Sound transmission loss in piezoelectric intelligent composite cylindrical shells under sound waves

In this study, it is assumed that the outer shell of the sandwich has a core made of functional calibrated materials with piezoelectric patches and the inner shell is made of layered composites. Double-walled cylindrical shells have three external, internal and middle acoustic environments and are exposed to acoustic waves with a specific angle of effect. The dynamic equations of the structure are derived using the hypothesis of first-order shear displacement field of shells and Hamilton principle and together with the fluid / structure boundary conditions form the final equations. Using the Fourier series expansions of the input, return, and output sound pressures and shell displacements, the dynamic equations are discretized to form a state matrix. After validating the results with existing articles, finally the effects, voltage applied by piezoelectric patches, percentage of functional materials, angle of fibers used in composites, types of composite materials, number of piezoelectric patches and angle of impact on the structure of sound transmission behavior It has been evaluated in a certain frequency range. Finally, the voltage parameters applied by the piezoelectric patches, the percentage of functional materials, the angle of the fibers used in the composites, the types of composite materials, the number of piezoelectric patches and the angle of impact increased the sound loss.