Vincent Debut, investigador do INET-md e coordenador do seu grupo de investigação em Acústica Musical e Estudos de Sons, é co-autor, com Filipe Soares (CNRS), do artigo “Acoustic radiation from vibrating plates using minimal modal sets of elementary sources“, publicado no Journal of Sound and Vibration.
Resumo (apenas em inglês):
This work develops an efficient framework for approximating the acoustic radiation from vibrating plates using minimal sets of elementary point sources. The method is based on a modal description of the plate vibration, where the radiation from each lobe within a mode shape is represented by a single point source. Within this framework, both baffled and unbaffled plate configurations can be handled using analogous expressions for arrays of either monopole or dipole sources. To enable the systematic treatment of plates of arbitrary geometry, an automated mode shape segmentation strategy is proposed, based on the watershed transform. Aside from the computation of modal radiation efficiencies, we extend the method to deal with forced multimodal scenarios, where cross-modal interactions play an important role. Formulations are presented for both frequency and time domain calculations. This minimal discretization constitutes a low-frequency approximation for the radiation from each mode, valid up to the corresponding modal coincidence frequency, which increases with modal order. However, in forced multimodal scenarios where modes respond primarily near their natural frequencies (which also increases with order), the resulting predictions can remain accurate over broad frequency ranges. The merits and limitations of the approach are illustrated through several examples, where approximate solutions are benchmarked against reference results from either analytical or finite-element models. Beyond its evident benefits in computational efficiency, the method is conceptually simple and readily compatible with conventional structural vibration models, since acoustic radiation is calculated directly from modal vibratory data.