TY - GEN A1 - Dornisch, Wolfgang A1 - Stöckler, Joachim T1 - An isogeometric mortar method for the coupling of multiple NURBS domains with optimal convergence rates T2 - Numerische Mathematik N2 - We investigate the mortar finite element method for second order elliptic boundary value problems on domains which are decomposed into patchesk with tensor-product NURBS parameterizations. We follow the methodology of IsoGeometric Analysis (IGA) and choose discrete spaces Xh,k on each patch k as tensor-product NURBS spaces of the same or higher degree as given by the parameterization. Our work is an extension of Brivadis et al. (Comput Methods Appl Mech Eng 284:292–319, 2015) and highlights several aspects which did not receive full attention before. In particular, by choosing appropriate spaces of polynomial splines as Lagrange multipliers, we obtain a uniform infsup-inequality. Moreover, we provide a new additional condition on the discrete spaces Xh,k which is required for obtaining optimal convergence rates of the mortar method. Our numerical examples demonstrate that the optimal rate is lost if this condition is neglected. KW - Isogeometric analysis KW - Mortar Method KW - Approximate duals KW - domain coupling Y1 - 2021 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/28015 SN - 0945-3245 SN - 0029-599X VL - 149 IS - 4 SP - 871 EP - 931 ER -