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CATEGORIES:Isaac Newton Institute Seminar Series
SUMMARY:Micromechanics of sea ice frictional slip from tes
t basin scale experiments - Peter Sammonds (Univer
sity College London)
DTSTART;TZID=Europe/London:20171207T100000
DTEND;TZID=Europe/London:20171207T110000
UID:TALK96331AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/96331
DESCRIPTION:Co-authors: Daniel Hatton and Daniel Feltham
We have performed high-resolution d
ouble-direct shear friction experiments on saline
ice floes in the HSVA environmental test basin. Th
e frictional motion was predominantly stick-slip.&
nbsp\; Shear stresses\, normal stresses\, local st
rains and slip displacement were measured along th
e sliding faults\, and acoustic emissions were mon
itored. High resolution measurements during a sing
le stick- slip cycle at several positions along th
e fault allowed us to identify two phases of frict
ional slip: a nucleation phase\, where a nucleatio
n zone begins to slip before the rest of the fault
\, and a propagation phase when the entire fault i
s slipping. We employed a constitutive relation fo
r frictional slip derived from the physics of aspe
rity-asperity contact. We find our experimental da
ta conform reasonably with this frictional law onc
e slip weakening is introduced. \; We deduce t
he interfacial faults failed in the stick-slip cyc
le through the process of brittle failure of asper
ities in shear\, and at higher velocities\, fricti
onal heating\, localized surface melting and hydro
dynamic lubrication.
LOCATION:Seminar Room 1\, Newton Institute
CONTACT:INI IT
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