A vibro-acoustic coupling modeling method for coplanar built-up plates

Abstract

Coplanar built-up plates coupled by plate elements have wide applicability in engineering fields. Their diverse geometries pose a challenge to vibro-acoustic coupling modeling. Therefore, a discrete collocation point method is proposed for the first time to establish a semi-analytical vibro-acoustic coupling model for such structures. Based on the infinitely rigid baffle assumption, one side of coplanar built-up plates is in contact with a semi-infinite heavy fluid domain. Motivated by the element discretization, the coplanar built-up plates are discretized into several elements, the boundary conditions and coupling conditions are implemented using virtual springs. All energy expressions are derived via the first-order shear deformation theory. When considering the sound pressure loading effect, the vibration and acoustic fields of each element are expanded in Chebyshev polynomials. Relying on sound pressure continuity, the vibro-acoustic coupling relationships among the elements are established. Finally, a complete vibro-acoustic coupling equation is derived using the Rayleigh-Ritz method. This paper takes cross-shaped, T-shaped, Z-shaped and L-shaped built-up plates as examples to validate the convergence and accuracy of the proposed method. Furthermore, the underwater vibro-acoustic characteristics of the above-mentioned structures are analyzed. This work is expected to be a valuable and dependable reference for future research of such structures.