Dynamic stiffness analysis for free vibrations of axially loaded laminated composite beams

The free vibration and buckling behaviors of axially loaded laminated composite beams having arbitrary lay-up are investigated by using the dynamic stiffness method. The influences of axial force, Poisson effect, axial deformation, shear deformation and rotary inertia are taken into account in the formulation. The exact dynamic stiffness matrix is developed by directly solving the governing differential equations of axially loaded laminated beam in free vibration. The application of the dynamic stiffness matrix is illustrated by particular composite beams for which some comparative results are available in the literature. The effects of axial force and boundary condition on the natural frequencies, buckling loads and/or mode shapes of the laminated beams are demonstrated.