Improvement of Transmission Loss Using Active Control with Virtual Modal Mass

Abstract EN

This paper deals with an alternative modal active control approach to reduce sound transmission through a structure excited by an acoustic wave.

Active control makes it possible to conserve lightness while improving acoustic performances.

“Modal mass damping control” is proposed for light and small structures having slight modal overlap.

The aim of this control is to modify the modal distribution of high radiation efficiency modes with active modal virtual mass and active modal damping.

The active virtual mass effects lower eigen frequencies to less audible frequency range while reducing vibration amplitudes in a broad frequency range.

An application of this concept is presented in a simple smart structure.

It is harmonically excited on large bandwidth by a normal acoustic plane wave.

Results obtained by active modal virtual mass and damping control are compared to other modal control approaches.