Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Equivalence of Strong and Weak Formulations

In course

ME-372: Finite element method

L'étudiant acquiert une initiation théorique à la méthode des éléments finis qui constitue la technique la plus courante pour la résolution de problèmes elliptiques en mécanique. Il apprend à appliquer cette méthode à des cas simples et à l'exploiter pour ...

Description

This lecture covers the equivalence between strong and weak formulations in the context of the finite element method, including integral formulation of the problem, shifting, integration by parts, and the Galerkin method. It also discusses the choice of shape for virtual displacement and the approximation of real and virtual axial displacements using linearly independent shape functions.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

François Gallaire

Né le 26 février 1975, François Gallaire obtient, en 1998, le diplôme dingénieur de lEcole Polytechnique à Paris et, en 1999, un master en « Physique des liquides » à lUniversité Pierre et Marie Curie, toujours à Paris. Il rejoint ensuite le Laboratoire dhydrodynamique (LadHyX) à lEcole polytechnique où il soutient, en 2003, une thèse sur le thème des instabilités des jets tournants et sur le contrôle de léclatement tourbillonnaire sous la direction de Jean-Marrc Chomaz. En 2003, il est nommé chargé de recherche au CNRS au Laboratoire J.A. Dieudonné de lUniversité de Nice Sophia-Antipolis.En 2009, il rejoint l'EPFL pour y fonder le laboratoire des mécanique des fluides et instabilités (LFMI). Ses recherches se concentrent sur létude des propriétés fondamentales de stabilité des écoulements de fluides et sont guidées par les applications réelles, en particulier le contrôle des écoulements. Récemment, il a réalisé dimportantes contributions dans les domaines de la micro-fluidique (lanalyse de la manipulation par laser dune goutte dans un micro-canal) et la dynamique des bio-fluides (le descriptif mécanique de lanévrisme de laorte abdominale).

Official source

Related concepts (32)

Galerkin method

In mathematics, in the area of numerical analysis, Galerkin methods are named after the Soviet mathematician Boris Galerkin. They convert a continuous operator problem, such as a differential equation, commonly in a weak formulation, to a discrete problem by applying linear constraints determined by finite sets of basis functions.

Finite element method

The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. The FEM is a general numerical method for solving partial differential equations in two or three space variables (i.e., some boundary value problems).

Meshfree methods

In the field of numerical analysis, meshfree methods are those that do not require connection between nodes of the simulation domain, i.e. a mesh, but are rather based on interaction of each node with all its neighbors. As a consequence, original extensive properties such as mass or kinetic energy are no longer assigned to mesh elements but rather to the single nodes. Meshfree methods enable the simulation of some otherwise difficult types of problems, at the cost of extra computing time and programming effort.

Integral

In mathematics, an integral is the continuous analog of a sum, which is used to calculate areas, volumes, and their generalizations. Integration, the process of computing an integral, is one of the two fundamental operations of calculus, the other being differentiation. Integration started as a method to solve problems in mathematics and physics, such as finding the area under a curve, or determining displacement from velocity. Today integration is used in a wide variety of scientific fields.

Line integral

In mathematics, a line integral is an integral where the function to be integrated is evaluated along a curve. The terms path integral, curve integral, and curvilinear integral are also used; contour integral is used as well, although that is typically reserved for line integrals in the complex plane. The function to be integrated may be a scalar field or a vector field. The value of the line integral is the sum of values of the field at all points on the curve, weighted by some scalar function on the curve (commonly arc length or, for a vector field, the scalar product of the vector field with a differential vector in the curve).

Related lectures (52)

Designing Learning Experiences: CS411 Class Project

Introduces the CS411 Class Project, where students design and test a lesson using learning theories.

Matrix to Density Operator

Explains the transformation from a matrix to the density operator in quantum physics.

Generalized Integrals and Convergence Criteria

Covers generalized integrals, convergence criteria, series convergence, and harmonic series in analysis.

Chain Polymerisation: Mechanism and Kinetics

Explores the mechanism and kinetics of chain polymerisation, focusing on inhibitors and competitive inhibition in enzyme reactions.

Density Operator: Matrix to the System State