[PDF] Ice Structure Interaction Accounting For Fracture Of Ice eBook

Author : Mark Bradley Kavanagh
Publisher :
Page : pages
File Size : 18,81 MB
Release : 2018
Category :
ISBN :

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An important aspect of ice fracture that is yet to be fully resolved in determining the loads and pressures during an interaction with ice is the presence and growth of fractures. Practical applications include icebreakers ramming into ice pack or structures operating in ice-prone regions. Existing models often use a simplified view of ice mechanics, often based on only the elastic properties, which tend to overestimate the strength of the ice. It has long been known that ice exhibits time-dependent properties, including its strength. This is known from ship ramming experience as well as field and laboratory experiments. Accounting for these time-dependent aspects of ice behaviour would allow for a more analytical approach to interaction modelling and complement the empirical data that is used currently in design practice. The aim of this thesis is to provide a better understanding of ice fracture that occurs during an interaction. To better understand the viscoelastic properties of ice, an extensive review of the literature was performed. In particular, an in-depth review of linear elastic fracture mechanics was performed, as it it critical to the foundations of the viscoelastic fracture theory. To guide the development of a new viscoelastic fracture model, three sets of experiments were performed. The first was an indentation series, scaled down from similar field experiments, that displayed several fracture properties of ice. These properties were rate-dependent fracture, delayed fracture, and scale effects. The next two series, designed to study a single crack, used ice samples under 4- point bending. The first of these were constant loading rate test to further study the rate-dependent fracture properties of ice, resulting in ice that is weaker under faster loading in a decreasing power law relationship. The second of these applied constant loads just below the breaking point to show that ice undergoes delayed fracture. The data suggests a decreasing power law between applied load and time to failure for these samples. Building on previous works in viscoelastic fracture theory, and making use of the insights gained from the experiments, a new model has been developed to predict the fracture properties of ice. The model accounts for the delayed fracture of ice and provides insights into the time-dependent fracture properties of ice, as was seen in the laboratory and field experiments. The model, based on viscoelastic theory, was shown to reasonably model time to failure for ice beams under constant load, as well as the fracture strength of ice beams under different loading rates. The model, besides expanding the old theories to beam bending geometries, was also shown to work for compact tension specimens with a few minor changes.

Author : Ryszard Staroszczyk
Publisher : Springer
Page : 334 pages
File Size : 49,52 MB
Release : 2018-12-29
Category : Science
ISBN : 3030030385

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This book presents the concepts and tools of ice mechanics, together with examples of their application in the fields of glaciology, climate research and civil engineering in cold regions. It starts with an account of the most important physical properties of sea and polar ice treated as an anisotropic polycrystalline material, and reviews relevant field observations and experimental measurements. The book focuses on theoretical descriptions of the material behaviour of ice in different stress, deformation and deformation-rate regimes on spatial scales ranging from single ice crystals, those typical in civil engineering applications, up to scales of thousands of kilometres, characteristic of large, grounded polar ice caps in Antarctica and Greenland. In addition, it offers a range of numerical formulations based on either discrete (finite-element, finite-difference and smoothed particle hydrodynamics) methods or asymptotic expansion methods, which have been used by geophysicists, theoretical glaciologists and civil engineers to simulate the behaviour of ice in a number of problems of importance to glaciology and civil engineering, and discusses the results of these simulations. The book is intended for scientists, engineers and graduate students interested in mathematical and numerical modelling of a wide variety of geophysical and civil engineering problems involving natural ice.

Author : Wade H. Shafer
Publisher : Springer Science & Business Media
Page : 430 pages
File Size : 30,74 MB
Release : 2012-12-06
Category : Science
ISBN : 1461573947

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Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Oata Analysis and Synthesis (CINOAS) * at Purdue. University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 33 (thesis year 1988) a total of 13,273 theses titles from 23 Canadian and 1 85 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 33 reports theses submitted in 1988, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

Author : Ian Jordaan
Publisher : Cambridge University Press
Page : 245 pages
File Size : 49,19 MB
Release : 2023-02-28
Category : Science
ISBN : 1108481604

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Featuring real-world examples and practical methodology, this rigorous text combines mechanical theory with design and modelling.

Author : Wilford Frank Weeks
Publisher :
Page : 92 pages
File Size : 11,7 MB
Release : 1969
Category : Fracture mechanics
ISBN :

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The increased activity in cold regions has made a thorough understanding of fracture in lake and sea ice quite desirable, inasmuch as this information has application to a number of problems of geophysical as well as engineering importance. This survey starts with a discussion of the structure of ice I and the macro- and microstructure of sea and lake ice as well as their chemistry and phase relations. Recent work on the direct observation of dislocations as well as the formation of cracks in ice is summarized. Formal ice-brine-air models for analyzing variations in ice strength are also reviewed. The results of the different types of tests are discussed and compared (compressive, indentation, direct and ring-tension, small beam flexure and in situ cantilevers and simple beams, shear, and impact). Scale effects are considered as well as the rapid strength deterioration experienced by ice sheets in the spring. Finally, a number of recommendations are made concerning future research in this field. (Author).

Author : Thomas R. Mackey
Publisher :
Page : 144 pages
File Size : 35,27 MB
Release : 2006
Category : Fracture mechanics
ISBN : 9780494304822

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*Please refer to dissertation for table.