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Effects of geometric imperfections on the strength of composite panels in ship hulls
AuthorsK Misirlis ; J Downes ; R S Dow
Date published2009
AbstractA numerical investigation on the effects from initial imperfection shapes on the strength of long fibre-reinforced composite panels is presented in this paper. Fourteen alternative initial geometric imperfections are imposed in long plates for two alternative lay-up configurations; a tri-axial and a balanced woven roving configuration. The sectional response is investigated with nonlinear finite element analysis which incorporates a progressive failure model for the degradation of the material properties. For the analysis both thick and thin panels are considered with breadth to thickness ratios of 10 and 50 respectively. The comparison focuses on the effects on stiffness and ultimate strength of the panels and uses as a basis the preferred buckling mode imperfection for each lay-up configuration. Results demonstrate a conservative approach when adopting the preferred buckling mode shape for overall initial imperfections and a significant reduction on performance from localised imperfections.
AuthorsK Misirlis ; J Downes ; R S Dow
Date published2009
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Full-scale trials in varying depths of water on a King Class fast patrol vessel
AuthorsC Thew
Date published1988
AbstractA paper describing the full-scale trials carried out on a Royal Hong Kong Police `King Class' 26m semi-planning fast patrol boat at various depth/draft ratios between 2.96 and deep water over a range of Froude numbers between 0.3 and 0.8. Results are also given in one location for the effect on performance of varying displacement and for both inward and outward turning propellers. Reference is made to previous comprehensive trials carried out at the turn of the century on the HDMS Makrelen Sobjornen S.119 and HMS Cossack. Data are presented to enable preliminary powering calculations based on published information and that given in this paper. Finally comments are made on the present model tank and theoretical procedures for power predictions for this type of craft.
AuthorsC Thew
Date published1988
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Full-scale Trials on a Small High Speed Naval Craft With Focus on Slamming
AuthorsA Rosen ; O Rutgersson
Date published1998
AbstractAs a part of a co-operation project between the Division of Naval Architecture at KTH Stockholm and the Swedish Defence Material Administration full-scale trials have been performed on a small naval craft in rough seas. This paper is the first presentation of these trials. Characteristics of impacts puls lengths and rise times are discussed. Comparison is made between statistical distributions of peak values and therefrom derived Rayleigh distributions. A brief study is made on filtering of acceleration recordings. The results are used to verify computer simulations indicating that bow seas would give higher pressure magnitudes than head seas. Practical problems related to this kind of full-scale tests are discussed for example operational considerations when determining extreme levels for design criteria. Areas of further studies are exemplified e.g. simulations and correlations between pressure accelerations and structural response.
AuthorsA Rosen ; O Rutgersson
Date published1998
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Marine Accident Investigation Branch (MAIB) Report of the investigation into the lifeboat accident on board MV Hoegh Duke at Surabaya Sumatra on 20 August 1992
AuthorsMAIB
PublisherDepartment of Transport (DOT)
AbstractSix seaman were killed and the six others hospitalised when the aft hook slipped off its davit fall lifting ring as the starboard lifeboat was being lowered into the water. Recommendations of the report include advice to the managers Leif Hoegh & Co to improve safety on all their vessels and the need to review the use of on-load release hooks.
AuthorsDate publishedMAIB
1994
PublisherDepartment of Transport (DOT)
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On the prediction of hydrodynamic forces acting on a ship moving at constant drift
AuthorsN Sulficker Ali ; G Dhinesh ; K Murali et al.
Date published2005
AbstractEffects of incidence angle are important for all types of structures and vehicles including those for land sea air and space. Force and moment data for various angles of incidence play an important role in design. The effect of drift angle on a ship is investigated through towing tank tests and using CFD (computational fluid dynamics). Resistance and wave elevations obtained from the computational study are validated with experimental results. Detailed free surface mean velocity and pressure flow fields on the hull surface are obtained from the computational study for Fn ranging from 0.16 to 0.22 and for drift angle ß =0 5 and 100. The lateral force yaw moment and asymmetric flow characteristics are brought out in the computational study.
AuthorsN Sulficker Ali ; G Dhinesh ; K Murali et al.
