All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 32 Next

Displaying 621 – 640 of 1411

Showing per page

FETI-DP domain decomposition methods for elasticity with structural changes: P-elasticity

Axel Klawonn, Patrizio Neff, Oliver Rheinbach, Stefanie Vanis (2011)

ESAIM: Mathematical Modelling and Numerical Analysis

We consider linear elliptic systems which arise in coupled elastic continuum mechanical models. In these systems, the strain tensor εP := sym (P-1∇u) is redefined to include a matrix valued inhomogeneity P(x) which cannot be described by a space dependent fourth order elasticity tensor. Such systems arise naturally in geometrically exact plasticity or in problems with eigenstresses. The tensor field P induces a structural change of the elasticity equations. For such a model the FETI-DP method is...

Fictitious domain methods using cut elements: III. A stabilized Nitsche method for Stokes’ problem

Erik Burman, Peter Hansbo (2014)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

We extend our results on fictitious domain methods for Poisson’s problem to the case of incompressible elasticity, or Stokes’ problem. The mesh is not fitted to the domain boundary. Instead boundary conditions are imposed using a stabilized Nitsche type approach. Control of the non-physical degrees of freedom, i.e., those outside the physical domain, is obtained thanks to a ghost penalty term for both velocities and pressures. Both inf-sup stable and stabilized velocity pressure pairs are considered....

Finite element analysis for unilateral problems with obstacles on the boundary

Jaroslav Haslinger (1977)

Aplikace matematiky

Finite element analysis of unilateral problems with obstacles on the boundary is given. Provided the exact solution is smooth enough, we obtain the rate of convergence 0 ( h ) for the case of one and two (lower and upper) obstacles on the boundary. At the end of this paper the proof of convergence without any regularity assumptions on the exact solution u is given.

Finite element analysis of a static contact problem with Coulomb friction

Ivan Hlaváček (2000)

Applications of Mathematics

A unilateral contact problem with a variable coefficient of friction is solved by a simplest variant of the finite element technique. The coefficient of friction may depend on the magnitude of the tangential displacement. The existence of an approximate solution and some a priori estimates are proved.

Finite element analysis of free material optimization problem

Jan Mach (2004)

Applications of Mathematics

Free material optimization solves an important problem of structural engineering, i.e. to find the stiffest structure for given loads and boundary conditions. Its mathematical formulation leads to a saddle-point problem. It can be solved numerically by the finite element method. The convergence of the finite element method can be proved if the spaces involved satisfy suitable approximation assumptions. An example of a finite-element discretization is included.

Finite element analysis of primal and dual variational formulations of semicoercive elliptic problems with nonhomogeneous obstacles on the boundary

Van Bon Tran (1988)

Aplikace matematiky

The Poisson equation with non-homogeneous unilateral condition on the boundary is solved by means of finite elements. The primal variational problem is approximated on the basis of linear triangular elements, and O ( h ) -convergence is proved provided the exact solution is regular enough. For the dual problem piecewise linear divergence-free approximations are employed and O ( h 3 / 2 ) -convergence proved for a regular solution. Some a posteriori error estimates are also presented.

Finite element analysis of sloshing and hydroelastic vibrations under gravity

Alfredo Bermúdez, Rodolfo Rodríguez (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

This paper deals with a finite element method to solve fluid-structure interaction problems. More precisely it concerns the numerical computation of harmonic hydroelastic vibrations under gravity. It is based on a displacement formulation for both the fluid and the solid. Gravity effects are included on the free surface of the fluid as well as on the liquid-solid interface. The pressure of the fluid is used as a variable for the theoretical analysis leading to a well posed mixed linear eigenvalue...

Finite element analysis of the Signorini problem in semi-coercive cases

Ivan Hlaváček, Ján Lovíšek (1980)

Aplikace matematiky

The plane Signorini problem is considered in the cases, when there exist non-trivial rigid admissible displacements. The existence and uniqueness of the solution and the convergence of piecewise linear finite element approximations is discussed.

Finite element approximation for a div-rot system with mixed boundary conditions in non-smooth plane domains

Michal Křížek, Pekka Neittaanmäki (1984)

Aplikace matematiky

The authors examine a finite element method for the numerical approximation of the solution to a div-rot system with mixed boundary conditions in bounded plane domains with piecewise smooth boundary. The solvability of the system both in an infinite and finite dimensional formulation is proved. Piecewise linear element fields with pointwise boundary conditions are used and their approximation properties are studied. Numerical examples indicating the accuracy of the method are given.

Finite element approximation of a contact vector eigenvalue problem

Hennie de Schepper, Roger Van Keer (2003)

Applications of Mathematics

We consider a nonstandard elliptic eigenvalue problem of second order on a two-component domain consisting of two intervals with a contact point. The interaction between the two domains is expressed through a coupling condition of nonlocal type, more specifically, in integral form. The problem under consideration is first stated in its variational form and next interpreted as a second-order differential eigenvalue problem. The aim is to set up a finite element method for this problem. The error...

Currently displaying 621 – 640 of 1411