Vibro-acoustic analysis of a circumferentially coupled composite laminated annular plate backed by double cylindrical acoustic cavities

The current work focuses on the vibro-acoustic analysis of fluid-structure coupling system composed of a circumferentially coupled composite laminated annular plate and two cylindrical acoustic cavities considering arbitrary acoustic impedance. By employing the unified Ritz energy scheme in conjunction with the first-order shear lamination scheme, the acoustic and structural models in the studied physical system are reasonably established, where the required structural and plate-cavity continuity conditions are taken into account by means of the coupled spring technology and work, respectively. One-dimensional and two-dimensional orthogonal polynomials with the aid of the Fourier harmonic functions are separately applied to construct the variables functions of structural and acoustic domains without meshing requirements. The convergence and correctness of the developed prediction model including various physical parameters are carefully investigated through several comparative examples as well as vibro-acoustic experiment analysis, which illustrates the good insight in the vibro-acoustic mechanism of the studied physical system. Some parametric analysis respecting the effect of structural/acoustic boundaries, cavity depth, coupling radius and material parameter etc. on the coupled vibroacoustic performance is implemented in detail, which may give some guidance for the low-noise pre-design of circumferentially coupled laminated annular plate.