Date published2005
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Safety at Sea Proceedings of the Second West European Conference on Marine Technology (WEMT) 23-27 May 1977
AuthorsWEMT
Shelf Location213e
AbstractConf held in London May 23 - 27 1977 Papers are Legislating for safety Analysis of world merchant ship losses 1967 - 1975 Structural design - safety and reliability considerations behind the classification society requirements IMCOs activities with particular reference to the impact on ship design Why unsafety at sea Safety art at sea - a problem of risk management New outlooks for guardians of safety - explicit versus implicit risk analysis on classification/ certification Automation and ship safety Stability of ships safety from capsizing and remarks on sub division and freeboard The prevention of cargo fires and explosions in oil tankers Lifeboats survival craft and launching methods Human factors in shiphandling Collision avoidance by manoeuvre The influence of navigational aids on traffic behaviour in converging areas in the entrance/exit of the English Channel Training for safety at sea On ship manoeuvrability and collision avoidance
AuthorsPublisherWEMT
Gresham Press
Shelf LocationDate published213e
1977
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Study of "re-melt" temper bead and polarity effects on porosity in the under freshwater wet welds
AuthorsEzequiel C P Pessoa ; Alexandre Q Bracarense ; Stephen Liu et al.
Date published2004
AbstractThe objective of this work is to discuss the influence of electrode polarity on bead-on-plate (BOP) welds and re-melt temper bead on the pores behaviour in the weld bead section of bead-on-grove (BOG) and bead-on-bead (BOB) welds. This article describes a study of the polarity effect in the underwater wet welding comparing the bead shape porosity arc stability and pores location in welds made with E6013 electrode at 50 and 100 meters depth under fresh water.
AuthorsEzequiel C P Pessoa ; Alexandre Q Bracarense ; Stephen Liu et al.
Date published2004
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Study on the learning method suitable for the engine room simulator based on personal computer
AuthorsKenji Ikenishi ; Toshio Hikima ; Tran Hong Ha et al.
Shelf Location213c
AbstractAlthough a lot of research has been carried out on the hardware of the pc-based ERS (engine room simulator) there is little research on the educational method using them. The first phase involved carrying out education and training by the discovery learning and the instruction learning and investigated learning outcomes. The results are described from considering the following matters: relation between the learning method and learning outcomes; the type of the error that students tend to commit; influence of the application order of the learning method; an instructor's role in the individual learning; improving points for increasing learning outcomes.
AuthorsDate publishedKenji Ikenishi ; Toshio Hikima ; Tran Hong Ha et al.
2004
Shelf Location213c
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The features of functional dependencies of wing's aerodynamic characteristics on their motion parameters and orientation relative to ground surface. The analytical representation of the airfoil outline and influence of the outline form on the aerodynamic
AuthorsV I Yushin
Date published2000
AbstractThe features of functional dependences of wings' aerodynamic characteristics on their motion parameters and orientation relative to the ground surface are considered. The basic methods for obtaining a WIG craft's aerodynamic characteristics are experimental and calculation methods which require the results to be represented as a finite number of loads and moments for specified parameters of orientation and motion of the craft relative to the ground surface. The analytical representation of the airfoil outline and the influence of the outline form on the aerodynamics of wings moving near the ground are discussed.
AuthorsV I Yushin
Date published2000
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The International Committee on Seafarers' Welfare: ILO convention 163 and recommendation 173
AuthorsR Rodriguez-Martos Dauer
Date published2005
AbstractWelfare facilities are sometimes still seen by some as something generous and philanthropic rather than as a necessary condition for maintaining a healthy efficient and safe crew. ILO convention 163 and recommendation 173 were adopted in 1987 as a response to the needs of welfare facilities on board vessels and in port. All those countries that ratified it assume responsibility for taking care of the welfare of any seafarers on board any vessel in their ports on board their own national ships. The development of this convention and recommendation are described in regard to the International Committee on Seafarers' Welfare created as an international umbrella organisation dedicated to the practical implementation of the International Labour Organisation instruments on Seafarers' Welfare.
