Buckling and vibration analysis of functionally graded composite structures using the finite element method

The authors [Oyekoya OO, Mba DU, El-Zafrany AM. Structural integrity of functionally graded composite structure using Mindlin-type finite elements. ICCES 2008;172(1): 1–6] have previously written a paper on structural integrity of functionally graded composite (FGC) structure using Mindlin-type finite elements. In this paper, the Mindlin-type element and Reissner-type element have been further developed for the modelling of FGC plate subjected to buckling and free vibration. The Mindlin-type element formulation is based on averaging of transverse shear distribution over plate thickness using Lagrangian interpolation. The Reissner-type element formulation is based on parabolic transverse shear distribution over plate thickness using Lagrangian and Hermitian interpolation. The composite plate considered in this paper is functionally graded in the longitudinal direction only, but the FE code developed is capable of analysing composite plates with functional gradation in transverse and radial direction as well. This study was able to show that the structural integrity enhancement and strength maximisation of composite structures are achievable through functional gradation of material properties over the structure.