The Crouzeix-Raviart FE on nonmatching grids with an approximate mortar condition. (English) Zbl 1160.65344

Rahman, Talal; Bjørstad, Petter; Xu, Xuejun

SIAM J. Numer. Anal. 46, No. 1, 496-516 (2008).

Summary: A new approximate mortar condition is proposed for the lowest order Crouzeix-Raviart finite element (FE) on nonmatching grids, which uses only the nodal values on the interface for the calculation of the mortar projection. This approach allows for improved and more flexible algorithms compared to those for the standard mortar condition where nodal values in the interior of a sub-domain, those closest to a mortar side of the subdomain, are also required in the calculation.

MSC:

65N30	Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs
65N55	Multigrid methods; domain decomposition for boundary value problems involving PDEs
65F10	Iterative numerical methods for linear systems
65F35	Numerical computation of matrix norms, conditioning, scaling
35J25	Boundary value problems for second-order elliptic equations

Keywords:

Crouzeix-Raviart finite element; nonmatching grids; Mortar condition; additive Schwarz method; numerical examples; preconditioning; domain decomposition; algorithm