An analytical study of the effects of a circumferentially corrugated core on sound transmission through double-walled cylindrical shells

Corrugated structures are widely being used in industrial applications, which raises the demand for careful analysis of their behavior. To fill the gap for vibroacoustic characteristics, this paper focuses on proposing a model to investigate sound transmission through double-walled cylindrical shells with a circumferentially corrugated core. The structure is composed of outer and inner isotropic layers and a corrugated core. The outer layer is subjected to an oblige plane wave, and also a subsonic flow is traveling outside the double-walled shell. An equivalent method is applied to replace the corrugated core as axial, radial, and rotational springs with specific stiffness coefficients. The first-order shear deformation theory (FSDT) is applied to describe the behavior of isotropic shells. A considerable parametric study is established concerning both the incident wave and structural characteristics. The results show that the presence of the corrugated core improves sound transmission loss (STL) of the structure in the mass-controlled region, and it has a negative effect on STL in the coincidence-controlled region; therefore, using such a core for sound insulation depends on the desired frequency domain.