AuthorsR Rodriguez-Martos Dauer
Date published2005
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Effect of seaward side wave screens on the dynamic pressures on a vertical wall
AuthorsBalaji Ramakrishnan ; Sundar Vallam
Date published2002
AbstractThe performance of two vertical wave screens formed by pipes on reducing the pressures due to waves on a vertical wall placed on its leeward side has been investigated through an experimental program. The variations in the reflection characteristics of the wall are also studied. Of the two screens the porosity of the seaward side screen was maintained constant while the porosity of the one in between this screen and the wall was varied. Thus four different screen porosity combinations in a random wave field were studied. The effects of the screen porosity on the reflection from the wall and the dynamic pressures on the vertical wall have been reported as a function of relative dissipating chamber width. The details of models instrumentation analysis of the data and the results are presented and discussed in this paper.
AuthorsBalaji Ramakrishnan ; Sundar Vallam
Date published2002
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Research on calculation method and simplified on-board measurement of NOx-emission from marine diesel engine
AuthorsYin Zibin ; Wu Guitao ; Dai Leyang
Date published2004
AbstractFor meeting the requirements and the characteristics of the on-board test of NOx-emission from marine diesel engines a new calculation method different from IMO's methods is put forward. An approximate calculation methods based on the new method and simplified measurement are also discussed. The calculation example and error analysis indicate the correctness of the new method and the feasibility of simplified on-board measurement of NOx-emission. The on-board test of NOx-emission becomes more practical and feasible by using handy gas analyzer.
AuthorsYin Zibin ; Wu Guitao ; Dai Leyang
Date published2004
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Numerical study of flow-induced vibration in pipeline on offshore platform
AuthorsDezhong Li ; Ning Mei ; Defu Liu et al.
Date published2002
AbstractThe flow-induced vibration often occurs in the pipelines on offshore platforms when they are used to convey oil in high fluid pressure and there are many undesirable geometric shapes such as too many bends and large variation sections in pipelines on offshore platforms. There are few studies on the vibration of oil-conveying pipelines on offshore platforms. The mechanism of vibration induced by flow in the oil-conveying pipelines on offshore platforms is analysed. Based on the theory of oscillating fluid mechanics mathematical models of unsteady incompressible viscous vibrating flow are established. The expressions for differential coefficients of velocity and pressure in flow are derived according to the parametric polynomial method. The velocity and pressure distributions in flow in the different conditions are obtained. The results show that flow behaviours of flow-induced vibration are affected by pipe structure and properties of fluid. Comparison between numerical result and variational solution shows a good agreement. The method for studying flow-induced vibration in oil-conveying pipeline on offshore platform is shown to be effective.
AuthorsDezhong Li ; Ning Mei ; Defu Liu et al.
Date published2002
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Second report on explosions in very large tankers
AuthorsInternational Chamber of Shipping
Shelf Location227f
AbstractFollowing explosions on three very large tankers in December, 1969, ICS set up a Tanker Safety sub-committee to co-ordinate and evaluate various investigations being conducted on a world-wide basis into the possible causes of these incidents. An interim report was issued on 1st December 1970. The suggestions on tank washing procedures under various tank atmosphere conditions made in the interim report still stand. As shown in the first report, research was initially concentrated on a number of possible sources of ignition in the 1969 explosions. The results of this research can now be said to justify, on a basis of very low probability, the discontinuance, as far as the December 1969 explosions are concerned, of further consideration of the following: impact sparking; compression ignition; auto-ignition by steam heating coils; pyrophoric ignition; R.F. induced current. In research of this nature, which is yet to be finalised, it is inevitable that certain statements are made which might well have to be amended in the light of further confirmatory work. Statements made in this report are therefore subject to this proviso and are based on the best information available at the present time.
AuthorsPublisherInternational Chamber of Shipping
International Chamber of Shipping
Shelf Location227f
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Report of the Advisory Group on Shipbuilding on the Upper Clyde
AuthorsDepartment of Trade and Industry
PublisherHMSO
AbstractReturn to an Address of the Honourable the House of Commons dated 29th July 1971 for 'Return of the Report of the Advisory Group on Shipbuilding on the Upper Clyde'
AuthorsDate publishedDepartment of Trade and Industry
1971
PublisherHMSO
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Laboratory experiments on the hydrodynamics of waves on adverse currents
AuthorsL Cappietti
Date published2003
AbstractA series of laboratory experiments was conducted in a flume to study the effects of adverse currents on regular and irregular waves. The transformation of regular and irregular waves on a sloping bed was studied with and without currents. Effects of the currents on the waves transformations are reported. After some introductory information the experiments are described. Next the results are considered.
