A semi-analytical method for vibro-acoustic characteristics of orthogonal stiffened laminated cylindrical shells

This paper presents a semi-analytical model for vibro-acoustic characteristics of submerged orthogonal stiffened laminated cylindrical shells strengthened with orthogonal stiffeners. The first-order shear deformation theory (FSDT) combined with the Lekhnitsky smeared stiffener technique is adopted to describe the displacement field, and the spectral boundary element method is utilized to model the sound field. For modeling of a complex stiffened shell, the shell is divided into several main structures with the additional stiffness and mass of the smeared stiffeners. Then, the main structure is separated into sub-segments that match the boundary elements to ensure high accuracy of acoustic calculations. The continuous boundary conditions between sub-segments are simulated by using the artificial spring technique. The Fourier series and Legendre orthogonal polynomials are selected as admissible functions to describe the displacement field and the sound field. The vibration governing equations and Helmholtz integral equation are coupled with each other and solved simultaneously. High accuracy is demonstrated by comparing the results of the developed model with the literature. In numerical investigations, the influences of different external fluids, layup schemes, quantities and shapes of stiffeners (width and height) on vibro-acoustic characteristics of orthogonal stiffened laminated cylindrical shells (OSLCS) are investigated.

Automated summary

This paper proposes a semi-analytical model to describe the vibro-acoustic characteristics of submerged orthogonal stiffened laminated cylindrical shells. The displacement field is described using the first-order shear deformation theory combined with the Lekhnitsky smeared stiffener technique, and the sound field is modeled using the spectral boundary element method. The shell is divided into main structures with additional stiffness and mass of smeared stiffeners, which are further separated into sub-segments to ensure high accuracy of acoustic calculations. The developed model demonstrates high accuracy through comparison with literature, and the influences of different factors on the vibro-acoustic characteristics of orthogonal stiffened laminated cylindrical shells are investigated.