共查询到20条相似文献,搜索用时 9 毫秒
1.
This paper proposes a mortar finite element method for solvingthe two-dimensional second-order elliptic problem with jumpsin coefficients across the interface between two subregions.Non-matching finite element grids are allowed on the interface,so independent triangulations can be used in different subregions.Explicitly realizable mortar conditions are introduced to couplethe individual discretizations. The same optimal L2-norm andenergy-norm error estimates as for regular problems are achievedwhen the interface is of arbitrary shape but smooth, thoughthe regularity of the true solution is low in the whole physicaldomain. 相似文献
2.
In this work we propose and analyze a fully discrete modified Crank–Nicolson finite element (CNFE) method with quadrature for solving semilinear second‐order hyperbolic initial‐boundary value problems. We prove optimal‐order convergence in both time and space for the quadrature‐modified CNFE scheme that does not require nonlinear algebraic solvers. Finally, we demonstrate numerically the order of convergence of our scheme for some test problems. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008 相似文献
3.
4.
In this paper,optimize-then-discretize,variational discretization and the finite volume method are applied to solve the distributed optimal control problems governed by a second order hyperbolic equation.A semi-discrete optimal system is obtained.We prove the existence and uniqueness of the solution to the semidiscrete optimal system and obtain the optimal order error estimates in L ∞(J;L 2)-and L ∞(J;H 1)-norm.Numerical experiments are presented to test these theoretical results. 相似文献
5.
We present and analyze a preconditioner of the additive Schwarz type for the mortar boundary element method. As a basic splitting, on each subdomain we separate the degrees of freedom related to its boundary from the inner degrees of freedom. The corresponding wirebasket-type space decomposition is stable up to logarithmic terms. For the blocks that correspond to the inner degrees of freedom standard preconditioners for the hypersingular integral operator on open boundaries can be used. For the boundary and interface parts as well as the Lagrangian multiplier space, simple diagonal preconditioners are optimal. Our technique applies to quasi-uniform and non-uniform meshes of shape-regular elements. Numerical experiments on triangular and quadrilateral meshes confirm theoretical bounds for condition and MINRES iteration numbers. 相似文献
6.
** Email: Tahar.Boulmezaoud{at}univ-pau.fr*** Email: Mohammed.Elrhabi{at}math.jussieu.fr In this paper we propose a mortar spectral element method forsolving Maxwell's equations in 3D bounded cavities. The methodis based on a non-conforming decomposition of the domain intothe union of non-overlapping parallelepipeds. After provingan error estimate, we present some 3D computational resultswhich confirm the performance of the method. 相似文献
7.
In this paper, a multigrid algorithm is presented for the mortar element method for P1 nonconforming element. Based on the
theory developed by Bramble, Pasciak, Xu in [5], we prove that the W-cycle multigrid is optimal, i.e. the convergence rate
is independent of the mesh size and mesh level. Meanwhile, a variable V-cycle multigrid preconditioner is constructed, which
results in a preconditioned system with uniformly bounded condition number.
Received May 11, 1999 / Revised version received April 1, 2000 / Published online October 16, 2000 相似文献
8.
Leszek Marcinkowski 《Numerische Mathematik》2002,93(2):361-386
Summary. In this paper mortar element methods for the clamped plate problem are discussed. Locally, we use conforming Hsieh-Clough-Tocher
(HCT) and reduced HCT macro elements and a nonconforming Morley element. We establish error bounds for these methods.
Received December 1, 2000 / Revised version received December 3, 2001 / Published online April 17, 2002
This work was partially supported by Polish Scientific Grant 237/PO3/99/16 相似文献
9.
Wolf Hofmann 《Numerical Methods for Partial Differential Equations》1985,1(3):187-194
A well known theórem about super- and subfunctions for the solution of hyperbolic initial value problems constructs differentiable functions as upper and lower bounds (see Walter [1], 21 XIII). The proof can be done by transforming the differential equation problem into a set of integral equations, using the monotonicity-properties of the arising integral operators. This proof needs an integral representation for twice differentiable functions. It is shown that this proceeding can be generalized to get upper and lower bounds in terms of finite element functions. To do this, we give an integral representation for continuous, piecewise differentiable functions, including the discontinuities of their derivatives. Then the generalization of the classical proof yields interface conditions for the finite element functions. Finally, it is demonstrated how to realize numerically these conditions. 相似文献
10.
