Buckling and limit states of thin-walled composite columns under eccentric load

The objective of this study was to investigate the influence of eccentric compressive load on the buckling, post-buckling and load-carrying capacity of thin-walled top-hat cross-section composite columns. The CFRP columns were manufactured by the autoclave technique. The scope of the study involved performing experimental tests on real structures as well as numerical calculations by the finite element method. The experimental tests were conducted in the full range of loading, until the structure's failure. Post-buckling equilibrium paths and acoustic emission signals were measured in order to determine actual condition of the composite material. Nonlinear FEM calculations were made by the progressive damage criterion, in which the damage initiation of the composite material was estimated based on Hashin's theory, whereas damage evolution was described by the energy criterion. The numerical simulations were performed using the commercial software ABAQUS (R). The numerical results were in good agreement with the experimental results obtained for real structures. The results demonstrated a significant influence of eccentric compressive load on the buckling and post-buckling characteristics of the tested structures.