Application of spline element for large-amplitude free vibrations of laminated orthotropic straight/curved beams

Using a cubic B-spline shear flexible curved element, based on the field consistency principle, the nonlinear free flexural vibrations of isotropic/laminated orthotropic straight/curved beams have been studied. The nonlinear governing equations are solved by employing Newmark's numerical integration scheme coupled with modified Newton-Raphson iteration technique. Amplitude-frequency relationships are obtained from the non-linear dynamic response history. Detailed numerical results are presented for various parameters for isotropic and laminated orthotropic beams. The present study brings out the type of non-linearity associated with the curved beams and its dependency on the interaction of curvature with initial amplitude of the beams. (C) 1997 Elsevier Science Ltd. All rights reserved.