Free Vibration Analysis of Sandwich Shell

The present work is concerned with free vibration analysis of a three layered doubly curved sandwich shell with viscoelastic core. A finite element model in ANSYS APDL software has been developed for free vibration analysis of the three layer sandwich spherical shell. To validate the ANSYS model natural frequencies of a single layer spherical shell has been compared with those available in literature. The results have been found to be in very good agreement. The natural frequencies of the three layer sandwich shell have been determined using SHELL181 elements. Further modal analysis has been performed on the developed model to analyse the effect of variation of core thickness parameter on natural frequencies under clamped-clamped and simply supported boundary conditions. The experiment analysis has been conducted for both single layer and three layer sandwich shell assuming free-free boundary condition. The experimental results have been found to be in good agreement with the solutions of the finite element method obtained by using ANSYS APDL software