Discontinuous isogeometric boundary elements for direct acoustic–structural coupling with Reissner–Mindlin shells

A discontinuous isogeometric boundary element method is proposed for the acoustic model, which is based on the Helmholtz time-harmonic wave propagation equation, as part of acoustic–structural interaction problems. The discontinuous formulation is combined with an offset-based collocation scheme, which enhances accuracy over the continuous approach while simplifying integration, the computation of free terms, and the representation of highly distorted elements in pole-based models. The dynamic structural model, representing the second component of the interaction problem, is formulated using isogeometric Reissner–Mindlin shell theory, which is particularly effective for modeling thin curved structures. The acoustic and structural models are directly coupled through conforming numerical meshes on the interaction surface. Isogeometric analysis is applied for both the acoustic and structural formulations, as well as to the coupling scheme, due to its ability to represent exact geometries and its superior accuracy compared to conventional numerical approaches. Numerical examples are presented to assess the performance of the proposed solution, with results compared against available analytical solutions and previously reported outcomes based on alternative coupling strategies. • A discontinuous isogeometric boundary element method is proposed for the acoustic model governed by the time-harmonic Helmholtz equation, as part of acoustic–structural interaction problems. • The dynamic structural model, as the second part of the interaction problem, is based on isogeometric Reissner–Mindlin shell, particularly effective for modeling thin curved structures. • The acoustic and structural models are directly coupled through conforming isogeometric meshes on the interaction surface. • Isogeometric analysis is employed due to its ability to represent exact geometries and its superior accuracy compared to conventional numerical approaches.