A hybrid Finite Element-Transfer Matrix method for the modeling of vibroacoustic systems with attached noise control treatment

This paper is concerned with the development of a hybrid methodology to speed up finite element analysis in vibroacoustic applications. The approach aims at avoiding the finite element modeling of the noise control treatment, which is cumbersome from both computational (i.e. model size) and virtual prototyping (i.e. meshing) standpoints. A transfer matrix model is instead employed, allowing for a reduction of the computational burden and a substantial simplification of the multilayer modeling. The methodology relies on the assumption that the noise control treatment is flat, homogeneous and of infinite lateral extent
(i.e. finite size effects are negligible). The latter hypothesis is justified by short wavelength and high dissipation. Under these circumstances, the surface impedance at the two ends of the laterally unbounded noise control treatment can be formally obtained starting from an integral formulation. Results prove that, generally speaking, the hybrid finite elementtransfer matrix model can always capture the qualitative behavior of the vibroacoustic system. However, it is shown that, in some cases, finite size effects within the noise control treatment may be important. Hence, a correction is proposed to retrieve the missing performance.