Combining the 2.5D FE-BE method and the TMM method to study the vibro-acoustics of acoustically treated rib-stiffened panels

This paper is concerned with the prediction of vibro-acoustic behavior rib-stiffened panels treated multiple layers porous materials. The acoustically are assumed to be uniform and infinitely long in one direction (the longitudinal direction) but cross-section can have an arbitrary often complicated shape. Although two-and-half dimensional structural finite element method (2.5D FEM) acoustic boundary BEM) may combined perform prediction, presence treatment makes too time-consuming. More efficient methods required for such structures aim this propose a method. panel fluid domain containing incident reflected sound waves modelled using 2.5D FEM-BEM while layer transmitted dealt with, approximately, transfer matrix (TMM). coupling TMM formulated detail. Since flat baffled, BEM based on Rayleigh integral wavenumber domain. Meanwhile, two-dimensional Fourier transform which implies that also extend cover baffle; validity assumption explored. accuracy efficiency compared full FE-BE homogeneous plate attached absorbent material. It shown proposed reduce calculation time by about factor three then applied study transmission loss (STL) typical from train carriage different material layers, demonstrating design significant effect STL panel.