Experimental Study of Sound Transmission Loss in Electrorheological Liquids

Abstract

Electrorheological (ER) liquids possess the ability to change their physical properties like the apparent viscosity and modulus of elasticity under the influence of an external electric field. They serve successfully in the field of active vibration control—as well as in many other areas. In the Acoustic Laboratory at the College of Engineering, Southern Illinois University in Carbondale, research on the possibility of applying ER liquids to the control of a sound transmission loss (STL) was conducted. The STL was investigated for various kinds of ER suspensions in the frequency range 100 Hz to 2 kHz. An influence of the electric field density on the STL was different for normal and shear stress developed by DC voltage. In both cases the STL decreased with the increasing electric field density. These properties could be potentially useful in sound propagation control applications.