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Comfort G.,BMT Fleet Technology | Croasdale K.,KRCA Ltd.
International Conference and Exhibition on Performance of Ships and Structures in Ice 2012, ICETECH 2012 | Year: 2012

The ice load predictors in present codes tend to be empirical. The empirical relationships are heavily influenced by data from relatively small areas and thickness ranges. One uncertainty in applying the predictors is related to the effect of different contact zone geometries, as these variations tend to get "smeared" over the whole contact zone in the present empirical predictors. An approach (termed the Two-Zone Model) was developed to investigate the effect of various contact zone geometries on global loads and pressures. The contact zone was divided into two independent zones based on their proximity to a free edge. Lower pressures were prescribed for the Outer Zone on the presumption that these would be governed by spalling and flaking of the ice. Various approaches were explored to develop the Two-Zone Model to provide insights and identify sensitivities; and two Cases were used for sample analyses. The Two-Zone model was run for three scenarios producing significantly different contact zone geometries. Of course, the results are sensitive to the assumptions made regarding the pressures within, and the extents of, the Inner and Outer Zones. The work serves to highlight some of the uncertainties involved in estimating ice loads associated with severe ice-structure events. It is hoped that it will help to point a way forward for taking more direct account of the variations in contact zone geometries created by major ice-structure interaction scenarios. Further work in the form of both modelling improvements and large-scale measurements, would be beneficial to quantify the key inputs and relationships for the Two-Zone model. In fact, exercising this type of model helps to highlight the uncertainties and emphasizes the need for full-scale data at larger areas than measured to date and over a range of aspect ratios. Copyright ©2012 ICETECH 12. All rights reserved. Source


Dinovitzer A.,BMT Fleet Technology
Engineering and Technology | Year: 2010

Welding has become a high-tech process that needs sophisticated procedures, strong technical back-up and a new way of thinking. The common weld is a much maligned beast. Despite the layman's preconception that welding is a rough, unsubtle industrial process, it is actually a complex procedure with many parameters affecting the result. Source


Judson B.,BMT Fleet Technology
International Conference and Exhibition on Performance of Ships and Structures in Ice 2010, ICETECH 2010 | Year: 2010

Significant research on Arctic sea ice trends and the potential for resource development have been well documented and illustrated as drivers for changes to Arctic shipping traffic patterns. There is a strong awareness of the potential risks to the environment such as an oil spill in ice as well as impacts on traditional human activity. Similarly, there is awareness that there will be a demand for increased navigation services such as aids to navigation, charting and emergency response capacity. However, many questions remain about what impact sea ice trends and resource development have had on shipping and accidents. To date, the Arctic Marine Shipping Assessment (AMSA) project has provided a snapshot of Arctic shipping traffic patterns and activity for the year 2004 and suggests a further research opportunity exists to conduct a trend analysis of shipping activity. The AMSA report suggests that "As marine activity continues to expand in the Arctic, statistical trends indicate that the potential risk of vessel mishaps and marine pollution incidents also increases" (Arctic Council, 2009). However, this is not necessarily the case where risks are managed. Accident trends in the Canadian Arctic suggest that safety management, vessel design and navigation experience have had positive impacts and one must look more closely at specific areas of operation, vessel types and activity to identify opportunities to improve risk management including both prevention and response. So the question remains "What can we learn from recent trends in vessel traffic and accident rates to better understand potential navigation impacts in the future?" Using the AMSA Shipping Database (Arctic Council, 2009) and a spatial trend analysis of Canadian Arctic shipping traffic and vessel accident rates covering the period 1987 to 2008, this paper will report on preliminary findings, show where accident rates are increasing and decreasing, provide traffic trends for each Shipping Safety Control Zone, help to dispel a few myths, and possibly confirm other rumours. Copyright ©2010 ICETECH 10. All rights reserved. Source


Judson B.,BMT Fleet Technology
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2010

Significant research on Arctic sea ice trends and the potential for resource development have been well documented and illustrated as drivers for changes to Arctic shipping traffic patterns. There is a strong awareness of the potential risks to the environment such as an oil spill in ice as well as impacts on traditional human activity. Similarly, there is awareness that there will be a demand for increased navigation services such as aids to navigation, charting and emergency response capacity. However, many questions remain about what impact sea ice trends and resource development have had on shipping and accidents. To date, the Arctic Marine Shipping Assessment (AMSA) project has provided a snapshot of Arctic shipping traffic patterns and activity for the year 2004 and suggests a further research opportunity exists to conduct a trend analysis of shipping activity. The AMSA report suggests that "As marine activity continues to expand in the Arctic, statistical trends indicate that the potential risk of vessel mishaps and marine pollution incidents also increases" (Arctic Council, 2009). However, this is not necessarily the case where risks are managed. Accident trends in the Canadian Arctic suggest that safety management, vessel design and navigation experience have had positive impacts and one must look more closely at specific areas of operation, vessel types and activity to identify opportunities to improve risk management including both prevention and response. So the question remains "What can we learn from recent trends in vessel traffic and accident rates to better understand potential navigation impacts in the future?" Using the AMSA Shipping Database (Arctic Council, 2009) and a spatial trend analysis of Canadian Arctic shipping traffic and vessel accident rates covering the period 1987 to 2008, this paper will report on preliminary findings, show where accident rates are increasing and decreasing, provide traffic trends for each Shipping Safety Control Zone, help to dispel a few myths, and possibly confirm other rumours. Copyright © 2010 by The International Society of Offshore and Polar Engineers (ISOPE). Source


Fredj A.,BMT Fleet Technology | Dinovitzer A.,BMT Fleet Technology
Proceedings of the Biennial International Pipeline Conference, IPC | Year: 2010

Understanding the effect of soil-pipeline interactions in the event of large ground movement is an important consideration for pipeline designer. Both experimental investigation and computational analyses play significant roles in this research. As part of this effort, a framework incorporating continuum soil mechanics and advanced finite element approach (i.e., ALE and SPH method) for modeling soil pipe interaction is developed. The overall objective is to develop, validate and apply 3D continuum modeling technique to assess the performance of pipeline system subjected to large soil displacement. The numerical models than may be used to predict the wrinkle formation and post formation behavior of the pipeline considering the effect of the soil confinement, and develop a comprehensive wrinkle integrity assessment process. This is the second paper (Part II) in a series of two papers. In the first paper a three-dimensional Continuum models using MM-ALE (Multi-material Arbitrary Eulerian Lagrangian) and SPH (smooth particle hydrodynamics) approaches are developed and run using LS-DYNA. The results are compared with published experimental data of large-scale test to verify the numerical analysis methods. In this paper (Part II) the effects of soil restraint on the response of the pipe/soil systems (e.g., pipeline Wrinkle and buckle, strain demand) are discussed. Copyright © 2010 by ASME. Source

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