title: Transmission loss of orthogonally rib-stiffened double-panel structures with cavity absorption.
abstract: The transmission loss of sound through infinite orthogonally rib-stiffened double-panel structures having cavity-filling fibrous sound absorptive materials is theoretically investigated. The propagation of sound across the fibrous material is characterized using an equivalent fluid model, and the motions of the rib-stiffeners are described by including all possible vibrations, i.e., flexural displacements, bending, and torsional rotations. The effects of fluid-structure coupling are account for by enforcing velocity continuity conditions at fluid-panel interfaces. By taking full advantage of the periodic nature of the double-panel, the space-harmonic approach and virtual work principle are applied to solve the sets of resultant governing equations, which are eventually truncated as a finite system of simultaneous algebraic equations and numerically solved insofar as the solution converges. To validate the proposed model, a comparison between the present model predictions and existing numerical and experimental results for a simplified version of the double-panel structure is carried out, with overall agreement achieved. The model is subsequently employed to explore the influence of the fluid-structure coupling between fluid in the cavity and the two panels on sound transmission across the orthogonally rib-stiffened double-panel structure. Obtained results demonstrate that this fluid-structure coupling affects significantly sound transmission loss (STL) at low frequencies and cannot be ignored when the rib-stiffeners are sparsely distributed. As a highlight of this research, an integrated optimal algorithm toward lightweight, high-stiffness and superior sound insulation capability is proposed, based on which a preliminary optimal design of the double-panel structure is performed.
authors.affiliation: MOE Key Laboratory for Strength and Vibration, School of Aerospace, Xi'an Jiaotong University, Xi'an Shaanxi 710049, People's Republic of China.
authors.forename: F X
authors.initials: FX
authors.lastname: Xin
authors.forename: T J
authors.initials: TJ
authors.lastname: Lu
mesh_terms: D000042:Absorption; D000162:Acoustics; D000401:Aircraft; D003252:Construction Materials; D004548:Elasticity; D005583:Fourier Analysis; D008962:Models, Theoretical; D012767:Ships; D014732:Vibration