Reference Type:  Journal Article
Record Number: 1
Author: Yang, C., Yu, Z. X., Sun, Y. P., Zhao , L. and Zhao, H.
Year: 2017
Title: Axial residual capacity of circular concrete-filled steel tube stub columns considering local buckling
Journal: Advanced Steel Construction
Volume: 14
Issue: 3
Pages: 18
Start Page: 496
Short Title: Axial residual capacity of circular concrete-filled steel tube stub columns considering local buckling
DOI: 10.18057/IJASC.2018.14.3.11
Keywords: CFST, stub column, circular section, axial residual capacity, superposition method, local buckling
Abstract: This paper proposes a superposition method considering local buckling to estimate the residual capacity of circular concrete-filled steel tube stub columns (CFSTs) under axial compression based on substantial experimental data, consisting of 3 recently conducted tests as well as 150 test results from available literature. The proposed approach accounts for the influence of local buckling of the steel tube on confining effect, by introducing a coefficient to reduce the compressive strength of concrete in the post-buckling stage. Three specimens, including a bare steel stub column with circular hollow section (CHS), a CHS with concrete restraint and a CFSTs, were tested to investigate the contribution of concrete on the local buckling. Further, the mechanical model of steel tube was established and the design equations for residual bearing capacity of the tube were derived. The nominal load-shortening curves of the concrete core are extracted from 150 collected experimental curves of the CFSTs, with different parameters such as diameter-to-thickness (D/t) ratio, yield strength fsy and concrete strength fcp. The variation of the stiffness degradation in the curves indicates that the effect of local buckling on both ductility and residual compressive strength of the concrete core are correlated with the section type of the steel tube. The residual compressive strength decreases exponentially with the increase of the generalized outer diameter-to-thickness ratio.
Author Address: School of Civil Engineering, Southwest Jiaotong University, Chengdu, China