Accession Number : ADA223420


Title :   Ice Forces on Flat, Vertical Indentors Pushed through Floating Ice Sheets


Descriptive Note : Special rept.


Corporate Author : COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH


Personal Author(s) : Nakazawa, Naoki ; Sodhi, Devinder S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a223420.pdf


Report Date : May 1990


Pagination or Media Count : 68


Abstract : Structures placed in an ice environment should be able to withstand the ice forces that are produced by the motion of a floating ice sheet. To observe the crushing failure of ice and to characterize the magnitude and nature of ice forces, an experimental study was conducted by pushing vertical, flat indentors through floating ice sheets made up of freshwater, columnar ice. Depending on the velocity of the indentor, ductile or brittle behavior of ice was observed. Microcracks and macrocracks were observed during the tests. The energy used to produce the maximum ice force was found to be approximately the same for different indentor velocities. The positions of the resultant forces were found to be in the center of the contact area. The area of the ice damaged by the first peak loading of the identor was about the same, even when the indentor velocities were different. Acoustic emission signals were measured during indentation experiments, and these were found to correlate with the ice force that produces strain and microcracking in the ice. Keywords: Ice mechanics; Cracking/fracturing; Coastal engineering; Offshore structures; Load distribution; Crushing; Effective pressure; Freshwater ice; Ice forces; Laboratory tests; Macrocracking; Microcracking.


Descriptors :   *CRACKING(FRACTURING) , *LOAD DISTRIBUTION , *ICE , LABORATORY TESTS , LOADS(FORCES) , CRACKS , STRAIN(MECHANICS) , FRESH WATER , BRITTLENESS , MODEL TESTS , SHEETS , PRESSURE , ACOUSTIC SIGNALS , DUCTILITY , COASTAL ENGINEERING , FAILURE(MECHANICS) , OFFSHORE STRUCTURES , ACOUSTIC EMISSIONS , FLOATING BODIES , CRUSHING , MECHANICAL PROPERTIES , MICROCRACKING , VELOCITY , PEAK VALUES


Subject Categories : Snow, Ice and Permafrost


Distribution Statement : APPROVED FOR PUBLIC RELEASE