The flexural behaviour of ice from in situ cantilever beam tests
The cantilever beam test has been used very extensively in both the field and laboratory to investigate the flexural strength and strain modulus of sea ice. Shortcomings in the test are generally recognized, hence these measurements are used only as index values. One problem with flexural tests is t...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
1978
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| Subjects: | |
| Online Access: | https://nrc-publications.canada.ca/eng/view/ft/?id=84e2fbd5-ffed-4eff-8431-9ff7fdb5e359 https://nrc-publications.canada.ca/eng/view/object/?id=84e2fbd5-ffed-4eff-8431-9ff7fdb5e359 https://nrc-publications.canada.ca/fra/voir/objet/?id=84e2fbd5-ffed-4eff-8431-9ff7fdb5e359 |
| Summary: | The cantilever beam test has been used very extensively in both the field and laboratory to investigate the flexural strength and strain modulus of sea ice. Shortcomings in the test are generally recognized, hence these measurements are used only as index values. One problem with flexural tests is that some prior knowledge about the material properties is required before they can be analyzed. The first part of this paper considers the elastic theory of a beam on an elastic foundation. Various factors that affect the interpretation of cantilever beam tests are examined, i.e., beam geometry, elastic foundation effect, and nonhomogeneity of elastic modulus through beam thickness. The second part of the paper presents results from in situ cantilever beam tests in Isfjorden, Spitsbergen, conducted during full scale trials with the offshore supply vessel M.V. "Werdertor" by a German group of investigators under the management of the Hamburgische Schiffbau-Versuchsanstalt. Field tests were carried out on 0.4 m thick sea ice with beam lengths up to 12 m. Load and beam deflections at up to three points were measured versus time. From these measurements strength and modulus index values were determined and the behaviour of a long cantilever beam on a foundation was confirmed. Frankenstein's approach of relating strength and strain modulus to the brine volume of saline ice was found to be quite applicable. L'essai de la poutre en porte-à-faux a été utilisé massivement autant en laboratoire que sur place pour étudier la résistance à la flexion et la déformation de la glace marine. Les lacunes de l'essai étant généralement décelées, ces mesures sont utilisées comme valeurs de repère. La première partie de l'article traite de la flexibilité d'une poutre sur une fondation élastique. Divers facteurs pouvant affecter l'interprétation des essais des poutres en porte-à- faux sont examinés, tels que la géométrie de la poutre, l'effet de la fondation élastique et la diversité des coefficients d'élasticité dans l'épaisseur de la ... |
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