Day 3 Wed, July 30, 2014最新文献

{"title":"Bond Enhancement in Curved Sandwich Shells","authors":"P. Marshall, Vul Thang, Nicholas A. Brake, P. Corder","doi":"10.5957/icetech-2014-111","DOIUrl":"https://doi.org/10.5957/icetech-2014-111","url":null,"abstract":"As follow-up to recent papers by Marshall et al. (2010, 2012), research on steel-concrete-steel (SCS) sandwich shells for Arctic offshore structures continues at two universities. National University of Singapore is testing heavy transverse reinforcement which ties the outer steel plates together. Lamar University in Texas originally studied the composite ice wall concept in the late 1980s, and is now testing surface treatment with a size-tiered gradation of mini-studs, macro fibers (steel) and micro fibers (synthetic), intended to develop the full bulk properties of the Fiber Reinforced Concrete (FRC) core in radial tension and punching shear. Using ISO’s design non-hydrostatic partial span loading on the Singapore Cone, radial bond stress at the inner steel plate is low and deemed attainable for both the stud enhanced bonding surface and the bulk concrete core. The steel shell serves as prefabricated permanent formwork, and the arched vaults resist external ice loading mainly by compression, provided the sandwich does not disintegrate in an unstable fashion.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134162456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavior of Ice Covers Under Moving Loads – the Driving Mechanism","authors":"M. Lanteigne, Gary Van Der Vinne","doi":"10.5957/icetech-2014-175","DOIUrl":"https://doi.org/10.5957/icetech-2014-175","url":null,"abstract":"Measurements of the response of a floating ice cover to a loaded vehicle travelling at various speeds indicate that the “deflection bowl” created under the weight of the vehicle behaves like a vessel which is carrying the vehicle over the water surface. Because the ice cover is flexible, the bowl changes shape as the forces acting on it change with speed. Results show that: 1) as vehicle speed increases towards “critical speed” the depth of the bowl increases from the effect of the Bernoulli principle; 2) the depth of the bowl diminishes above critical speed from dynamic lift; 3) critical speed is sensitive to water depth – which is predicted by the Bernoulli principle.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115246312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method for Characterizing Uncertainty in Tactical Sea Ice Drift Forecasting","authors":"J. Blunt, D. Mitchell, A. Younan","doi":"10.5957/icetech-2014-115","DOIUrl":"https://doi.org/10.5957/icetech-2014-115","url":null,"abstract":"Hydrocarbon exploration in the high-Arctic offshore region may require enhanced station keeping capability in ice due to a limited open water summer season and/or the potential for temporary pack ice intrusions during a nominal open water season. Ice management systems have been employed as a means to improve station keeping ability in the presence of drifting sea ice, but accurate ice drift forecasting is central to improving the reliability of any ice management system. A rigorous approach to both (1) quantifying and (2) communicating the uncertainty associated with sea ice drift forecasting is proposed in this paper.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133531579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Measurement of Shallow Ocean Currents Beneath Deformed Mobile Sea Ice Using Upward Looking Sonar Instruments","authors":"T. Mudge, D. Fissel, K. Borg, N. Milutinovic, E. Ross","doi":"10.5957/icetech-2014-157","DOIUrl":"https://doi.org/10.5957/icetech-2014-157","url":null,"abstract":"The under ice ocean currents are critical in the understanding of the boundary layer between the sea ice and the ocean, involving determination of the drag forces that sea-ice exerts on the upper water column and the related turbulence and mixing levels. A semi-automated algorithm has been developed, which accounts for the changes in sea ice drafts, to determine the nearest surface ocean current measurement level. Using long-term measurements from upward looking sonar datasets in the Chukchi and Beaufort Seas, the algorithm and its extensions to all current bins is investigated.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123372580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Short History of Ice Model Tests in Finland","authors":"G. Wilkman","doi":"10.5957/icetech-2014-164","DOIUrl":"https://doi.org/10.5957/icetech-2014-164","url":null,"abstract":"Ice navigation has been practiced on regular basis some 120 years and testing of ships in a model laboratory close to 60 years. In Finland the first laboratory was commenced only 45 years ago. Open water facilities have it much less complicated as they only need the water. In ice modeling the cornerstone is how to model ice, which in fact is just hard water. A lot of different materials have been used for ice modeling. Normally when you get some of the properties right, some go wrong. The ice modeling materials used during the short history goes from naturally grown saline ice through different chemicals mixed with water, wax and plastics towards ice that is actually built or constructed or the natural growth has been disturbed by using different methods to control the density. This paper discusses the development of model testing, its different features and how the development has taken place in Finland.