Local buckling, post-buckling and collapse of thin-walled channel section composite columns subjected to quasi-static compression

A post-buckling behaviour analysis and an ultimate load estimation of thin-walled composite channel columns under a constant rate of end shortening are presented. The columns with C-sections were made of a carbon-epoxy composite - a laminate consisting of eight symmetrically oriented plies. Four different layer arrangements were taken into consideration. The main objective of the study was to investigate the behaviour of the considered columns under quasi-static compression to achieve their collapse. The experimental tests were performed under standard conditions on a universal ZWICK Z100 testing machine. To collect the experimental data, strain gauges for strain measurements, a laser gauge for deflections and acoustic emission testing equipment were employed. A numerical analysis was conducted with the Abaqus commercial FEM software package. The experimental results were then used to develop FEM models that allowed one to describe the post-buckling behaviour and to estimate the ultimate load-carrying capacity of the composite channels under investigation.