On buckling collapse and failure analysis of thin-walled composite lipped-channel columns subjected to uniaxial compression

• The obtained results showed both qualitative and quantitative conformity of ultimate load found by numerical calculations with experimental outcomes.
• The results allowed to estimate the influence of the composite׳s ply sequence on the value of ultimate load.
• The results of the non-linear analysis of a post-buckling state, when the compressive load did not exceed 150% of the buckling load, were convergent for the different variants of boundary conditions modeling. Significant discrepancies of the numerical results were, however, observed for far post-buckling and collapse states. The numerical results for the full load range demonstrate that the designed models were substantially sensitive to variations regarding the way of supporting ends of the columns being compressed.

The paper deals with buckling of short thin-walled lipped-channel columns, simply supported on both ends and subjected to uniformly distributed compressive load. The main objective of the study was to investigate the structure׳s work in far post-buckling state and at collapse corresponding to the moment of the column׳s stiffness loss. The following measuring devices and methods were applied: electrical strain gauges for strain measurements, a laser sensor to measure the displacements, and the Acoustic Emission method. Along with running the experimental tests, the non-linear stability of compressed composite columns was analyzed with the Finite Element Method. The numerical and experimental results showed good agreement.