AuthorsL Cappietti
Date published2003
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The consequences of environmental requirements on fuel oil specifications and on shipping operational costs
AuthorsP Melissen ; M van Mourik
PublisherIMarE Conferences and Symposia
AbstractThis paper describes the consequences of increased fuel costs on the operational costs of ships. Indicative calculations on shipping transport costs are made with references to the different types of shipping markets affected by increased fuel costs and to what extent these increases could be passed on to the users of shipping services. The impact of environmental legislation is examined regarding desulphurisation of crude oil and the additional of heavy metals to low quality bunkers. Bunker price fluctuations over the last two decades are also examined.
AuthorsDate publishedP Melissen ; M van Mourik
1993
PublisherIMarE Conferences and Symposia
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Ice and earthquake loads on a structure in the Okhotsk Sea - annual report of the JOIA Project FY1999
AuthorsKazuyuki Kato ; Yasumi Toyama ; Yutaka Yamauchi et al.
Date published2001
AbstractJapan Ocean Industries Association (hereafter JOIA) has been organizing the research project "Study on Ice Load Acting on Marine Structures" since the fiscal year of 1993. In this paper the studies evaluating effects of ice cover on an earthquake load which are part of the studies during FY1999 carried out by the project are briefly described. Also some results from the studies on "an earthquake under a stable ice cover condition" and the magnification of earthquake load under such condition are introduced. In addition study on the magnification of earthquake under a drifting ice cover condition is reported.
AuthorsKazuyuki Kato ; Yasumi Toyama ; Yutaka Yamauchi et al.
Date published2001
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International symposium on fire safety of ships Vol 1
AuthorsIMO ; HMMM
Shelf Location223a
AbstractInt Symp held in Piraeus Greece on 9-11 May 1990 Papers are The human element in fire safety of ships Fire in ships Fire-the most feared word aboard ship NFPA marine fire protection Strategies for firefighting and design for computer models Explosion hazards due to fire on ships IMO and fire protection of ships Application in practice of the present SOLAS - requirements of structural fire protection Negative ship stability effects of flooded compartments due to fire fighting Machinery installations extinguishing media on fires Fire in the scavenging manifold of the marine main diesel engines Fire protection of car ferries-practical assessment of safety systems on ships Fire safety in ships accommodations Fire protection of ports Fire and the electrical installation Electrical cables aboard ship-a fire hazard Prevention of fire spreading in marine HVAC-plants of passenger ships Fire insulation on board ships The use and advantages of ceramic fibre systems for passive fire protection of marine shipping Construction fire protection doors Professional fire rescue and safety services from Unitor
AuthorsPublisherIMO ; HMMM
Hellenic Institute of Marine Technology
Shelf LocationDate published223a
1989
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Laboratory performance analysis comparison of on-board marine cylinder oils
AuthorsNaoyuki Ohno ; Haruo Miyano ; Keishi Kuwada et al.
Date published2004
AbstractOf the lubrication oils used on board cylinder oil for a low-speed two-cycle diesel engine must endure the most severe conditions. Since cylinder oil is commonly used for the propulsion engine quality and performance of the cylinder oil have a great and direct effect on the safe operation of a vessel. Meanwhile ship owners are interested in reducing the consumption of cylinder oil. Laboratory tests on nine brands of cylinder oil from different companies which are currently used on vessels were carried out to evaluate the performance of the oils. Tests and analysis on heat-resistant characteristics such as oxidisation stability tests panel-cooking tests evaporation tests and TG-DSC (thermogravimetric -differential scanning calorimeter) analysis were carried out in addition to general analysis (of density kinematic
AuthorsNaoyuki Ohno ; Haruo Miyano ; Keishi Kuwada et al.
Date published2004