vibration prediction program as described should be of great benefit for shipyards and shipowners in their aim of reduced vibration levels onboard future ships as demonstrated in the present case.]]></description>
      <pubDate>Wed, 08 Oct 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/159859</guid>
    </item>
    <item>
      <title>VIBRATIONS IN THE SHIP'S HULL</title>
      <link>https://trid.trb.org/View/153355</link>
      <description><![CDATA[This article deals with the response of ship superstructures to vibrations in the hull.  In a 6-year study Det norske Veritas measured vibrations in the aftership of more than 100 vessels and from this it was seen that 50 had unacceptable levels of vibration in the superstructure.  Of these vessels 80% showed the propeller as the single major source of excitation.  In 31 of the 50 ships the problem was one of localised vibration of the deck of bulkhead and in most cases was solved by local stiffening, but for 17 of those remaining, the problem was one of global vibration of the hull and superstructure which would be costly to eliminate but which could have been avoided through greater effort and calculation at the design stage.  Examples of analysis are given for four different types of merchant ship and the article concludes that experience has shown it possible to completely eliminate or reduce the degree of vibration in hull and superstructure if one reduces excitation forces to a minimum, takes into account the problem of vibration during the construction of the superstructure and supports, and guards against excitation to the superstructure's natural frequency and to hull-induced resonance frequencies.  Order from BSRA as No. 52,364.]]></description>
      <pubDate>Wed, 07 May 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/153355</guid>
    </item>
    <item>
      <title>A PARAMETRIC STUDY ON GLOBAL HULL AND SUPERSTRUCTURE VIBRATION ANALYSIS BY MEANS OF THE FINITE-ELEMENT METHOD</title>
      <link>https://trid.trb.org/View/83610</link>
      <description><![CDATA[This study presents a number of parametric variations on the finite-element modelling of ships for global hull and superstructure vibration analysis.  The parameters studied are the effects of double bottom vibration, shear lag in the double bottom, the influence of the hull girder on the fundamental superstructure natural frequency, the effect of load condition, i.e. mass distribution, and the effect of the distribution of propeller-induced hull surface pressure field on the forced vibration level.  The lower natural hull frequencies are compared with results by the classical Timoshenko beam and with measurements.  A design study is carried out to change the natural frequency of a superstructure.  Two ships are studied, a 60,000-dwt bulk carrier and a 12,500-dwt multipurpose carrier.  Order from BSRA as No. 50,008.]]></description>
      <pubDate>Sat, 26 May 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/83610</guid>
    </item>
    <item>
      <title>DYNAMIC RESPONSE OF HULL AND SUPERSTRUCTURE. CORRELATION STUDY BETWEEN MEASURED AND CALCULATED VIBRATION</title>
      <link>https://trid.trb.org/View/85483</link>
      <description><![CDATA[Two detailed investigations of the dynamic response of hull and superstructure of a 56400 dwt and a 138000 dwt tanker are presented.  Three-dimensional finite element models are considered for the symmetric half ship of hull and superstructure.  Order from NSFI as No. 16340.]]></description>
      <pubDate>Wed, 25 Apr 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/85483</guid>
    </item>
    <item>
      <title>DESIGN STAGE CONSIDERATION (OF VIBRATION)</title>
      <link>https://trid.trb.org/View/75762</link>
      <description><![CDATA[In this paper DnV experience of vibration problems from the design stage to full-scale measurement is summarized. Wherever possible, a review of the plans at the early design stage should be made.  This may pin-point the areas of particular importance where further investigations are necessary.  Both excitation sources and responses, i.e. global vibration of hull and superstructure and local vibration of decks and bulkheads are considered.  The problems are discussed from the point of view of human suspectibility and fatigue cracks.  In conclusion, some examples of the use of simple calculation methods and empirical data are given.  The necessity of extensive finite element investigations for particular parts of the structure is mentioned.  Order from: BSRA as No.  49,081.]]></description>
      <pubDate>Thu, 12 Oct 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/75762</guid>
    </item>
    <item>
      <title>STRUCTURAL VIBRATION CALCULATIONS</title>
      <link>https://trid.trb.org/View/75745</link>
      <description><![CDATA[Computerised numerical methods such as the Finite Element Method have extended the possibilities for complex structural vibration calculations considerably.  However, as the calculation costs should always be weighted against the need for accuracy, classical anaytical methods are still of importance in the study of simple structures.  Calculation of global hull and superstructure vibration as well as local vibration is discussed with emphasis on solutions by means of the Finite Element Method.  Different method techniques for global vibration analysis are discussed.  A number of examples are presented, and some comparisons are made between simple analytical solutions and Finite Element solutions.  Order from: BSRA as No. 49,084.]]></description>
      <pubDate>Wed, 27 Sep 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/75745</guid>
    </item>
    <item>
      <title>VERIFICATION OF METHODS (FOR DETERMINING VIBRATION)</title>
      <link>https://trid.trb.org/View/75748</link>
