Local and global vibration of thin-walled members subjected to compression and non-uniform bending

The local-plate, distortional and global vibration behaviour of thin-walled steel channel members subjected to compression and/or non-uniform bending is studied. This investigation is carried out by means of a very recently developed Generalised Beam Theory (GBT) formulation, which takes into account the geometrically nonlinear stiffness reduction caused by the presence of (i) longitudinal stress gradients and (ii) the ensuing shear stresses. Taking advantage of the GBT modal features, one analyses the effect of the applied load and bending moment gradient on the small amplitude vibration behaviour of the loaded members (beam-columns). For validation purposes, some GBT-based results are compared with values yielded by either shell finite element analyses, performed in commercial codes, or experimental results available in the literature.