Experimental investigation of channel-section composite profiles’ behavior with various sequences of plies subjected to static compression

This paper deals with the buckling of thin-walled channel-section composite columns subjected to static compression. It was assumed that the columns were supported with articulated joints at both ends. For experimental testing, three series of specimens were manufactured with autoclaving technique. The specimens had identical dimensions but differed about ply sequence. The Hexcel′s HexPly M12 carbon-epoxy prepreg was used in order to fabricate the channel-section profiles. During the stand tests minimal critical forces of the real structure and the corresponding buckling modes were determined with an application of electrical strain gauges. In addition, post-critical equilibrium paths for small overloads—150% of the critical load for the ideal structure—were determined. The experimental results were compared to the ones obtained numerically with the finite element method (FEM).