Measurements of wave propagation characteristics of sandwich structures damped by viscoelastic core materials

Abstract

Experimental methods to measure frequency-dependent dynamic properties of sandwich structures are proposed. Flexural wave propagations are analyzed using the compressional beam theory. Using the assumed wave functions, the wavenumbers are measured through the transfer function method requiring small number of vibration measurements. Different types of core materials such as lightweight foam and rubber material were used in the experiments and their capabilities in reducing the vibration and consequently sound radiation was investigated. Using the proposed method, the mechanism of vibration damping of the core is analyzed.