20.500.12556/RUL-153400 IgA-BEM for 3D Helmholtz problems using conforming and non-conforming multi-patch discretizations and B-spline tailored numerical integration An Isogeometric Boundary Element Method (IgA-BEM) is considered for the numerical solution of Helmholtz problems on 3D bounded or unbounded domains, admitting a smooth multi-patch representation of their finite boundary surface. The discretization spaces are formed by $C^0$ inter-patch continuous functional spaces whose restriction to a patch simplifies to the span of tensor product B-splines composed with the given patch NURBS parameterization. Both conforming and non-conforming spaces are allowed, so that local refinement is possible at the patch level. For regular and singular integration, the proposed model utilizes a numerical procedure defined on the support of each trial B-spline function, which makes possible a function-by-function implementation of the matrix assembly phase. Spline quasi-interpolation is the common ingredient of all the considered quadrature rules; in the singular case it is combined with a B-spline recursion over the spline degree and with a singularity extraction technique, extended to the multi-patch setting for the first time. A threshold selection strategy is proposed to automatically distinguish between nearly singular and regular integrals. The non-conforming $C^0$ joints between spline spaces on different patches are implemented as linear constraints based on knot removal conditions, and do not require a hierarchical master-slave relation between neighbouring patches. Numerical examples on relevant benchmarks show that the expected convergence orders are achieved with uniform discretization and a small number of uniformly spaced quadrature nodes. Helmholtz equation Isogeometric Analysis IgA Boundary Element Method BEM non-conforming discretization singular integral nearly singular integral numerical integration B-spline quasi-interpolation true false true Angleški jezik Ni določen Članek v reviji 2024-01-03 13:52:43 2024-01-03 13:52:48 2024-01-04 03:38:34 0000-00-00 00:00:00 2023 0 0 Str. 164-184 Vol. 147 Oct. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 519.6 0898-1221 10.1016/j.camwa.2023.07.012 178695171 1-s2.0-S0898122123003061-main.pdf 1-s2.0-S0898122123003061-main.pdf 1 8304DDCF88E0F8099E66FB099E5EFFE2 efe1b2434b404977799790e175f48e5cf0e42539903336c0e6870766aab9d711 6bd0f9ec-aa37-11ee-81ea-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179374 https://www.sciencedirect.com/science/article/pii/S0898122123003061 1 ffc81238-aa36-11ee-81ea-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179372 Fakulteta za matematiko in fiziko Fakulteta za strojništvo 0 0 0