Free and Random Forced Vibration Analysis of Spherical Sandwich Shells

Abstract

This paper presents a detailed analysis of the free and random vibrations of an all-side-clamped spherical sandwich shell. The sandwich is composed of graphite-epoxy layers, each consisting of four laminas with different fiber orientations and an isotropicKevlar 29 core layer. The study employs the First-Order Shear Deformation Theory (FSDT) to establish kinematic relations and Hamilton’s principle to derive the equations of motion. The sandwich shell is discretized,and equations of motion are reduced to algebraicequationsusing the Differential Quadrature Method (DQM). Natural frequencies are found and subsequently, the GeneralizedAlpha Method is applied to solve the random forced vibration problem. To validate the accuracy of the results, a comparison is made with solutions obtained using the ABAQUS software.

Keywords

• spherical sandwich shell
• differential quadrature method (dqm)
• free vibration
• random vibration
• first order shear deformation theory (fsdt)
• generalized alpha method