A comparison of preconditioned iterative techniques using rapid operator application against direct solution methods
✍ Scribed by S. Foresti; S. Hassanzadeh; H. Murakami; V. Sonnad
- Book ID
- 102963818
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 630 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0029-5981
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✦ Synopsis
Abstract
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.