      <description><![CDATA[In this paper the correlation between measured and calculated hull and superstructure response is considered. Three different examples are presented, showing that the main resonant frequencies may be predicted with sufficient accuracy at the design stage.  This makes it possible to select a proper propeller blade frequency and hence to reduce considerably the risk of unpleasant vibration.  The problems of energy transport or effective excitation forces are discussed, and it is concluded that with the methods available at the moment, the calculated response will only give an indication of the global response level.  Finally, some recommendations of further investigations into the problems of ship vibration are given and the present efforts of Det Norske Veritas in this field are outlined.  Order from: BSRA as No. 49,086.]]></description>
      <pubDate>Wed, 27 Sep 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/75748</guid>
    </item>
    <item>
      <title>PREDICTION OF VIBRATION IN THE AFTERBODY OF SHIPS</title>
      <link>https://trid.trb.org/View/73462</link>
      <description><![CDATA[The prediction of dynamic response in the afterbody of ships by means of a finite element formulation is discussed.  The sub-space iteration method for solving the eigenvalue problem is found to be very efficient even when a reasonably large number of natural frequencies is present.  For the forced vibration of large structural components in the afterbody such as superstructure, aft end and funnel satisfactory accuracy has been found by including only the after part of the hull in the model.  It is concluded that high priority should still be given to verification of predictions by exciter tests on ships.  The finite element calculation is, however, considered to be a very useful tool when alternative structural configurations are compared at the design stage.  The effort and cost involved should by no means be prohibitive for the type of modelling discussed in this paper.]]></description>
      <pubDate>Wed, 28 Jun 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/73462</guid>
    </item>
    <item>
      <title>PROBABILISTIC DESIGN CONCEPTS IN STRUCTURAL SAFETY AND RELIABILITY</title>
      <link>https://trid.trb.org/View/57541</link>
      <description><![CDATA[Structural reliability and safety concepts have been studied deeply and applied to many civil engineering structures such as buildings, bridges, towers and dams.  These concepts have been used successfully in other fields also, principally in aeronautics and aerospace, automobiles, and trains.  In naval architecture, little has been done in this area despite the obvious randomness of the variables involved in the design of a marine vehicle, particularly with regard to sea loads.  This paper presents a comprehensive probabilistic model for formulating structural design criteria in ships.  It covers the overall structural strength of ships under the random sea loads from a probabilistic point of view.  A risk measure that accounts for the uncertainties associated with the design variables involved in the structural aspects is described.  A method for a systematic analysis of these uncertainties and their effects on the calculated risk is given.  The application of the long-term and short-term design criteria on a Mariner ship is illustrated as an example, and compared with the conventional safety factor of the deterministic approach.]]></description>
      <pubDate>Thu, 16 Feb 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/57541</guid>
    </item>
    <item>
      <title>ON THE STRESS DISTRIBUTION AT THE BASE OF THE FRONT CORNERS OF ACCOMMODATION STRUCTURES</title>
      <link>https://trid.trb.org/View/67197</link>
      <description><![CDATA[The accommodation structure of a ship is generally arranged at the stern.  Longitudinal bending moments give little effect there.  However, corners of the fore end where the accommodation structure is connected with the main hull are still subjected to high concentrated stress due to discontinuity of the structure.  Though the rounded corner of the fore end wall is known to relieve the stress, a right-angle structure has lately been adopted, mainly for the convenience of work, but it has caused damages to the front corners on several ships.  To clarify the relations between the corner shape and stress distribution by the longitudinal bending of the ship, a study is made of eight types of corner shape by finite element method.  The results have shown that the maximum stress decreases by 40 percent on rounded corners from that on right-angled corner.  It is also found that the knuckle type corner with straight line is as effective as the rounded type in relieving stress. The availability of longitudinal and transverse brackets for right-angled structures and the relations between bracket size and the degree of stress relief are also investigated.]]></description>
      <pubDate>Wed, 13 Apr 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/67197</guid>
    </item>
    <item>
      <title>STRUCTURAL INTERACTION BETWEEN SHIP'S HULL AND SUPERSTRUCTURE</title>
      <link>https://trid.trb.org/View/44931</link>
      <description><![CDATA[The problem of interaction between ship's hull and superstructure is complicated by various non linear effects, such as shear lag in both hull and superstructure, deformation or slip in the connection between superstructure and upper deck and differential curvature between hull and superstructure due to the flexibility of the upper deck. These effects are not usually considered in conventional strength calculations.  This paper gives a method for calculating deflections and stresses in the hull and superstructure taking account of all various factors influencing the deckhouse and superstructure characteristics.  The problem is discussed in a general way and presented in simple stiffness concept form as the finite strip method being applied with certain assumptions.  The paper also includes a study on the object of superstructures and deckhouses effective breadth and efficiency and how it contributes to the longitudinal strength of ships.]]></description>
      <pubDate>Fri, 14 May 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/44931</guid>
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