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A comparison of preconditioned iterative techniques using rapid operator application against direct solution methods
Author(s) -
Foresti S.,
Hassanzadeh S.,
Murakami H.,
Sonnad V.
Publication year - 1991
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620320513
Subject(s) - preconditioner , operator (biology) , factorization , finite element method , scheme (mathematics) , iterative method , computation , degrees of freedom (physics and chemistry) , polynomial , matrix (chemical analysis) , computer science , mathematical optimization , algorithm , mathematics , engineering , mathematical analysis , structural engineering , biochemistry , chemistry , physics , materials science , repressor , quantum mechanics , transcription factor , composite material , gene
The p ‐version of the finite element method which uses high order hierarchic basis functions within an element allows for ease of adaptive computation, and high accuracy with relatively few degrees of freedom. However, the solution time and storage requirements for large 3‐D problems can be very high when direct methods are used to factor global matrices. Iterative techniques with rapid operator application have minimal storage requirements because neither element nor global matrices are formed, but may not converge rapidly enough. We study an approach that attempts to combine the two methods by using direct factorization of the matrix corresponding to low level polynomials as a preconditioner to an iterative method at a higher polynomial level. This resulting solution scheme converges more rapidly than an unpreconditioned scheme but has much lower storage requirements than direct methods. We illustrate the effectiveness of this scheme on some large three‐dimensional problems in structural analysis.