A static and dynamic analysis of the postbuckling of geometrically imperfect composite beams

The static and dynamic response of geometrically imperfect composite beams is presented. The proposed model accounts for the midplane stretching of the beam that follows the classical beam theory and its curvature is assumed to be shallow. The assumption of a small strain, moderate deformation is used. The governing equations are nonlinear integral partial-differential equations. A unified approach is used to handle the postbuckling response of composite beams with and without imperfection. As a result, an analytical solution for the beam's static response in terms of the applied axial load, imperfection, and lay up is obtained. Moreover, the free vibrations in the postbuckling domain are investigated. Having the beam's imperfection as a control parameter, the beam's static and dynamic response is investigated and presented. Results show that the imperfection has a significant effect on the static and dynamic response of composite beams.