Application of piezoelectric macro-fiber-composite actuators for the suppression of noise transmission through curved glass plates

An investigation on the application of the piezoelectric Macro-Fiber-Composite (MFC) actuators for the suppression of the noise transmission through the curved glass plates is presented. It is known that when the incident sound wave in the air hits the glass plate or curved plate or shell, part of the acoustic wave is reflected, which makes the plate vibrate, and part of the wave is transmitted. It is easy to understand that the higher the flexural rigidity of the glass plate the bigger part of the acoustic sound wave is reflected than transmitted. This simple physical phenomenon can be profitably used for the suppression of the noise transmission through glass plates. The noise suppression effect is achieved using the MFC actuator, which is attached to the vibrating glass plate. When the piezoelectric MFC actuator is shunted by the active electronic circuit, which has a negative capacitance, it is possible to greatly suppress the vibration of the glass plate and also the noise transmission through the glass plate. The sound shielding efficiency of the glass plate is measured by the acoustic transmission loss (TL), which is expresed in decibel scale. If the amplitude of the window vibrations decreases, the value of TL increases. The effect of the glass plate geometry, and the electrical properties of the active shunt circuit on the enhancement of TL is analyzed using Finite Element Method numerical simulations. The comparison of the results of numerical simulations with acoustic measurements is presented. The possibility of the use of this method for the suppression of the noise transmission through the glass window plates is discussed.