RESUMEN

A new approximate mortar condition is proposed for the lowest order Crouzeix–Raviart finite element 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 subdomain, those closest to a mortar side of the subdomain, are also required in the calculation.