Cracks in ice and their role in brittle compressive failure

60 mins,  111.39 MB,  MP3  44100 Hz,  253.47 kbits/sec
Share this media item:
Embed this media item:


About this item
Image inherited from collection
Description: Schulson, E (Dartmouth College, Dartmouth College)
Thursday 7th December 2017 - 11:30 to 12:30
 
Created: 2017-12-08 17:38
Collection: Mathematics of sea ice phenomena
Publisher: Isaac Newton Institute
Copyright: Schulson, E
Language: eng (English)
Distribution: World     (downloadable)
Explicit content: No
Aspect Ratio: 16:9
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: Cracks--new and old, short and long-- are ubiquitous features within the arctic sea ice cover. How they form and the role they play in mechanical behavior are important questions in ice mechanics. In this presentation, emphasis will be placed on brittle compressive failure. There, cracks preferentially oriented with respect to the applied stress state can slide intermittently across opposing surfaces in contact, activating in the process deformation mechanisms that can account for a number of observations/characteristics of brittle compressive failure on scales small and large. One such scale-independent mechanism is the wing-crack cum comb-crack mechanism: it can account for the axial splitting and shear faulting modes of terminal failure, conjugate faulting, brittle compressive strength and, upon consideration of crack-tip creep, the transition from brittle to ductile behavior. Application of confining stress above a critical level, set solely by the coefficient of kinetic friction, suppresses frictional sliding and activates, given a sufficiently high strain rate and triaxial confinement, a brittle-like mode of plastic failure governed by the different mechanism of adiabatic heating and dynamic recrystallization. These mechanisms will be described and questions arising addressed.
Available Formats
Format Quality Bitrate Size
MPEG-4 Video 640x360    1.96 Mbits/sec 886.17 MB View Download
WebM 640x360    699.43 kbits/sec 307.37 MB View Download
iPod Video 480x270    528.91 kbits/sec 232.43 MB View Download
MP3 * 44100 Hz 253.47 kbits/sec 111.39 MB Listen Download
Auto (Allows browser to choose a format it supports)