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Influence of moisture and low temperature on notched izod impact toughness in a pultruded reinforced composite
AuthorsK G Kellogg ; A R Kallmeyer ; R B Chinnam et al.
Date published1999
AbstractA preliminary assessment is made of the influence of low temperature on the impact-generated fracture of a commercial glass-reinforced polymer composite produced by the pultrusion process. Impact tests are conducted using an Izod testing machine on the composite specimens with a V-notch resulting in a fracture surface parallel to the fiber direction. An attempt is made to review the existing data in the literature on low temperature fracture behaviour of composites and compare the data obtained from these tests.
AuthorsK G Kellogg ; A R Kallmeyer ; R B Chinnam et al.
Date published1999
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Influence of the ballast tanks loading on the allowable VCG in damage case
AuthorsGuilherme Rueda ; Bruno Madella ; Kazuo Nishimoto et al.
Date published2005
AbstractThe AVCG (allowable vertical position of the centre of the gravity) of a unit informs for each draft the VCG limit that fulfils some requirements in case intact and damage stability requirements according to the ABS rules. The AVCG in mono-column offshore platforms is studied. As a case study the MonoBR an innovative conceptual unit developed by a partnership of PETROBRAS-CENPES and University of Sao Paulo was analyzed. The studies were carried out during the design of MonoBR for the Walker Ridge area Gulf of Mexico. The effect on the stability of the unit caused by a damaged tank depends on its loading condition since there is loss of both buoyancy and mass modifying the unit's displacement and centre of gravity. In other words depending on the tank loading the amount of water that enters or leaves the unit in a damage case may vary widely. Here the methodology is presented that is adopted in the study of the influence of the ballast tanks loading in the AVCG curve in MonoBR
AuthorsGuilherme Rueda ; Bruno Madella ; Kazuo Nishimoto et al.
Date published2005
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Influences of HAZ Characteristics on CTOD Toughness Variation in Multi-Pass Welded Cryogenic Steel
AuthorsJ-i Jang ; J-B Ju ; D Kwon et al.
Date published2000
AbstractThe present study is focused on the influence of heat-affected zone (HAZ) characteristics on crack tip opening displacement (CTOD) toughness variation of QLT (quenching lamellarizing and tempering) 9% Ni steel HAZ. It is well known that the CTOD test widely used for HAZ toughness evaluation is very sensitive to various HAZ properties which are mechanical and metallurgical. So this study aims to investigate the effective factors such as strength mismatching effects and microstructures distribution including LBZ (local brittle zone) in crack tip front and their influences on CTOD toughness variation. To estimate the influence of the factors more systematically K-grooved HAZ specimens are prepared for CTOD tests and analyzed after the tests.
AuthorsJ-i Jang ; J-B Ju ; D Kwon et al.
Date published2000
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Information Management and the World Wide Web - Reflections on the Experience of Managing a Large Institutional Website
AuthorsR Moreton ; J Wallis
Date published2000
AbstractThis paper sets out to address the issues concerned with improving access to the corporate information resource and builds on a paper by Moreton (1996). This original paper was derived as a result of a research project funded by the CSC-Index Foundation. The current paper reflects on the lessons learned from over three years' experience of running a large institutional (University) website and draws on past research into managing non-WWW information in a distributed systems environment. In particular the paper addresses the two significant issues of the adoption of Consolidated Approach to Information Management and the definition of Two Level Technical Infrastructure. Then the implications are considered of what needs to be done both technically and organisationally to manage the corporate information resource so that it can be more readily available to business users of desk-top computing devices.
AuthorsR Moreton ; J Wallis
Date published2000
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Measurements of cross-shore sand fluxes on a macrotidal pocket beach (Saint-Georges Beach Atlantic Coast SW France)
AuthorsCorinne Corbau ; Paolo Ciavola ; Ramon Gonzalez et al.
Date published2002
AbstractData on cross-shore sand transport was obtained during two tidal cycles on a dissipative macrotidal pocket beach in the outer Gironde Estuary (SW France). Sediment samples were collected using streamer traps at different elevations above the bed across the surf zone while measuring nearshore waves and cross-shore currents on the beach. The streamer tap was chosen because it appeared suitable to analyse the vertical grain size distribution in the water column during transport and time variations in onshore sediment fluxes. After some background information a look is taken at the study area followed by the methods. Next results are discussed.
