Free Vibration of Metallic and Composite Beams Exhibiting Bending-Torsion Coupling

摘要

This paper is concerned with a detailed investigation of free vibration characteristics of metallic as well as composite beams exhibiting bending-torsion coupling. Of particular interest, is the effect of two different types of coupling between bending and torsional deformations as prevalent in metallic and composite constructions, respectively. In the former the coupling occurs as a result of non-coincident mass and shear centres. By contrast, mode coupling for the composite beams is principally due to ply orientation and anisotropic nature of fibrous composites. Thus for metallic beams it is primarily the inertial coupling that combines bending and torsional deformations and this coupling vanishes completely for static problems. However, for composite beams bending-torsion coupling is inherent in static as well as in dynamic problems. In this paper, results are obtained for both metallic and composite beams and they are compared and contrasted. The principal parameters of these two types of beams, which influence the results, are varied and their subsequent effects on modal characteristics are studied. Finally some conclusions are drawn. The investigation is aimed at laying the foundation for further research in aeroelastic behaviour of metallic and composite wings, and it is in this context, the results and conclusions are expected to be most useful.