Natural frequency characteristics of thin-walled homogeneous and manifold layered cylindrical shells under pressure using energy method

Abstract

Energy method for the vibration of two types of cylindrical shells, namely thin-walled homogeneous isotropic and manifold layered isotropic cylindrical shells under uniform external lateral pressure is presented. The study is carried out based on strain-displacement relationship from Love’s shell theory with beam functions as axial modal function. A manifold layered cylindrical shell configuration is formed by three layers of isotropic material where the inner and outer layers are stainless steel and the middle layer is aluminum. The homogeneous cylindrical shell is made-up of isotropic one layer with stainless steel. The governing equations with uniform external lateral pressure for homogeneous isotropic and manifold layered isotropic cylindrical shells are obtained using energy functional by the Lagrangian function with Rayleigh-Ritz method. The boundary conditions that are presented at the end conditions of the cylindrical shell are simply supported-simply supported, clamped-clamped and free-free. The influences of uniform external lateral pressure and symmetrical boundary conditions on the natural frequency characteristics for both homogeneous and manifold layered isotropic cylindrical shells are examined. For all boundary conditions considered, the natural frequency of both cylindrical shells with symmetric uniform lateral pressure increases as h/R ratio increases and those considering natural frequency of the both cylindrical shells with symmetric uniform lateral pressure decrease as L/R ratio increases.