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SUMMARY:Correlation of local ice forces across the width of a structure du
 ring ice-structure interaction - Devinder Sodhi (U.S. Army Research Labora
 tory)
DTSTART:20171108T113000Z
DTEND:20171108T123000Z
UID:TALK94696@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:The concepts presented in this paper pertain to an ice floe mo
 ving against a wide structure\, having an aspect ratio greater than 10\, a
 nd are based on results of small-scale and medium-scale indentation tests 
 as well as published data of measured ice forces on full-scale structures.
  <br><br>Data from indentation tests with tactile sensors at the ice-struc
 ture interface reveal that:   (a) interactions at low ice speed produce du
 ctile deformation of ice\, creating a slowly expanding contact area until 
 it covers 100% of the nominal contact area\, and (b) interactions at inter
 mediate and high ice speeds produce brittle failure of ice\, resulting in 
 the actual contact area to be less than the nominal contact area. <br><br>
 During interactions at intermediate and high speeds\, brittle failure of i
 ce creates uneven surface at the ice-structure interface\, creating asperi
 ties at the ice front. When these asperities advance towards the structure
 \, they generate contacts at a few isolated spots. During an ice-structure
  interaction\, these contact areas expand under contact pressure with time
 \, causing local ice forces to be generated at the ice-structure interface
 . The summation of all local forces at an instant in time is the global ic
 e force.  <br><span><br>The results of indentation tests with a segmented 
 indentor and tactile sensor reveal a decrease in correlation of local ice 
 forces across the width of a structure with increasing ice speed. This res
 ults in a decrease in variance of global effective pressure while the aver
 age global effective pressure remains in the range of local average effect
 ive pressure. These two effects are well supported by experimental results
 . The correlation of local ice forces is quantified by a correlation-lengt
 h parameter\, which decreases with increasing ice speed as per experimenta
 l data. These concepts of ice crushing process have been incorporated in a
  theoretical ice-structure-interaction model.&nbsp\;</span>
LOCATION:Seminar Room 1\, Newton Institute
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