Plenary Lecture
Hamiltonian Formalisms Applied to Continuum Mechanics
Potential Use for Fracture Mechanics
Professor Naman Recho
ERMESS/ EPF-Ecoles d'Ingenieurs, Sceaux and
LaMI, University Blaise Pascal, Clermont II
France
E-mail: naman.recho@epf.fr
Abstract: The first
part of this paper deals with several Hamiltonian
formalisms in elasticity. We first present briefly the
formalisms of Zhong and Bui, (Bui, [1]; Zhong, [2]),
which resolve respectively the two-end problem and the
Cauchy problem in elasticity. Then we propose a new
Hamiltonian formalism, which resolves simultaneously the
two problems mentioned above and it shows the link
between the two formalisms. The potential use for
fracture mechanics purposes is then mentioned. In fact,
when traditional theories in fracture mechanics are
used, asymptotic analyses are often carried out by using
high-order differential equations governing the stress
field near the crack tip. The solution of the high-order
differential equations becomes difficult when one deals
with anisotropic or multiplayer media etc. The key of
our idea is to introduce the Hamiltonian system, usually
studied in rational mechanics, into continuum mechanics
also, one can obtain a system of first-order
differential equations, instead of the high-order
differential equation. This method is very efficient and
quite simple to obtain solution of the governing
equations of this class of problems. It allows dealing
with large range of problems, which may be difficult to
resolve by using traditional methods.
By using this approach, we have resolved various
problems. Some of them have been solved previously and
some not yet. We see that the present method is
particularly efficient for resolving multi-material
problems. So the multi-material problem can be resolved
as a single material problem through the construction of
a transfer matrix.
We believe that a large domain can be found in applying
this new approach into fracture mechanics.
Brief Biography of the Speaker:
Naman Recho is a Professor at the University Blaise
Pascal in Clermont Ferrand, France, he is also head of
ERMESS- Research laboratory (Equipe de Recherche en
Mecanique et Securite des Structures) at EPF Engineering
school in Sceaux, France.
He has worked extensively with conceptual and applied
aspects of fracture mechanics, with welded offshore
structures and reliability analysis of cracked
structures. He also teaches at Centre des Hautes Etudes
de la Construction, Paris, and is guest Professor at
Hefei University of Technology in China.
Professor Naman Recho was educated at the French
University of Pierre and Marie Curie in Paris. He
graduated in this university as Doctor Engineer in 1980
and "Docteur d'Etat Es-Sciences Physiques" in 1987. He
is full Professor since 1988. He is delegate (Delegation
CNRS) at National Centre of Scientific Research in Paris
2005-2007 and has written three textbooks within
Fracture Mechanics and Fatigue Analysis.
In the recent 10 years, he directed more than 15 theses
dealing with fracture mechanics and fatigue design of
welded joints and participated into several research
programs with industries.
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