BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Theory of Elasticity at the Nanoscale - Professor Bhushan Karihalo
 o\, Cardiff University
DTSTART:20091113T140000Z
DTEND:20091113T150000Z
UID:TALK20235@talks.cam.ac.uk
CONTACT:Ms Helen Gardner
DESCRIPTION:We have shown in a series of recent papers that the classical 
 theory of elasticity can be extended to the nanoscale by supplementing the
  equations of elasticity for the bulk\nmaterial with the generalized Young
 –Laplace equations of surface elasticity in order to capture the often u
 nusual mechanical and physical properties of nano-structured particulate a
 nd porous materials. This talk\, based on the review paper Advances in App
 lied Mechanics (42\, 2009\, 1-68)\, will describe how this has been done.\
 n  It will begin with a description of the generalized Young–Laplace equ
 ations. It will then generalize the classical Eshelby formalism to nano-in
 homogeneities\; the Eshelby tensor now depends on the size of the inhomoge
 neity and the location of the material point in it. Then the stress concen
 tration factor of a spherical nanovoid is calculated\, as well as the stra
 in fields in quantum dots (QDs) with multi-shell structures and in alloyed
  QDs induced by the mismatch in the lattice constants of the atomic specie
 s.\n  This will be followed by a generalization of the micromechanical fra
 mework for determining the effective elastic properties and effective coef
 ficients of thermal expansion of heterogeneous solids containing nano-inho
 mogeneities. It will be shown\, for example\, that the elastic constants o
 f nanochannel-array materials with a large surface area can be made to exc
 eed those of the nonporous matrices through pore surface modification or c
 oating. \n  Finally\, the scaling laws governing the properties of nano-st
 ructured materials are derived. The underlying cause of the size dependenc
 e of these properties at the nanoscale is the competition between surface 
 and bulk energies. These laws provide a yardstick for checking the accurac
 y of experimentally measured or numerically computed properties of nano-st
 ructured materials over a broad size range and can thus help replace repea
 ted and exhaustive testing by one or a few tests.
LOCATION:Oatley Seminar Room\, Department of Engineering
END:VEVENT
END:VCALENDAR