AuthorsCorinne Corbau ; Paolo Ciavola ; Ramon Gonzalez et al.
Date published2002
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On performing short circuit studies on ship electric energy systems
AuthorsE Sofras ; J Prousalidis
Date published2005
AbstractNowadays the AES (all electric ship) concept with electric propulsion and electronic automation dominates components onboard. This extensive electrification of shipboard installations has increased the importance of certain types of electrical studies even at the ship design stage. A comparative analysis (both qualitative and quantitative) of a specific case study between IEC 61363 and IEC 61909 is presented highlighting points of convergence and divergence between them and underlining certain critical issues that have emerged. The results of this have been applied to the medium voltage electrical power system of a ship with electrical propulsion. This ship is a car or passenger ferry called 'ALKYON 2000'. The results and the differences in percentages between the resultant magnitudes are categorised and tabulated.
AuthorsE Sofras ; J Prousalidis
Date published2005
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On the drift speed of floating bodies in waves
AuthorsKatsuji Tanizawa ; Makiko Minami ; Taiji Imoto
Date published2002
AbstractThe wave drift speed of a floating body is discussed. Measurements of wave drift speed were carried out on both 2D floating body and a 3D floating body. Then an estimation method of wave drift speed was derived from the analysis of measurement results. The mechanism of wave drift speed varies with wavelength. In short wave range wave drift force due to wave scattering pushes the floating body. Therefore drift speed is decided by the equilibrium of wave drift force and fluid drag and it is proportional to the wave slope. In long wave range on the other hand wave drift force hardly acts on the floating body because wave almost transmits the floating body. Therefore the drift speed is decided by the wave-current speed and it is proportional to the square of the wave slope. Taking these wave drift mechanisms into consideration an estimation method of wave drift speed which covers entire wave range is proposed.
AuthorsKatsuji Tanizawa ; Makiko Minami ; Taiji Imoto
Date published2002
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On the mechanics of ice load on ships in level ice in the Baltic Sea
AuthorsPetri Varsta
Shelf Location230a
AbstractThis thesis analyses the mechanics of the ice load induced by level ice-ship interaction and develops a mathematical model for the load. The ice pressure which loads the ice wedge originates from the contact process between the ice edge and the ship hull. The dynamic bending of the ice plate induced by the contact force determines the ice load. The mechanical constants of the ice form the basic data for the analysis. The mathematical model forms a basis for future ice load measurements with which values for ship design can be gathered.
AuthorsPublisherPetri Varsta
Technical Research Centre of Finland
Shelf LocationDate published230a
1983
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Preparing for the impacts of climate change on the central south coast of England: a framework for future risk management
AuthorsAdam Hosking ; Robin McInnes
Date published2002
AbstractSCOPAC (Standing Conference on Problems Associated with the Coastline) commissioned a research study entitled "Preparing for the impacts of Climate Change". This study's aims were to develop climate change scenarios for the next 80 years identify generic impacts on the coast determine hazard and risk along the SCOPAC coast and identify future risk management requirements. The climate change scenarios are outlined. However particular concentration is given to geomorphological assessment of impacts upon coastal landforms and systems. Also the potential impacts on risk management and the key recommendations and conclusions of the study are looked at briefly.
AuthorsAdam Hosking ; Robin McInnes
Date published2002
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Pressures on pile-supported quadrant front-face breakwaters
AuthorsV Sundar ; B V V Subba Rao
Date published2001
AbstractBreakwaters are most important harbour structures designed to withstand and dissipate wave energy. They provide the required tranquillity conditions on their leeward side for safe marine operations and they intercept the movement of longshore sediment and prevent sediment deposition inside the harbour. Different types of breakwaters are being developed worldwide to suit the marine environment. Pile breakwaters consist of closely spaced rigid vertical piles. Vertical and horizontal slotted screens have also been used to form breakwaters. One type of breakwater configuration is a quadrant front face supported on piles with its leeward side permitting the berthing of vessels which is not possible with the presence of conventional rubble round breakwaters. Investigation of reflection transmission and loss coefficients of this model are presented and discussed as well as the pressures exerted on the quadrant front face of the model due to the action of random waves. Experimental set-up procedure analysis results and discussion are reported.
AuthorsV Sundar ; B V V Subba Rao
Date published2001
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Progress report on the AquaHabiStat deoxygenation system
AuthorsW J Browning Jr ; J P Davis ; W J Browning 3
Date published2003
AbstractThe AHS (AquaHabiStat) system is a patented purely mechanical BWT (ballast water treatment) system and removes DO (dissolved oxygen) from the ballast water as it is taken on board. The system has inbound ballast pumps which transfer water into a specially constructed steel tank. Here a vacuum is drawn on the water by a vacuum pump. A centrifugal pump them removes the water from the tank and moves it to the ships ballast hold. The marine life in the water suffocates in the ballast hold during the voyage. The water may then be discharged after 2-3 days. The water regains oxygen on discharge. The entire system may be run with a laptop PC.
AuthorsW J Browning Jr ; J P Davis ; W J Browning 3
Date published2003
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Strain behaviour at stable crack tip and effect of strength mis-match on crack growth resistance
AuthorsK Michiba ; H Hiramatsu ; H Hasegawa et al.
PublisherThe American Society of Mechanical Engineers - ASME
AbstractAn experimental study into the effects of strength mis-match on crack growth resistance and strain at the crack tip was carried out on two different steels (mild steel and 9Ni steel) in the homogeneous and heterogeneous conditions: compact tests to ASTM E813-1987 enabled determination of Crack Tip Opening Displacement (CTOD) crack resistance curves and strain behaviour during stable crack growth: stable crack growth was analysed by 3D FEM. The effect of constraint arising from strength mis-match on stable crack growth behaviour is discussed.
AuthorsDate publishedK Michiba ; H Hiramatsu ; H Hasegawa et al.
1996
PublisherThe American Society of Mechanical Engineers - ASME
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Study on onboard stochastic ship guidance system for heavy weather operation
AuthorsT Iseki ; D Terada
Date published2002
AbstractShipboard guidance systems for heavy weather operation need to be developed. New techniques are introduced into the Bayesian modelling procedure to estimate directional wave spectra based on ship motion data. In the proposed method the triple-valued function problem in following seas is strictly taken into account and the optimum solution is obtained from the stochastic viewpoint. Using the estimated directional wave spectrum it is shown that the future states of ship motions and longitudinal bending stresses can be evaluated based on the assumption of linear responses. To examine the reliability of the proposed method on board experiments are carried out. Comparisons between the results of the proposed method and onboard experiments show good agreement.
AuthorsT Iseki ; D Terada
Date published2002
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Successful drill cuttings reinjection (CRI) case history on a subsea template utilizing low cost natural oil based mud
AuthorsJ Reddoch ; C Taylor ; R Smith
Date published1995
AbstractDiscussion is presented of the drill cuttings reinjection (CRI) engineering and operating techniques utilized by British Gas and Apollo Services on the three year Tunisian Miskar project off the coast of Sfax Tunisia. Details are given of: well planning with information on template drilling as it relates to cuttings reinjections; injection well disposal design and planning including multiple well casing points for development drilling while producing; requirements for surface equipment personnel and commissioning; field results and data with adjustments for unplanned events; and economics of CRI and natural oil base versus synthetic oil mud. It is concluded that template drilling with CRI is a viable alternative on fast track programs in tough downhole drilling environments and can be extremely successful as long as proper engineering is performed and operations are conducted by experienced contractors.
AuthorsJ Reddoch ; C Taylor ; R Smith
Date published1995
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The effect of PWHT on the material properties and micro structure in Inconel 625 and Inconel 725 buttered joints
AuthorsVigdis Olden ; Egil Kvaale ; Arne Simensen et al.
Date published2003
AbstractThis paper describes investigations performed on as welded and post weld heat treated samples of AISI 8630 steel buttered with Inconel 625 and Inconel 725. The investigations were focused on the properties and microstructure in the partial mixed zone between the buttering and the steel before and after post weld heat treatment. The samples were heat treated for 4 hours 30 minutes at 640°C 665°C and 690°C and investigated with respect to mechanical properties and microstructure near the fusion line. A range of testing and analyses were performed. Additional investigations in TEM on samples from an actual joint post weld heat treated at 665°C were also performed.
