Coupled Free Vibrations Of Tapered Box-Beams Made Of Composite Materials.

Abstract

In this paper, analytical solutions are developed for the free vibration analysis of tapered thin-walled laminated-composite beams with closed cross-sections. The present approach is based in a recently developed model that incorporates in a full form the shear flexibility. The model considers shear flexibility due to bending as well as non-uniform torsional warping. The model is briefly reviewed with the aim to present the equilibrium equations and the related boundary conditions and constitutive equations. The lamination can be selected in order to manifest different types of elastic couplings. The typical laminations for a box-beam, like Circumferentially Uniform Stiffness and Circumferentially Asymmetric Stiffness stacking sequences, are analyzed.
The exact values (i.e. with arbitrary precision) of frequencies are obtained by means of power series schemes. A parametric analysis is performed for different taper ratios, stacking sequences and materials.