A hybrid finite element–transfer matrix model for vibroacoustic systems with flat and homogeneous acoustic treatments

Abstract

Practical vibroacoustic systems involve passive acoustic treatments consisting of highly dissipative media such as poroelastic materials. The numerical modeling of such systems at low to mid frequencies typically relies on substructuring methodologies based on finite element models. Namely, the master subsystems (i.e., structural and acoustic domains) are described by a finite set of uncoupled modes, whereas condensation procedures are typically preferred for the acoustic treatments. However, although accurate, such methodology is computationally expensive when real life applications are considered. A potential reduction of the computational burden could be obtained by approximating the effect of the acoustic treatment on the master subsystems without introducing physical degrees of freedom. To do that, the treatment has to be assumed homogeneous, flat, and of infinite lateral extent. Under these hypotheses, simple analytical tools like the transfer matrix method can be employed. In this paper, a hybrid finite element-transfer matrix methodology is proposed. The impact of the limiting assumptions inherent within the analytical framework are assessed for the case of plate-cavity systems involving flat and homogeneous acoustic treatments. The results prove that the hybrid model can capture the qualitative behavior of the vibroacoustic system while reducing the computational effort.

Comparative Study of Sound Transmission Losses of Sandwich Composite Double Panel Walls

“…Their model enabled the computation of the mean and variance of diffused field STL and also avoided the detailed finite element modelling of the structure. Other hybrid models which have been investigated are the finite element transfer matrix method (FE-TMM) [122,123] and the patch transfer models [124,125].…”

Sound transmission of periodic composite structure lined with porous core: Rib-stiffened double panel case

“…The effect of flow on these structures was subsequently studied by Liu [20]. The numerical methods [14] for these structures, based on the Biot theory, were also developed.…”

“…In these absorption filling (cavity) problems, the EFM, owing to its simplicity, is widely used together with numerical [11] or semi-analytical methods [8,12,13]. For elastic frame porous problems, the Biot theory should be used [14,15] as the EFM is invalid. Using the Biot theory, together with the simplifications of Deresiewicz [16] and Allard [17], Bolton [18] studied a two-dimensional (2D) multipanel structure with elastic porous materials, where the closed form expressions for 2D poroelastic field are obtained.…”

“…The effect of flow on these structures was subsequently studied by Liu [20]. The numerical methods [14] for these structures, based on the Biot theory, were also developed.Meanwhile, multipanel structures with attachments were prominent as well.The focus of the current ongoing study, as the absorption fillings are always absent under the circumstances, is primarily on those with ribs, resilient mountings, or elastic coatings. One of the most useful methods for these problems…”

Low to Middle Vibro-Acoustic Noise Prediction in Ship Cabin by Using Plate-Cavity Coupling Model

“…The method depends more on engineering personnel experience when the predicted ship differs greatly from the parent ship and engineering accuracy requirements will not be met in case of inaccurate parameter selection. Theoretical analysis method directly establishes coupling dynamic equations on structure and air to obtain acoustic radiation values of the structure through modal expansion and integral transformation [9][10][11]. The method has high solving efficiency and good calculation accuracy, but only applicable to geometric structures with simple analytical solutions and thus less applied in ship noise prediction.…”