Abstract
Abstract The $L^2$-orthogonal projection $ {\varPi }_h:L^2(\varOmega )\rightarrow {\mathbb{V}}_h$ onto a finite element (FE) space $ {\mathbb{V}}_h$ is called $H^1$-stable iff $ \|{ {\varPi }_h u}\|_{H^{1}}(\varOmega )\leq C\|{u}\|_{H^{1}}(\varOmega ) $ for any $u\in H^1(\varOmega )$ with a positive constant $C\neq C(h)$ independent of the mesh size $h>0$. Stability of this projection in the $H^1$-norm is an important component in the numerical analysis of FE methods, and it has been extensively studied before for triangular meshes in two dimensions and tetrahedral meshes in three dimensions. In this work, we analyse $H^1$-stability of adaptively refined quadrilateral meshes in two dimensions. We show that the refinement strategies Q-RG and Q-RB, introduced originally in Bank et al. (1983, Some refinement algorithms and data structures for regular local mesh refinement. Sci. Comput., 1, 3–17) and Kobbelt (1996, Interpolatory subdivision on open quadrilateral nets with arbitrary topology. Comput. Graph Forum, 15, 409–420), are $H^1$-stable for FE spaces of polynomial degree $p=2,\ldots ,9$.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.