Youngmok Jeon Eun‐Jae Park Dongwoo Sheen 《Numerical Methods for Partial Differential Equations》2005,21(3):496-511
An elementary analysis on the cell boundary element (CBEM) was given by Jeon and Sheen. In this article we improve the previous results in various aspects. First of all, stability and convergence analysis on the rectangular grids are established. Moreover, error estimates are improved. Our improved analysis was possible by recasting of the CBEM in a Petrov‐Galerkin setting. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005 相似文献
11.
This paper provides a discrete Fourier method for constructing stable numerical solutions of strongly coupled mixed hyperbolic problems. Using Crank-Nicholson scheme the exact solution of the discretized problem is found. Then the stability of the discrete solution is analyzed and illustrative examples are included. 相似文献
12.
The Petrov-Galerkin method is used to construct a semidiscrete approximation for hyperbolic systems of equations in one space dimension. Stability is analyzed for the Cauchy problem and for an initial and boundary-value problem with positive and negative characeristic speeds of unequal magnitude. Numerical experiments are conducted on a linear problem to support the stability analysis and to compare the accuracies of various boundary approximations. Experiments on a nonlinear problem check the viability of the best boundary method. 相似文献
13.
Summary.
The mortar element method is a
non conforming finite element method with
elements based on domain decomposition. For the Laplace equation,
it yields an ill conditioned linear system. For solving the linear system,
the so called preconditioned conjugate gradient method in
a subspace is used. Preconditioners are
proposed, and estimates on condition numbers
and arithmetical complexity are given.
Finally, numerical experiments are presented.
Received
June 22, 1994 / Revised version received February 6, 1995 相似文献
14.
Zhiyue Zhang Dingwen Deng 《Numerical Methods for Partial Differential Equations》2007,23(6):1530-1559
A modified backward difference time discretization is presented for Galerkin approximations for nonlinear hyperbolic equation in two space variables. This procedure uses a local approximation of the coefficients based on patches of finite elements with these procedures, a multidimensional problem can be solved as a series of one‐dimensional problems. Optimal order H01 and L2 error estimates are derived. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
15.
The least-squares spectral element method has been applied to the one-dimensional inviscid Burgers equation which allows for discontinuous solutions. In order to achieve high order accuracy both in space and in time a space–time formulation has been applied. The Burgers equation has been discretized in three different ways: a non-conservative formulation, a conservative system with two variables and two equations: one first order linear PDE and one linearized algebraic equation, and finally a variant on this conservative formulation applied to a direct minimization with a QR-decomposition at elemental level. For all three formulations an h/p-convergence study has been performed and the results are discussed in this paper. 相似文献
16.
讨论了二维一阶线性变系数双曲方程的耗散谱元法,得到拟最优估计.数值结果表明,耗散谱元法对于具有较复杂边界条件的问题同样有效,对于有限光滑问题,耗散谱元法能够得到比传统的谱元法更好的结果. 相似文献
17.
In this paper, we are concerned with mortar edge element methods for solving three-dimensional Maxwell's equations. A new type of Lagrange multiplier space is introduced to impose the weak continuity of the tangential components of the edge element solutions across the interfaces between neighboring subdomains. The mortar edge element method is shown to have nearly optimal convergence under some natural regularity assumptions when nested triangulations are assumed on the interfaces. A generalized edge element interpolation is introduced which plays a crucial role in establishing the nearly optimal convergence. The theoretically predicted convergence is confirmed by numerical experiments.
18.
Bin Jiang 《Numerical Methods for Partial Differential Equations》2008,24(2):476-503
The mortar finite element method is a special domain decomposition method, which can handle the situation where meshes on different subdomains need not align across the interface. In this article, we will apply the mortar element method to general variational inequalities of free boundary type, such as free seepage flow, which may show different behaviors in different regions. We prove that if the solution of the original variational inequality belongs to H2(D), then the mortar element solution can achieve the same order error estimate as the conforming P1 finite element solution. Application of the mortar element method to a free surface seepage problem and an obstacle problem verifies not only its convergence property but also its great computational efficiency. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008 相似文献
19.
Younbae Jun 《Applied mathematics and computation》2010,216(8):2286-2292
In this paper, a noniterative domain decomposition algorithm for solving hyperbolic partial differential equations is presented. The algorithm includes a prediction to estimate the values at the interface and these values are corrected by a scheme that improves the accuracy. It has been shown that the algorithm is unconditionally stable. Efficiency is analyzed in terms of speedup and operation ratio. Numerical experiments illustrate that the method is stable and efficient. 相似文献
20.
Numerical Algorithms - In this paper, we analyze a space-time finite element method for fractional wave problems involving the time fractional derivative of order γ (1 < γ... 相似文献