Research reports

Sparse high order FEM for elliptic sPDEs

by M. Bieri and Ch. Schwab

(Report number 2008-22)

Abstract
We describe the analysis and the implementation of two Finite Element (FE) algorithms for the deterministic numerical solution of elliptic boundary value problems with stochastic coefficients. They are based on separation of deterministic and stochastic parts of the input data by a Karhunen-Loeve expansion, truncated after M terms. With a change of measure we convert the problem to a sequence of M-dimensional, parametric deterministic problems. Two sparse, high order polynomial approximations of the random solution's joint pdf's, parametrized in the input data's Karhunen-Loeve expansion coordinates, are analyzed: a sparse stochastic Galerkin FEM (sparse sGFEM) and a sparse stochastic Collocation FEM (sparse sCFEM). A-priori and a-posteriori error analysis is used to tailor the sparse polynomial approximations of the random solution's joint pdf's to the stochastic regularity of the input data. sCFEM and sGFEM yield deterministic = approximations of the random solutions joint pdf's that converge spectrally in the number of deterministic problems to be solved. Numerical examples with random inputs of small correlation length in diffusion problems are presented. High order gPC approximations of solutions with stochastic parameter spaces of dimension up to M 80 are computed on workstations.

Keywords:

BibTeX
@Techreport{BS08_386,
  author = {M. Bieri and Ch. Schwab},
  title = {Sparse high order FEM for elliptic sPDEs},
  institution = {Seminar for Applied Mathematics, ETH Z{\"u}rich},
  number = {2008-22},
  address = {Switzerland},
  url = {https://www.sam.math.ethz.ch/sam_reports/reports_final/reports2008/2008-22.pdf },
  year = {2008}
}

Disclaimer
© Copyright for documents on this server remains with the authors. Copies of these documents made by electronic or mechanical means including information storage and retrieval systems, may only be employed for personal use. The administrators respectfully request that authors inform them when any paper is published to avoid copyright infringement. Note that unauthorised copying of copyright material is illegal and may lead to prosecution. Neither the administrators nor the Seminar for Applied Mathematics (SAM) accept any liability in this respect. The most recent version of a SAM report may differ in formatting and style from published journal version. Do reference the published version if possible (see SAM Publications).

JavaScript has been disabled in your browser