Pereira A., Tadeu A.

The sound insulation provided by a single layer partition that is infinite along its plane and divides an infinite acoustic medium is analysed in this paper. The partition is confined laterally (on two sides of the partition) and the solution is obtained by means of a Boundary Element Method formulation in the frequency domain, where only the discretization of the restricted surfaces of the panel is required since Green’s functions are used for the layered medium. The confinement is achieved by ascribing null displacements to two boundaries defined by the width of the panel. These boundaries may define panels of different sizes. The responses are calculated assuming that the incident wave field is generated by cylindrical line loads placed in either the acoustic or the elastic medium and acting in the direction. Material losses are taken into account by using a complex Lamé constant and a complex shear modulus. The analysis is performed in both the frequency and time domains, taking the solution for no confinement as a reference. Simulations are performed for a partition of varying materials, length and thickness. Wave propagation features, including the influence of the vibration modes of a confined partition and the coincidence effect, are analysed.