Free vibration of thin-walled composite beams with I-shaped cross-sections

A general analytical model applicable to the dynamic behavior of a thin-walled I-section composite is developed. This model is based on the classical lamination theory, and accounts for the coupling of flexural and torsional modes for arbitrary laminate stacking sequence configuration, i.e. unsymmetric as well as symmetric, and various boundary conditions. A displacement-based one-dimensional finite element model is developed to predict natural frequencies and corresponding vibration modes for a thin-walled composite beam. Equations of motion are derived from Hamiltonʹs principle. Numerical results are obtained for thin-walled composites addressing the effects of fiber angle, modulus ratio, height-to-thickness ratio, and boundary conditions on the vibration frequencies and mode shapes of the composites.