Eccentric compression behavior of stub SCFSTs with local corrosion

This paper investigates the eccentric compression behavior of stub square concrete-filled steel tubes (SCFSTs) with local corrosion. Eccentric compression tests were conducted on 12 specimens, where the rectangular defect was machined to simulate local corrosion damage. The effects of test parameters, including local corrosion dimensions, shape, location, and loading eccentricity on failure modes and load-deformation curves were analyzed. The experimental results revealed that all specimens exhibited similar failure modes characterized by combined local buckling and global bending, with corrosion location and dimensions exerting significant influence on ultimate strength. Through incorporation of hoop confinement degradation caused by local corrosion damage in SCFST, a constitutive model for confined concrete was developed and validated via comparison between finite element simulations and experimental results. Parametric analysis was subsequently conducted to characterize the influence of key parameters on eccentric compression performance of stub SCFSTs with local corrosion. A prediction method for determining the ultimate strength of such members was proposed based on the existing N-M rules, in which the axial compression and flexural strengths were modified with consideration of local corrosion, and the method was validated by the experimental and numerical data pool.