La méthode des caractéristiques pour les problèmes de convection-diffusion stationnaires
Lagrange multipliers for higher order elliptic operators
In this paper, the Babuška’s theory of Lagrange multipliers is extended to higher order elliptic Dirichlet problems. The resulting variational formulation provides an efficient numerical squeme in meshless methods for the approximation of elliptic problems with essential boundary conditions.
Lagrange multipliers for higher order elliptic operators
In this paper, the Babuška's theory of Lagrange multipliers is extended to higher order elliptic Dirichlet problems. The resulting variational formulation provides an efficient numerical squeme in meshless methods for the approximation of elliptic problems with essential boundary conditions.
L...-Convergence of Collocation and Galerkin Approximations to Linear Two-point Parabolic Systems.
Least square method for solving contact problems with friction obeying the Coulomb law
The paper deals with numerical realization of contact problems with friction obeying the Coulomb law. The original problem is formulated as the fixed-point problem for a certain operator generated by the variational inequality. This inequality is transformed to a system of variational nonlinear equations generating other operators, in a sense "close" to the above one. The fixed-point problem of these operators is solved by the least-square method in which equations and the corresponding quadratic...
L’élément -bulle/
L...-Error Estimate for an Approximation of a Parabolic Variational Inequality.
Linear scheme for finite element solution of nonlinear parabolic-elliptic problems with nonhomogeneous Dirichlet boundary condition
The computation of nonlinear quasistationary two-dimensional magnetic fields leads to a nonlinear second order parabolic-elliptic initial-boundary value problem. Such a problem with a nonhomogeneous Dirichlet boundary condition on a part of the boundary is studied in this paper. The problem is discretized in space by the finite element method with linear functions on triangular elements and in time by the implicit-explicit method (the left-hand side by the implicit Euler method and the right-hand...
Local approximation estimators for algebraic multigrid.
Local error estimates and adaptive refinement for first-order system least squares (FOSLS).
Local error estimates for finite element discretization of the Stokes equations
Local Galerkin and adjoint local Galerkin procedures for elliptic equations
Local refinement techniques for elliptic problems on cell-centered grids. III. Algebraic multilevel BEPS preconditioners.
Locally pointwise superconvergence of the tensor-product finite element in three dimensions
Consider a second-order elliptic boundary value problem in three dimensions with locally smooth coefficients and solution. Discuss local superconvergence estimates for the tensor-product finite element approximation on a regular family of rectangular meshes. It will be shown that, by the estimates for the discrete Green’s function and discrete derivative Green’s function, and the relationship of norms in the finite element space such as -norms, -norms, and negative-norms in locally smooth subsets...
Locking effects in the finite element approximation of elasticity problems.
Locking free matching of different three dimensional models in structural mechanics
The present paper proposes and analyzes a general locking free mixed strategy for computing the deformation of incompressible three dimensional structures placed inside flexible membranes. The model involves as in Chapelle and Ferent [Math. Models Methods Appl. Sci.13 (2003) 573–595] a bending dominated shell envelope and a quasi incompressible elastic body. The present work extends an earlier work of Arnold and Brezzi [Math Comp.66 (1997) 1–14] treating the shell part and proposes a global...
Locking-Free Finite Elements for Unilateral Crack Problems in Elasticity
We consider mixed and hybrid variational formulations to the linearized elasticity system in domains with cracks. Inequality type conditions are prescribed at the crack faces which results in unilateral contact problems. The variational formulations are extended to the whole domain including the cracks which yields, for each problem, a smooth domain formulation. Mixed finite element methods such as PEERS or BDM methods are designed to avoid locking for nearly incompressible materials in plane elasticity....
Machine Computation Using the Exponentially Convergent Multiscale Spectral Generalized Finite Element Method
A multiscale spectral generalized finite element method (MS-GFEM) is presented for the solution of large two and three dimensional stress analysis problems inside heterogeneous media. It can be employed to solve problems too large to be solved directly with FE techniques and is designed for implementation on massively parallel machines. The method is multiscale in nature and uses an optimal family of spectrally defined local basis functions over a coarse grid. It is proved that the method has an...
Mathematical analysis of a finite element method without spurious solutions for computation of dielectric waveguides.
Mathematical Modeling of Atmospheric Flow and Computation of Convex Envelopes
Atmospheric flow equations govern the time evolution of chemical concentrations in the atmosphere. When considering gas and particle phases, the underlying partial differential equations involve advection and diffusion operators, coagulation effects, and evaporation and condensation phenomena between the aerosol particles and the gas phase. Operator splitting techniques are generally used in global air quality models. When considering organic aerosol...