Structural and acoustic responses of beams and plates considering various damping techniques

Acoustic responses to vibrations of beam and plate models considering various structural and acoustic damping techniques are investigated. Variational formulation methods are used for developing structural governing equations. Structural damping mechanisms such as tuned mass absorbers, structural damping and constrained layer damping are included in the beam and plate vibration analyses. For the beam model, structural beam frequency responses are incorporated into a two dimensional acoustic cavity response calculation as vibrating boundary conditions. Sound absorbing materials are also implemented in the two dimensional acoustic response calculations. In situ transmission loss measurements with the plate models are obtained by measuring acoustic pressure difference on both sides of the plate models under plane wave excitation. Analytical vibration amplitudes of the plate models are correlated with the experimental measurements by comparing changes in in situ transmission losses obtained with the measured acoustic pressure levels and structural analytic vibration levels at structural resonant frequencies. Good correlation is found between experimental measurements and analytical results at these frequencies.