86 research outputs found
A subspace correction method for discontinuous Galerkin discretizations of linear elasticity equations
We study preconditioning techniques for discontinuous Galerkin discretizations of isotropic linear elasticity problems in primal (displacement) formulation. We propose subspace correction methods based on a splitting of the vector valued piecewise linear discontinuous finite element space, that are optimal with respect to the mesh size and the Lamé parameters. The pure displacement, the mixed and the traction free problems are discussed in detail. We present a convergence analysis of the proposed preconditioners and include numerical examples that validate the theory and assess the performance of the preconditioners
HAZniCS -- Software Components for Multiphysics Problems
We introduce the software toolbox HAZniCS for solving interface-coupled
multiphysics problems. HAZniCS is a suite of modules that combines the
well-known FEniCS framework for finite element discretization with solver and
graph library HAZmath. The focus of the paper is on the design and
implementation of a pool of robust and efficient solver algorithms which tackle
issues related to the complex interfacial coupling of the physical problems
often encountered in applications in brain biomechanics. The robustness and
efficiency of the numerical algorithms and methods is shown in several
numerical examples, namely the Darcy-Stokes equations that model flow of
cerebrospinal fluid in the human brain and the mixed-dimensional model of
electrodiffusion in the brain tissue
Multigrid Preconditioner for Nonconforming Discretization of Elliptic Problems with Jump Coefficients
In this paper, we present a multigrid preconditioner for solving the linear
system arising from the piecewise linear nonconforming Crouzeix-Raviart
discretization of second order elliptic problems with jump coefficients. The
preconditioner uses the standard conforming subspaces as coarse spaces.
Numerical tests show both robustness with respect to the jump in the
coefficient and near-optimality with respect to the number of degrees of
freedom.Comment: Submitted to DD20 Proceeding
Multigrid methods for saddle point problems: Darcy systems
We design and analyze multigrid methods for the saddle point problems resulting from Raviart–Thomas–Nédélec mixed finite element methods for the Darcy system in porous media flow. Uniform convergence of the W-cycle algorithm in a nonstandard energy norm is established. Extensions to general second order elliptic problems are also addressed
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