The transmission loss through curved sandwich composite structures

The principal aim of this work is to present a model for the transmission loss of sandwich composite cylindrical shells. The effects of membrane, bending, and transverse shearing as well as rotational inertia are considered in all of the layers composing the structure. The elastic constants of any layer are related to the orthotropic angle‐ply defined as the angle of the principal directions of the layers material to the global axis of the shell. Fundamental relations are expressed using the dynamic equilibrium relations of the unit forces in the structure. The structural impedance, critical frequencies and ring frequency are computed numerically in the general case of symmetrical laminated composite shell. Their expressions are developed in a wave approach context. A general eigenvalue approach to compute the dispersion curves of such structures is presented. Using these curves, the radiation efficiency, the modal density, the group velocity an the resonant and nonresonant transmission loss are computed ...