Conference_programme: 23: Structural acoustics and vibration
Lecture: Observation of Nonlinear vibro-Acoustic phenomena in the Presence of Elastic Membrane with Different Boundary Conditions
Author(s): Moezzi Reza, Auriemma Fabio
Summary:
Linear behaviors are typically encountered in duct acoustics where sound waves propagate in rigid\nducts. In this experimental study, a circular visco-elastic membrane is used as an essentially\nnonlinear attachment to generate local nonlinearities for a primary linear system constituted by a straight rigid duct. In specific acoustic conditions, the membrane behaves as Nonlinear Energy Sink (NES), where the acoustic power from the primary linear system is irreversibly transferred to and\ndissipated. The phenomenon is known as Targeted Energy Transfer (TET). Three different test rig configurations have been investigated, in order to show the effect of three different boundary conditions (BCs) of the primary system on the occurrence of TET. These BCs represent the way the primary system is connected to the excitation source and to the nonlinear attachment. Despite the TET, the acoustic waves still propagate linearly in the duct. For this reason, the classical wave decomposition technique has been used to describe the acoustic field in the primary system. The amplitude of the acoustic pressure in the duct and the reflection coefficient at the end section of it have been measured as a function of excitation amplitude and frequency in order to assess the effect of the different BCs.
Corresponding author
Name: Mr Reza Moezzi
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Estonia