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122701347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Extreme Ice Features in the Canadian Arctic","authors":"I. Zakharov, P. Bobby, S. Warren, D. Power","doi":"10.5957/icetech-2014-102","DOIUrl":"https://doi.org/10.5957/icetech-2014-102","url":null,"abstract":"Research on automatic detecting, tracking and characterizing extreme ice features in the Arctic is based on analyzing and processing satellite synthetic aperture radar (SAR) and optical images. Algorithms to identify ridges from very high-resolution optical data have an accuracy of 86.4% when compared to manual extraction and ridge height has been estimated from shadow. SAR signatures of various ice features have been analyzed and the results indicate that it is possible to identify rubble fields from other ice types.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117325177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Field-scale High Pressure Zones during Non-simultaneous Failure of Thin First-year Sea Ice","authors":"R. Taylor, M. Richard","doi":"10.5957/icetech-2014-161","DOIUrl":"https://doi.org/10.5957/icetech-2014-161","url":null,"abstract":"For temperate ice regions, the guidance provided by current design codes regarding ice load estimation for thin ice is unclear, particularly for local pressure estimation. During the non-simultaneous failure of ice under compression, spalling fracture localizes contact into high pressure zones (hpzs), through which the majority of loads are transmitted. Much of our present understanding of hpzs comes from inferences made from the analysis of pressure panel data collected during medium-scale field tests or full-scale measurements on ships or structures. During medium-scale field indentation tests conducted by the Japan Ocean Industries Association (JOIA) from 1996-2000, tactile pressure sensors were also deployed. The JOIA dataset provide detailed information about pressure distributions at a sufficiently high resolution so as to allow for the identification and tracking of individual hpzs throughout an interaction. Given their importance in the transmission of loads during an ice-structure interaction, understanding the birth, evolution and death of individual hpzs is seen as being an important direction both for guiding fundamental studies of ice mechanics and also for guiding the development of new ice load models. Recent analysis of these tactile sensor data has led to the development of an empirical hpz-based model which can be applied to model local and global pressures for thin ice conditions (Taylor and Richard, 2014). From this analysis, new insights into the nature of hpzs for thin first year sea ice during non-simultaneous failure have resulted. In the present paper, an overview is provided of analysis techniques used to extract information about individual hpzs from the tactile sensor dataset, as well as the characteristics of these hpzs. Aspects discussed include spatial and temporal characteristics of high pressure zones, as well as pressure and geometric attributes. While observations of the shape of spatial distributions and total contact area covered by hpzs are consistent with previous observations (line-type distributions with total contact area on the order of 10% of the nominal interaction area), these results indicate that individual hpzs are smaller and more densely distributed than indicated by previous analyses based solely on pressure panel data. The implications of this finding in terms of scale effects and ice load modeling are discussed.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125298970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Experimental Data and Quantifying Influence of Dimensionless Material Properties, Velocity and Aspect Ratio on Ice-induced Forces on Vertical Structures","authors":"A. Arunachalam","doi":"10.5957/icetech-2014-155","DOIUrl":"https://doi.org/10.5957/icetech-2014-155","url":null,"abstract":"In this paper, the quantitative influence of aspect ratio (B/h), and dimensionless velocity or thickness Froude number [TFN = u/√(gh)] on dimensionless ice-induced pressures (pe/ρiu2) is briefly reviewed and discussed. Since material properties of ice (E, σf, K1c) have not been reported for many data-sets, a strategy for generating appropriate material properties for ice is proposed. Two dimensionless terms for material properties of ice, {(E/σf)×[K1c/(σf√h)]} and {[K1c/(σfu)]×√[E/(ρih)]} were identified and their influence on pe/ρiu2 is discussed. It was found that (1) pe/ρiu2 on rigid vertical structures decreases with (a) increasing B/h at a rate of about 0.42, when u/√(gh) and {[K1c/(σfu)]×√[E/(ρih)]} remain constant; (b) pe/ρiu2 decreases with increasing u/√(gh) at a rate of about 1.80 when u/√(gh) is < about 6.0×10-3and at a rate of about 1.93 when u/√(gh) is > about 6.0×10-3 when B/h and {[K1c/(σfu)]×√[E/(ρih)]} remain constant. (2) Preliminary analyses of the datasets shows that pe/ρiu2 decreases with increasing {(E/σf)× [K1c/(σf√h)]} at a rate of 0.335 and 0.469 and that pe/ρiu2 decreases with increasing {[K1c/(σfu)]×√[E/(ρih)]} at a rate of 0.729 and 0.808. (3) It was also found that shapes of structures do not influence dimensionless ice-induced pressures on structures.","PeriodicalId":176359,"journal":{"name":"Day 3 Wed, July 30, 2014","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115214834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}