Sound transmission loss analysis in a complex media from a flexible continuous spectrum

This study explores the use of Mode-Matching Galerkin methods to model the scattering of acoustic waves through a flexible continuous spectrum. The model involves vertical elastic plates in the central region connected to horizontal elastic plates, featuring different edge conditions at the joints. The connections between the horizontal and vertical boundaries are assumed to have clamped and pin-jointed edge conditions on the finite edges. The displacements of bridging elastic plates are obtained from the solutions of plates boundary conditions at the edges, that are expressed in the form of forth order ordinary differential equations (ODE). The obtained solutions of ODE are expressed in the form of elastic plates displacements, which depends on the edges of plates at the joints. The displacements were significantly influenced by changing the edge conditions of the plates, from clamped to pin-jointed at the joints, which optimized the transmission loss and scattering energies across the entire frequency range. The accuracy of the method is verified by ensuring the conservation of energy. Additionally, it is confirmed by comparing the truncated solutions with the reconstructed matching conditions. In this model, scattering energies travel along with the walls and through the fluid, with its behavior influenced by changes in the edge conditions. Additionally, edge conditions play a significant role in structure-borne radiation but have minimal impact on fluid-borne radiation.