Preconditioners for the Dual - Primal FETI

K e y w o r d s F E T I D P , ~Ionmatching grids, Mortar matching condition, Preconditioner. 1. I N T R O D U C T I O N The finite-element tearing and interconnecting (FETI) method is one of the substructuring methods, which was first introduced by Farhat and Roux [3]. The main idea is to match the continuity condition across subdomain boundaries by Lagrange multipliers. By eliminating primal variables of subdomains, an operator for the Lagrange multipliers is obtained. In [4], F a r h a t et al. i n t r o d u c e d a d i f fe rent s u b s t r u c t u r i n g m e t h o d ca l led t h e d u a l p r i m a l F E T I ( F E T I D P ) m e t h o d . In t h e F E T I D P m e t h o d , t h e c o n t i n u i t y c o n d i t i o n across t h e s u b d o m a i n b o u n d a r i e s is m a t c h e d b y p r i m a l va r i ab l e s a t co rne r s a n d d u a l v a r i a b l e s ( L a g r a n g e mu l t i p l i e r s ) This work was partially supported by KRF-2001-041-D00038 and KOSEF R01-2000-00008. 0898-1221/06/$ see front matter (~) 2006 Elsevier Ltd. All rights reserved. Typeset by .Ah/~TEX doi: 10.1016/j.camwa.2006.03.008 698 Y.-w. CHANG et al. on edges. Mandel and Tezaur [5] showed its optimal condition number bound,