Isogeometric FEM-BEM coupled structural-acoustic analysis of shells using subdivision surfaces

摘要

We introduce a coupled finite and boundary element formulation for acousticscattering analysis over thin shell structures. A triangular Loop subdivisionsurface discretisation is used for both geometry and analysis fields. TheKirchhoff-Love shell equation is discretised with the finite element method andthe Helmholtz equation for the acoustic field with the boundary element method.The use of the boundary element formulation allows the elegant handling ofinfinite domains and precludes the need for volumetric meshing. In the presentwork the subdivision control meshes for the shell displacements and theacoustic pressures have the same resolution. The corresponding smoothsubdivision basis functions have the $C^1$ continuity property required for theKirchhoff-Love formulation and are highly efficient for the acoustic fieldcomputations. We validate the proposed isogeometric formulation through aclosed-form solution of acoustic scattering over a thin shell sphere.Furthermore, we demonstrate the ability of the proposed approach to handlecomplex geometries with arbitrary topology that provides an integratedisogeometric design and analysis workflow for coupled structural-acousticanalysis of shells.