Nonlinear free flexural vibrations/post-buckling analysis of laminated orthotropic beams/columns on a two parameter elastic foundation

Nonlinear free flexural vibrations and post-buckling of laminated orthotrop ic beams resting on a class of two parameter elastic foundation are studied using a three-noded sheer flexible beam element. Geometric nonlinearity is considered using von Karman's strain-displacement relations. The formulati on includes the effects of transverse shear deformation, in-plane and rotar y inertia terms. Exact numerical integration is employed for evaluating all the strain energy terms. The nonlinear governing equations are solved by e mploying the direct iteration technique. Numerical results are obtained for orthotropic and cross-ply laminated beams with simply supported boundary c onditions. A detailed study is carried out to highlight the influences of d ifferent parameters on frequencies and buckling loads of laminated orthotro pic beams. (C) 1999 Elsevier Science Ltd. All rights reserved.