Free vibration analysis of functionally graded sandwich spherical shells with honeycomb core resting on Kerr foundation using the MITC4 element

Abstract

ABSTRACT The main object of this paper is to further extend the MITC4 element to analyse the free vibration of FG sandwich spherical shells with a honeycomb core (so-called h-FGSS shells) resting on Kerr foundation (KF). The MITC4 originates from a three-dimensional continuum description degenerated to shell behaviour which can be applied to both thick and thin shells. The h-FGSS shell consists of an inner honeycomb core and two different FG skin layers. FSDT is used due to its simplicity and efficiency. The KF includes three parameters as upper springer stiffness ( k U ), upper springer stiffness ( k L ), and the shear layer stiffness ( k S ). The performance and accuracy of the present formulation are verified through comparative examples. Furthermore, the numerical and graphical results show a general picture of the influence of the input parameters on the free vibration of h-FGSS shells, especially the geometrical parameters of the honeycomb core.