Compressive behaviour of corroded thin-walled circular section steel stub columns

The influences of corrosion on the buckling behaviour and bearing capacity of the circular section steel tubular (CST) stub columns subject to axial compression were investigated experimentally and numerically. Seven CST stub columns with chloride corrosion were investigated. After the accelerated chloride corrosion test on CST stub columns, three methods were used to evaluate the corrosion degree of each specimen. A monotonic axial compression test was then carried out. Based on the test results, the influence of corrosion degree on failure mode, bearing capacity and deformation behaviour were analysed. In addition, the surface morphology of the corroded column was obtained by a 3D Scanner and processed by Geomagic Studio software. Then the reconstructed models were imported into finite element (FE) software ABAQUS. This novel method considering the natural morphology of surface corrosion was verified by comparing the FE solutions to the experimental result. Based on the verified FE model, the deterioration of the mechanical behaviour of corroded compression stub columns under the actual rusty surface was also studied. It was found that the rough surface of the corroded specimens cause non-uniform stress distribution and change buckling mode. Parametric analysis, therefore, was conducted to study the influences of the corrosion degree and steel grade on the yield load. Finally, the proposed design formula is able to predict the axial compression strength of the rusty stub column with reasonable accuracy.

Automated summary

This research experimentally and numerically investigates the influences of corrosion on the buckling behaviour and bearing capacity of circular section steel tubular (CST) stub columns subjected to axial compression. A novel method considering the natural morphology of surface corrosion is proposed and verified. The study also reveals that the rough surface of corroded specimens leads to non-uniform stress distribution and changes in the buckling mode. The proposed design formula can accurately predict the axial compression strength of rusty stub columns.