Sound Transmission Loss of a cylindrical shell made of functionally graded materials with piezoelectric patches

In this study, sound transmission loss of a cylindrical shell made out of functionally graded materials with an arrangement of piezoelectric patches is investigated in the framework of the first-order shear deformation theory. Also, power law model is utilized to take into account material characteristics distribution along the thickness of the shell. It is noteworthy that both outer and inner piezoelectric patches are used as actuator and sensor. The structure is immersed in an acoustic medium of air and is subjected to acoustic waves with certain incident angle. The derivation of vibroacoustic equations in the form of coupled relations is realized by implementing Hamilton’s principle in conjunction with fluid/structure compatibility conditions. An analytical method is exploited to solve the coupled vibroacoustic governing equations with Fourier series. After validation study, parameter studies reveal the effects of the functionally graded index, incident angles, external electric voltage, and characteristics of piezoelectric patches on the sound transmission loss behavior of the structure in a certain frequency domain. Results indicated that with increasing the power law index, sound transmission loss decreases in the low-frequency region. Also, the applied voltage is able to improve the sound transmission loss especially in high-frequency region.