A simplified method for determining the damping loss factor of panels using a narrow band decay method

This paper presents a damping loss factor estimation method for structures made of solid elastic and viscoelastic materials. Using an impulsive excitation signal, an acceleration impulse response of the panel in free edge boundary conditions is measured and the damping loss factor is determined at each frequency of interest, by applying an overlapped narrow band frequency decay method. This means that, for the duration of the impulse, the decay of each frequency band is measured in time domain and, using a backward integration approach, structural reverberation time is determined. Successively, the damping loss factor is calculated using a well-established relationship between measured quantities and frequencies. Firstly, several investigations related to the post-processing procedures for the determination of structural reverberation time will be analyzed in detail. Results will then be presented and discussed for different structures and compared with different available measurement techniques. (C) 2017 Institute of Noise Control Engineering.