FINITE-ELEMENT VIBRATION ANALYSIS OF A HELICALLY WOUND TUBULAR AND LAMINATED COMPOSITE-MATERIAL BEAM

Finite element stiffness and consistent mass matrices are derived for helically wound, symmetrical composite tubes. The tubular element is c onsidered to have constant cross-section and small deformations restri cted to a plane. Each node has three degrees of freedom: axial and tra nsverse displacement and rotation (slope of transverse displacement). Shell theory and lamination theory are used to formulate element stiff ness matrices. The stiffness and mass matrices derived from the helica lly wound tubular composite material are reduced to symmetrically lami nated composite beam. The free vibration and natural frequency are inv estigated for five different materials: steel, aluminum, carbon/N5280, Kevlar-49/epoxy and graphite/epoxy composites and various layup confi gurations. One application of a rotating flexible beam is investigated . The dynamic model of the flexible rotating beam includes the coupled effect between the rigid body motion and the flexible motion. The inv erse dynamic simulation is performed by a prescribed driving torque in the numerical simulation. The influence of flexibility on rigid body motion are presented and discussed. From the numerical results, the co mposite material strongly possesses the lower power consumption and th e passive control in damping the vibration of the structure.