Vibro-acoustic characteristics of viscoelastic sandwich panel: effect of inherent damping

This paper presents the effect of the inherent material damping of aluminium facings and fibre reinforced polymer (FRP) core composite sandwich panel on vibro-acoustics and sound transmission loss characteristics. The modal strain energy method is used to calculate the modal damping ratio at each mode. To determine the forced vibration response, the harmonic analysis is carried out. From the kinematic continuity of velocity of the structure and the acoustic particle velocity at the surface, the sound power level is calculated. From the results, it is revealed that 19.89 dB of overall sound power level is reduced by including the modal damping ratio in the finite element modeling. Further, it is noticed that by replacing the aluminium plate to aluminium face sheet with an FRP core sandwich panel, the overall sound power level of 11.76 dB and 10.78 dB is reduced based on the same volume and weight analysis respectively.