AA Refined Model For Eigenfrequency Analysis OfThin And Thick Composite Beam Structures

Abstract

A higher order shear deformation theory, assuming a non-linear variation for the displacement field, is used to develop a finite element model to predict static and free vibration behaviour of anisotropic multilaminated thick and thin beams, which are currently used in ship design. The model is based on a single-layer Lagrangean four-node straight beam element with fourteen degrees of freedom per node. It considers bending into two orthogonal planes, stretching and twisting. The most common cross section and symmetric and non symmetric layups are studied. The behaviour of the model is tested on thin and thick isotropic and composite beams. Comparisons show that the model is accurate and versatile. The good performance of the present model is evident on the prediction of the fundamental and higher modes natural frequencies of thin and thick highly anisotropic beam structures. Several applications are shown and discussed.