BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Virtual MEchanics GAthering -MEGA- Seminar: Talk 1 - A Kirchhoff-l
 ike theory for the mechanics of magnetic rods\; Talk 2- Magneto-active ela
 stic shells with tunable buckling strength
DTSTART:20201126T161500
DTEND:20201126T173000
DTSTAMP:20260510T000034Z
UID:74c656cf87ae3785a58b744b18a60898e0dce3c467e8b6af332e4c4e
CATEGORIES:Conferences - Seminars
DESCRIPTION:Tomohiko Sano & Dong Yan (fleXLab\, EPFL)\nTalk 1: A Kirchhoff
 -like theory for the mechanics of magnetic rods\, by Tomohiko Sano (fleXL
 ab\, EPFL)\nMagneto-rheological elastomers (MREs) are functional materials
  that can undergo deformations when subject to external magnetic fields. M
 REs consist of hard magnetic particles dispersed into a nonmagnetic elasto
 meric (soft) matrix. There have been recent advances in the theoretical de
 scription of MREs using the framework of (3D) continuum mechanics. Reduced
 -order structural theories have also been developed for magnetic linear be
 ams and elastica\, based on the planar (2D) deformation of the centerline.
  In this talk\, we derive an effective theory for rods made of MRE undergo
 ing 3D geometrically nonlinear deformations. Our theory is based on the pr
 ocedure of dimensional reduction of the 3D magneto-elastic energy function
 al of the MRE into a 1D (centerline and Kirchhoff-like) description\, whic
 h encompasses the previous 2D theories under appropriate limits. We demons
 trate the accuracy of our theory by performing precision-model experiments
  to explore a set of specific problems involving the buckling behavior of 
 MRE rods. These experiments are also used to test the range of validity of
  our theory.\n\nBio Tomohiko Sano is a post-doc at the Flexible Structure
 s Laboratory at EPFL. He completed his bachelor’s and Ph.D. courses at t
 he Graduate School of Science\, Kyoto University\, Japan. After he got a P
 h.D. in 2016\, he worked as a post-doctoral researcher at Ritsumeikan Univ
 ersity\, near Kyoto\, Japan\, from 2016 to 2019. His research interests ar
 e mechanical functionalities in structures and geometry.\n\nTalk 2: Magnet
 o-active elastic shells with tunable buckling strength\, Dong Yan (fleXLa
 b\, EPFL)\nIt has long been recognized that the buckling of shell structur
 es is highly sensitive to material or geometric imperfections\, leading to
  observed critical loads that are significantly lower than classic predict
 ions. In this class of problems\, the knockdown factor is defined as the r
 atio between the experimentally measured critical load and the classic the
 oretical prediction. This knockdown is typically regarded as an intrinsic 
 property of the structure since the type and distribution of defects are e
 ncoded into the shell during fabrication. Here\, we demonstrate the abilit
 y to actively tune the knockdown factor of pressurized spherical shells. W
 e fabricate our spherical shells with a magneto-rheological elastomer (MRE
 ) using a coating technique. The shells are first magnetized and then load
 ed by pressure under a uniform magnetic field. We find that\, by adjusting
  the strength and polarity of the field\, the knockdown factor of the magn
 etically active shells can be increased or decreased up to a maximum chang
 e of 30%. As such\, we can externally tune their intrinsic buckling streng
 th\, on-demand. An axisymmetric shell model is used to rationalize the exp
 erimental results on how the magnetic field interacts with the buckling of
  imperfect shells.\n\nBio Dong Yan got his Ph.D. in Mechanical Engineerin
 g at Beijing Institute of Technology\, China\, in 2017. Then he joined the
  Flexible Structures Laboratory (the fleXLab) at EPFL as a post-doc\, work
 ing with Prof. Pedro Reis on shell buckling and magneto-elastic structures
 .\n 
LOCATION:Zoom: epfl.zoom.us/s/98393329833 Room Passcode: 349948 http://epf
 l.zoom.us/s/98393329833
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR