Sound-vibration behaviors of the thin orthotropic rectangular fluid-structure coupled system resting on varying elastic Winkler and Pasternak foundations

This paper establishes a thin orthotropic rectangular fluid-structure coupled system which effectively studies the sound-vibration behaviors. The established coupled system is made up of an acoustic enclosure filled with air or water and a single orthotropic thin plate or parallel double plate on varying elastic Winkler and Pasternak foundations. Based on Fourier series method and classical plate theory (CPT), the admissible functions of the orthotropic plate and cavity could be represented as superposition of the periodic functions. All the unknown series coefficients are gained by the Rayleigh-Ritz method. On the premise of validating the great convergence and accuracy of the established analytical model, both the natural characteristics analysis and the forced response studies under the excitations of a unit monopole source or a unit simple harmonic force are carried out. The effect of various elastic foundations on the fluid-structure coupled system is mainly studied. In addition, some new discoveries have been listed, on the basis of varying orthotropic degrees, boundary constraints and acoustic medium, which could set up the benchmark for the following research.