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.

Transmission loss of orthogonally rib-stiffened double-panel structures with cavity absorption.

Experimental validation of the modified couple stress Timoshenko beam theory for web-core sandwich panels

Optimum structural design of composites is a research subject that has drawn the attention of many researchers for more than 40 years with a growing interest. In this study, a review of the literature on this subject is presented. The papers are classified according to the type of the composite structure optimized in those studies, the loading conditions, the objective function, the structural analysis method, the design variables, the constraints, the failure criteria, and the search algorithm used by the researchers.

Optimum Design of Composite Structures: A Literature Survey (1969-2009)

Optimisation of laser-welded sandwich panels with multiple design constraints

Two-scale micropolar plate model for web-core sandwich panels

This is the second of three companion papers that examine the elastic buckling andcollapse of laser-welded sandwich panels with an adhesively bonded core and uni-directionalvertical webs. In the fi ...

/pdf/buckling-of-laser-welded-sandwich-panels-part-2-elastic-58o61t0fkv.pdf

Buckling of laser-welded sandwich panels. Part 2: Elastic buckling normal to the webs:

This is the last of three companion papers which examine the elastic buckling and collapse of laser-welded sandwich panels with an adhesively bonded core and unidirectional vertical webs. By evalua ...

/pdf/buckling-of-laser-welded-sandwich-panels-ultimate-strength-57x8bwt04v.pdf

Hans Kolsters

Papers

Optimisation of laser-welded sandwich panels with multiple design constraints

Buckling of laser-welded sandwich panels. Part 2: Elastic buckling normal to the webs:

Buckling of laser-welded sandwich panels: Ultimate strength and experiments