Free Damped Vibration of Rotating Truncated Conical Sandwich Shells Using an Improved High-Order Theory

In the present paper, an improved high-order theory is employed to study the free vibration of rotating truncated sandwich conical shells with laminated face sheets and a soft core. The formulation is based on a three-layer sandwich model. First-order shear deformation theory (FSDT) is used for face sheets and quadratic and cubic functions are assumed for transverse and in-plane displacements of the core, respectively. The governing equations of motion are derived according to the Hamilton's principle. Also, continuity conditions of the displacements at the interfaces, as well as transverse flexibility, transverse normal strain and stress of the core have been considered. Analytical solution for free vibration of simply supported sandwich conical shells is presented using Galerkin's method. Effect of some geometrical parameters is also studied on the fundamental frequency of the sandwich shells. Comparison of the present results with those in the literature confirms the accuracy of the proposed theory.