Sound and vibration damping materials for aeronautics application

Abstract

This paper deals with the problems of damping of aircraft vibrations, cabin noise as well as thermal insulation. A set of industrially used samples were tested, namely Isodamp C 3000, Fiberform, UGAPOL, Mitaver and Terril 34. Three basic physical characteristics were determined: frequency dependencies of sound absorption coefficient and dynamic modulus of elasticity, thermal conductivity coefficient. Several physical parameters and their frequency dependencies were calculated from measured dynamic modulus of elasticity, i.e. loss factor, insertion loss, and the complex components of the dynamic modulus of elasticity. It was found that material Fiberform is suitable mainly for sound absorption applications, ranging from 400 Hz up to 6000 Hz, where the sound absorption coefficient values were ranging between 0,6 to 0,95. In contrary, the Isodamp C 3000 is suitable mainly for vibration damping applications. This material had several basic resonances at the selected frequencies. The value of dynamic modulus of elasticity was maximum 20 MPa at 2600 Hz frequency. © European Acoustics Association.