2026-04-13T13:22:02Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4472382026-03-27T09:46:15Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Camarotti, Juan author Aristio, Ricky author Rossi, Riccardo author Zorrilla Martínez, Rubén author Wüchner, Roland author 2025-09-23 The enforcement of essential boundary conditions is a fundamental challenge in unfitted boundary methods. This paper presents a non-intrusive, black-box strategy for imposing such conditions in unfitted meshes. The approach is intended for situations where the user does not have access to the solver’s source code or its mathematical formulation, which is often the case when using commercial software. The proposed algorithm allows solvers originally designed for body-fitted meshes to be used in unfitted cases, provided that four conditions are satisfied: (i) the solver must support user customization by means of scripting, (ii) allow the imposition of Dirichlet boundary conditions at the node level through scripting, (iii) permit the deactivation of elements outside the physical domain, and (iv) provide access to the solution gradient within active elements. The last condition can also be satisfied by externally reconstructing the gradient from nodal values and connectivity information, provided the element formulation is known, making it optional in practice. These requirements are very fair demands and are satisfied by the vast majority of production-ready, possibly commercial, codes. In the current work, we show the application of this non-intrusive algorithm in the context of the Finite Element Method (FEM) and Isogeometric Analysis (IGA) discretizations, demonstrating optimal L^2-norm error convergence. This is demonstrated using the Kratos Multiphysics code (release v10.1) from the user API, simply leveraging the capabilities mentioned above. The authors gratefully acknowledge the Design for IGA-type discretization workflows (GECKO) project. The Design for IGA-type discretization workflows has received funding from the European Union’s Horizon Europe research and Innovation programme under grant agreement No. 101073106, Call: HORIZON-MSCA-2021-DN-01. Peer Reviewed Postprint (published version) Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi numèrica::Mètodes numèrics Unfitted boundary methods Black-box solver Strong Dirichlet boundary conditions Finite element method (FEM) Isogeometric analysis (IGA) Trimmed domain A Non-intrusive approach for the imposition of strong Dirichlet boundary conditions in unfitted boundary meshes