Skip to Content.
Sympa Menu

fizinfo - [Fizinfo] Noël Challamel előadása a BME-n

fizinfo AT


List archive

[Fizinfo] Noël Challamel előadása a BME-n

Chronological Thread 
  • From: Károlyi György <karolyi AT>
  • To: undisclosed-recipients: ;
  • Subject: [Fizinfo] Noël Challamel előadása a BME-n
  • Date: Mon, 25 Apr 2016 15:34:11 +0200


Noël Challamel (Université de Bretagne Sud, Lorient,France):
Quasicontinuum: an intermediate state between discrete and continuous media
c. előadására

Időpont: 2016. május 18. szerda 10:30
Helyszín: Budapesti Műszaki és Gazdaságtudományi Egyetem
Műegyetem rkp. 3.
K épület 3. emelet 354/a terem.

Az előadás tartalma:

In this seminar, we will question the possibility to investigate discrete
media such as lattices using quasicontinuum mechanics. Discrete media
considered in this study are typically periodically microstructured media
such as atomistic media, lattices, granular material or even truss structures
for large scale applications. Quasicontinua may be defined as continuous
media which behave like discrete media, but with a continuous formulation.
Mathematically, the question is equivalent to approximate difference
equations within some equivalent differential or partial differential
equations, including possibly higher-order terms. From an engineering point
of view, it is generally much simpler to investigate the behaviour of these
discrete or microstructured media using continuum tools. The seminar will be
mainly oriented towards the characterization of quasicontinua for structural
mechanics applications.

Quasicontinua investigated in this study are of nonlocal or gradient types.
It is shown that discrete strings (or lattice string) as already considered
by Lagrange during the XVIIIth century may be revisited in the light of
modern mechanics theories such as nonlocal mechanics. During the 19th
century, Piola built some nonlocal-type or gradient-type media from discrete
microscale interactions. Hencky-bar system, developed at the beginning of the
XXth century can be considered as the paradigmatic bending lattice with
inherent length scale. The nonlocal or gradient-type laws which emerge from a
continualization procedure of such structural lattice are used for analysing
some in-plane and out-of-plane beam instabilities problems and are then
generalized to two-dimensional plate media. Geometrical and material
non-linearities may be also accounted for at the lattice scale, thus
generating some nonlocal or higher-order gradient laws at the macroscopic

Nonlocal structural mechanics is definitely an efficient engineering theory
that may be able to capture the fundamental scale effects related to the
microstructure at the finer scale. A lot of applications may be found in the
small-scale world (especially for micromechanics or nanomechanics
applications since the beginning of the XXIth century) but also for large
scale civil engineering structures such as truss structures for instance.
Discrete mechanics is not only a way to take into account rigorously the
microstructure phenomena: it contributes to a better understanding of the
fundamental behaviour of matter, following Bergson thoughts on the capability
of our mind to better represent the reality by discontinuous objects.

"L’intelligence ne se représente clairement que le discontinu."
Henri Bergson

Minden érdeklődőt szeretettel várunk!

  • [Fizinfo] Noël Challamel előadása a BME-n, Károlyi György, 04/25/2016

Archive powered by MHonArc 2.6.19+.

Top of Page