Mechanics of Nanocrystalline Materials: From Discrete to Continuum

18th IUTAM Summer School on “Mechanics of Nanocrystalline Materials: From Discrete to Continuum”

September 10, 2012 — September 14, 2012

at

 International Centre for Mechanical Sciences (CISM), Udine , ITALY
 

http://www.cism.it/courses/C1210/

Coordinators:

• David L. McDowell
  (Georgia Tech, Atlanta, GA, USA)
• Mohammed Cherkaoui
  (Georgia Tech, Atlanta, GA, USA)

Since their discovery in the early 1980s, Nanocrystalline (NC)
materials have been the subject of great attention for they revealed
unexpected fundamental phenomena, such as the breakdown of the
Hall-Petch law, and suggested the possibility of reaching the
ever-so-challenging large-ductility/high-yield stress compromise.
Although the problem of describing the behavior of NC materials is still
challenging, numerous fundamental, computational, and technological
advances have been accomplished since then.
The mechanical behavior of NC materials has been subject to numerous
investigations, most of which are focused on the role of interfaces
(grain boundaries and triple junctions) and aimed at identifying the
mechanisms responsible for the breakdown of the Hall-Petch relation.
Within this context, the mechanical behavior of NC relies on a generic
idea in which grain boundaries serve as softening structural elements
providing the effective action of the deformation mechanisms in NC.
Therefore any modeling attempt toward the behavior of NC faces the
problem of identification of the softening deformation mechanisms
inherent in grain boundaries as well as the description of their
competition with conventional lattice dislocation motion.
In the context of NC, this course aims at discussing a complete and
rigorous state-of-the-art analysis of the modeling of the mechanical
behavior of NC materials. Among other key topics the material focuses on
the novel techniques used to predict the mechanical behavior of this
category of nanostructured materials. Particular attention is given to
recent theoretical and computational frameworks combining atomistic and
continuum approaches. Also, the most relevant deformation mechanisms
governing the response of NC materials are addressed and discussed in
correlation with available experimental data.
The lecturers will present novel models describing plastic deformation
processes occurring in NC materials, including grain boundary
dislocation emission and grain boundary sliding. They will cover scale
transitions from atomistic to continuum, and will show how to construct
and use a molecular dynamics code for practical use in the modeling of
NC materials, in addition to atomistic to continuum modeling schemes.
The course will cover a wide spectrum of materials, including: new
modeling techniques and their potential applications and possible
extensions, such as molecular dynamics, strain gradient based finite
element simulations, and novel micromechanical schemes describing
plastic deformation processes occurring in NC materials including grain
boundary dislocation emission.
The course is addressed to researchers, including graduate students who
are either entering these fields for the first time or actively
conducting research in this area and intending to extend their knowledge
of nanostructured materials.
KEYWORDS
: Nanocrystalline Materials,
Deformation Mechanisms, Plastic Deformation, Multiscale Modelling,
Heterogeneous Metallic, Materials.