Toward an adjustable nonlinear low frequency acoustic absorber

Riccardo Mariani (1, 2) , Sergio Bellizzi (2, 1) , Bruno Cochelin (3, 2) , Philippe Herzog (2, 1) , Pierre-Olivier Mattei (2, 1)

1 Sons
2 LMA - Laboratoire de Mécanique et d'Acoustique [Marseille]
3 M&S - Matériaux et Structures

This paper presents experimental results showing that a loudspeaker used as a suspended piston working outside its range of linearity can also be used as a nonlinear acoustic absorber. The main advantage of this technology of absorber is the perspective to adjust independently the device parameters (mass, nonlinear stiffness and damping) according to the operational conditions. To achieve this purpose, quasi-static and dynamic tests have been performed on three types of commercial devices (one with structural modifications), in order to define the constructive characteristics that it should present. An experimental setup has been developed using a one-dimensional acoustic linear system coupled through a box (acting as a weak spring) to a loudspeaker used as a suspended piston acting as an essentially nonlinear oscillator. The tests carried out on the whole vibro-acoustic system have showed the occurrence of the acoustic TET from the acoustic media to the suspended piston and demonstrated the efficiency of this new kind of absorber at low frequencies over a wide frequency range. Moreover, the experimental analyses conducted with different NES masses have confirmed that it is possible to optimize the noise absorption with respect to the excitation level of the acoustic resonator.

Mots clés: Targeted Energy Transfer; tuned acoustic absorber; nonlinear

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Riccardo Mariani, Sergio Bellizzi, Bruno Cochelin, Philippe Herzog, Pierre-Olivier Mattei. Toward an adjustable nonlinear low frequency acoustic absorber. Journal of Sound and Vibration, 2011, 330 (22), pp.5245-5258. ⟨10.1016/j.jsv.2011.03.034⟩. ⟨hal-00628729⟩