Free vibration analysis of cylindrical honeycomb sandwich panels using state-space Levy method

In the current study, free vibrations of a honeycomb sandwich panel were investigated. The cylindrical sandwich panel consisted of a hexagonal honeycomb core layer and two face sheets. The hexagonal cell honeycomb core was modeled as a solid core made of aluminum according to Gibson's hypothesis. Based on the first order shear deformation shell theory, the coupled governing equations of the panel were derived by using Hamilton's principle. By using the state-space method, the equations were decoupled by shifting the equations from spatial space to modal space and were finally recast in the form of a system of equations. In a free vibration analysis, the roots of the coefficient matrix determinant return the eigenvalues. The validity and accuracy of the current technique were proved by comparing the obtained results with the results of previously published studies. Influences of various geometrical and material parameters and boundary conditions on natural frequencies of the panel were investigated. Numerical examples presented in this study showed that the geometrical parameters of the honeycomb core play a key role in the resulting natural frequencies of the sandwich panel. The results of this paper provide possible benchmark solutions for assessing future works on the free vibration of cylindrical honeycomb sandwich panels and can be relied on for the design of such structures in various engineering applications.