AuthorsVigdis Olden ; Egil Kvaale ; Arne Simensen et al.
Date published2003
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The influence of the bow shape of FPSOs on drift forces and green water
AuthorsB Buchner
Date published1996
AbstractThe influence of the bow shape of floating production storage and offloading vessels (FPSOs) on drift forces and green water loading has been studied. The results of model tests and diffraction calculations are discussed for a traditional tanker bow a sharp alternative bow without a flare and a sharp alternative bow with a significant flare above the waterline. The mean wave and low- frequency drift forces seem to be smaller for the sharp bows than for the traditional bow. It is not clear whether the total mooring line loads for the sharp bows are lower because the wave frequency motions are larger. The relative motions around the sharp bows are larger than for the traditional bow resulting in more water on the deck. The impact pressures are also significantly higher. The discussed results suggest that it is not sensible to optimise FPSO bows on one aspect only.
AuthorsB Buchner
Date published1996
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The load-on-top systems for reducing oil pollution from Norwegian tanker experience and possible design improvements
AuthorsS Overaas ; E Solum
Date published1974
AbstractOperation of load-on-top systems for reducing oil pollution from Norwegian tankers in accordance with the requirements of the IMCO International Convention for the Prevention of Pollution from Ships 1973 was studied by detailed sampling and analysing of discharge waters and tank sludge from in-service vessels and by similar experiments on a working model tank system. The results are used to discuss - successful operation of LOT; improvements to current systems; and sytems layout on board and documentation. Guidelines for the design and operation of newbuildings considered
AuthorsS Overaas ; E Solum
Date published1974
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The performance of a hybrid Boussinesq model on wave runup and overtopping predictions for coastal structures
AuthorsB Weston ; A Borthwick ; P Taylor
Date published2005
AbstractSeveral numerical models have been developed for the prediction of wave runup and overtopping of coastal structures based on the non-linear shallow water (NLSW) equations. However these are limited solely to the simulation of long waves due to the equation set neglecting the effects of dispersion. To correct this the NLSW equations can be replaced by the Boussinesq equations which include dispersion effects. This extended set of equations can then be successfully applied to shrter waves. Now a hybrid numerical model BWAVE based on a conservative hyperbolic form of the Boussinesq equations and spliced with the NLSW equations that are conveniently embedded within this set of Boussinesq equations is presented. This work aims to demonstrate that when compared to predictions based on the NLSW equations alone hybrid models that include the effects of dispersion can give improved accuracy for wave rump measurements and overtopping volumes for breaking and non-breaking wave events in shallow water.
AuthorsB Weston ; A Borthwick ; P Taylor
Date published2005
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The revised STCW convention : A guide for the shipping industry on the 1995 amendments to the IMO International Convention on Standards of Training, Certification and Watchkeeping for Seafarers
AuthorsInternational Shipping Federation (ISF)
Shelf Location233c
AbstractThis guide has sections explaining why the STCW Convention was revised, an overview of the STCW package, technical details, explicit new responsibilities and implicit new obligations and how they will apply to shipping companies, uniform standards of competence, alternative methods of issuing certificates, and ensuring implementation of the revised Convention.
AuthorsPublisherInternational Shipping Federation (ISF)
International Shipping Federation (ISF)
Shelf LocationDate published233c
1995
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Upgrading of MARNET-technology by event controlled samplers for organic contaminants and automatic pump photometers for nutrient measurements
AuthorsK Herklotz ; S Schwarz ; H Nies
Date published2002
AbstractIn the North Sea and the Baltic Sea concentrations of nutrients and organic compounds are controlled by the inputs of different variable sources biogeochemical conversions sinks such as sedimentation or denitrification and advective exports. For nutrients and micropollutants continuous data with high temporal resolution are necessary to describe a complete annual cycle as well as short-term events reasonably. In the past chemical variables were measured either on single research campaigns or on regular monitoring cruises. These data sets limited on single periods of the year cannot detect short- or middle-term processes which could have considerable impact on the state and on the ecological effects of hydrographically high variable sea areas. Automatic nutrient analysers and event-controlled samplers for organic pollutants which are installed on sea-based stations are introduced as a more effective way to get insight into these processes. A system description is presented.
AuthorsK Herklotz ; S Schwarz ; H Nies
Date published2002