Post-buckling and limit states of composite channel-section profiles under eccentric compression

Abstract

This paper presents results of study investigating the post-buckling and limit states of compressed thin-walled composite channel-section profiles. Both experimental and numerical methods were used. The primary objective of experiments was to determine the post-buckling characteristics of real structures subjected to compression over the full range of loading until final failure. The experiments involved axial and non-axial compression of the C-profiles with different stacking sequences of plies, fabricated by autoclaving. The effects of eccentric load and ply stacking sequence on the non-linear stability and load-carrying capacity of the compressed structures were investigated. Numerical analysis was performed by the finite element method and it involved solving the problem of non-linear stability of the compressed thin-walled structures. The purpose of the analysis was to develop experimentally verified numerical models enabling the description of the structure's behaviour in the post-buckling range, including the moment of load-carrying capacity loss. A progressive damage model was used to assess the extent of damage in the composite material. The nonlinear calculations were made by the Newton-Raphson method using the commercial simulation software ABAQUS®.