Seminars & Events

Mathematics and Computer Science Division
"Comparison of two domain decomposition methods for a linearized contact problem"

DATE: September 8, 2010
TIME: 10:30 AM - 11:30 AM
SPEAKER: Jungho Lee, LANS Postdoc
LOCATION: Building 240 Seminar Room 4301, Argonne National Laboratory
HOST: Barry Smith

Description:
A three-level domain decomposition is considered. Bodies in contact with each other are divided into subdomains, which in turn are the union of elements. Using an approach based purely on FETI (finite element tearing and interconnecting) algorithms with only Lagrange multipliers as unknowns, which has been developed by the engineering community, does not lead to a scalable algorithm with respect to the number of subdomains in each body. We present a proof that such a method has a condition number which depends linearly on the number of subdomains across each body and logarithmically on the number of elements across each subdomain. We also propose a new method based on the saddle point formulation of the FETI methods with both displacement vectors and Lagrange multipliers as unknowns. The resulting system is solved with a block-diagonal preconditioner which combines the one-level FETI and the BDDC (balancing domain decomposition by constraints) methods. We show that this new method is scalable with respect to the number of subdomains.

Save the event to your calendar [schedule.ics]