Effects of rib stiffener on vibro-acoustic response of a submerged composite cylindrical shell

Abstract

This study investigates the numerical discretization of wave propagation in a rib-stiffened composite cylindrical shell using Kirchhoff’s theory, accounting for the thinness of the composite layers. The composite shell is subjected to a plane sound wave while immersed in a fluid. A combined numerical simulation, incorporating rotational and tensile springs as well as concentrated masses, is employed to model the mechanical behavior of the stiffeners. The system’s equations of motion are derived using the principle of virtual work, considering the contributions of longitudinal, circumferential, and radial displacements, along with the effects of tensile and rotational springs and concentrated masses. The vibrational equations of the shell are coupled with the fluid equations inside and outside the structure via Euler boundary conditions. The proposed numerical model is validated by comparing the results with previous studies, showing strong agreement. Finally, the effects of key parameters—such as the stiffness, mass, and spacing of the stiffeners—on the shell’s sound transmission are analyzed.