Mechanical behavior of locally corroded circular concrete-filled steel tubular stubs under local compression

This study used the local compression area ratio ( β ), corrosion depth ratio ( γ t ), corrosion length ratio ( γ L ), and relative corrosion location ( γ s ) as experimental parameters to conduct local compression tests on locally corroded circular concrete-filled steel tubular (CFST) stubs. The experimental results indicate that the failure modes of the specimens include local corroded zone failure, combined failure at the local compression end and the local corroded zone, and local compression end failure. As β increases from 2 to 16, γ t from 0 to 2/3, γ s from 1/4 to 1/2, and γ L from 1/5 to 1/3, the load-bearing capacity of specimens decreases by 41.4 %, 14.3 %, 4.9 %, and 3.2 %, respectively. Additionally, a finite element analysis model, validated by the experimental results, was established to conduct a full-range analysis of a typically locally corroded circular CFST stub under local compression. The analysis results indicate that the stresses in the steel tube and concrete are primarily concentrated at the local compression end and the corroded zones. The concrete bears the majority of the load, with load ratios of 83.2 % – 94.6 % at the compression end and 70.7 % – 87.5 % at the corroded zones. The contact stresses between the steel tube and concrete are mainly concentrated at the edges of the corroded zones and at the local compression end. Finally, based on the parameter analysis and experimental results, simplified formulas for predicting the axial and local compressive load-bearing capacities of locally corroded circular CFST stubs were proposed, with an error range within ±10 %.