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SUMMARY:Dislocation motion and instability - Professor Jon Chapman\, Unive
 rsity of Oxford
DTSTART:20111111T140000Z
DTEND:20111111T153000Z
UID:TALK33468@talks.cam.ac.uk
CONTACT:Ms Helen Gardner
DESCRIPTION:The Peach-Kohler expression for the stress generated by a sing
 le (nonplanar) curvilinear dislocation is evaluated to calculate the dislo
 cation self stress. This is combined with a law of motion to give the self
 -induced motion of a general dislocation curve. A stability analysis of a 
 rectilinear\, uniformly translating dislocation is then performed. The dis
 location is found to be susceptible to a helical instability\, with the ma
 ximum growth rate occuring when the dislocation is almost\, but not exactl
 y\, pure screw.  The nonlinear evolution of the instability is determined\
 , and implications for slip band formation and non-Schmid behaviour in yie
 lding discussed.
LOCATION:Oatley Seminar Room\, Department of Engineering
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