Abstract:

The addition of small mass inclusions into the poro-elastic layer was found to create an increase in insertion loss (IL) over a broadband frequency range, usually below 1000 Hz. In this paper, results of two models: a simplified closed form approximation to the frame dynamics and a fully couple finite element analysis, are compared to experimental results. The motivation is the large computational effort that is required by the fully coupled 3-D finite element model of the poroelastic material makes optimization prohibitive in terms of time/computational power. Proof of equivalency of the analytical approximation, the FEA model and experimental data allows the former to be used in the optimization of inclusion design. Results from the fully coupled 3-D model, an approximation to the Biot model, and an experimental investigation are compared and discussed.