FINITE-ELEMENT SOLUTION OF NONLINEAR INTRINSIC EQUATIONS FOR CURVED COMPOSITE BEAMS

A geometrically nonlinear finite element analysis, based on a weak for m of the geometrically exact intrinsic equilibrium and constitutive eq uations, is presented for initially curved and twisted composite beams . The resulting nonlinear equations are solved numerically for both no nlinear static deformation and linearized free vibration about the sta tic state of deformation, Results are compared with published exact so lutions for isotropic beams and with recently published experimental d ata for rotating isotropic and composite beams with swept tips. In bot h cases the correlation is excellent. Moreover, the correlation with t he experimental data Is shown to be better than was achieved with a st andard moderate deflection theory, illustrating that a geometrically e xact approach Is needed for general purpose analysis of rotating beams .