Modelling of Sound Transmission Through Lightweight Elements with Stiffeners

TLDR: In this paper, the sound reduction index of lightweight panels with stiffeners is calculated using the wave approach applied to an infinite thin plate line connected to periodically spaced beams and excited in flexure by a single or random (diffuse field) incident plane acoustical wave.

Abstract: The sound reduction index of lightweight panels with stiffeners is calculated using the wave approach applied to an infinite thin plate line connected to periodically spaced beams and excited in flexure by a single or random (diffuse field) incident plane acoustical wave. The reaction forces and moments at the line connections are calculated from the flexural and torsional line impedance of the beams. The finite size of the panel is taken into account using a spatial windowing technique applied to the infinite panel. The case of two stiffened panels with a cavity in between and no structural connections between panels is also considered using the same approach; using SEA, the structural flanking path at the panel boundaries through any receiving structure can also be taken into account. Comparisons to measured results are given and discussed.