BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:Engineering - Mechanics and Materials Seminar Seri
 es
SUMMARY:Mechanics of Architected Materials Across Length a
 nd Time Scales - Prof Carlos M Portela\, School of
  Engineering\, MIT
DTSTART;TZID=Europe/London:20220225T140000
DTEND;TZID=Europe/London:20220225T150000
UID:TALK169727AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/169727
DESCRIPTION:Ferroelectric ceramics exhibit a spontaneous elect
 ric polarization that can be reversed under the ap
 plication of an electrical or mechanical loading. 
 The macroscopic features of polarization switching
  derive\, at the mesoscale\, from the nucleation a
 nd growth of domains of constant polarization (the
 se domains correspond to the different variants of
  the crystallographic phase).  Simulations of the 
 evolution of polarization domains are based on dif
 fuse-interface models (also called phase-field mod
 els) where the electro-mechanical fields evolve st
 eeply but continuously across domain walls. Existi
 ng  diffuse-interface models are based on the Alle
 n-Cahn equation which assumes\, unlike experimenta
 l evidence\, a linear relation between the velocit
 y of domain walls and their conjugate driving forc
 e. Therefore\, while the Allen-Cahn model provides
  appropriate modelling of polarization switching i
 n the quasistatic regime\, it fails to capture rat
 e effects involved in fast-switching experiments. 
 In this work\, we develop an alternative phase-fie
 ld formulation that accounts for the non-linear ki
 netics of domain walls and discuss its possibiliti
 es for modeling the step load response of ferroele
 ctrics as well as the effects of electrical loadin
 g rate.
LOCATION:Zoom Meeting ID: 898 3752 1667
CONTACT:
END:VEVENT
END:VCALENDAR