VIBRATION OF BUCKLED COMPOSITE THIN-WALLED BEAMS
Patricia N. Dominguez1; Víctor H. Cortínez2; Marcelo T. Piovan2
1 Departamento de Ingeniería, Universidad Nacional del Sur; 2 Centro de Investigaciones en Mecánica Teórica y Aplicada, FRBB, Universidad Tecnológica Nacional
doi:10.20906/CPS/CILAMCE2017-0709
Resumo
Many slender structures employed in several technological situations present non-linear responses in operation conditions. Accordingly, the understanding of different aspects of the non-linear dynamics , such as large amplitudes, natural frequencies dependent of amplitudes or dynamic stability , are of great importance. In particular, the dynamic behaviour of buckled beams has attracted the attention of several researchers. In this connection, there exist interesting applications of post-buckled beams in vibration control devices. In other cases, buckling is an undesired state related with anomalous operation conditions. In order to identify post-buckled states, measurements of natural frequencies may be useful because these values may be correlated with the amplitud of post-buckling displacements. In this work, the vibrations of small amplitud of buckled composite thin-walled beams are analyzed. The corresponding equations of motion are derived from the principle of virtual work. In order to obtain a numerical solution, the finite element method is employed to obtain the modal shapes of the pre-buckled beams. In a second step, the above eigenfunctions are used to approximate the transverse vibrational displacements of the buckled structure. From these approximations and using a global Galerkin approach, the natural frequencies and the corresponding modes of the buckled beams are determined.
Palavras-chave: vibration; thin-walled; buckled beams