Experimental and numerical study on eccentrically compression-loaded cold-formed flat oval-perforated steel square hollow-section stub columns

This study addressed a notable gap in the literature concerning the behavior of eccentrically perforated hollow-section stub columns under eccentric compression loading. Cold-formed steel square hollow-section (SHS) stub columns with nominal dimensions of 100 mm × 100 mm and a length of 410 mm were experimentally tested. The test results of perforated SHS stub columns with nominal wall thicknesses ranging from 2.00 to 5.00 mm were compared with those of nonperforated specimens. During the experimental stages, the formation and progression of local buckling in all test specimens were observed using the digital image correlation method. Furthermore, a numerical parameter study was carried out, incorporating different eccentricity values in increments of 25 mm from 0 to 100 mm. The research findings showed that when eccentric flat oval-shaped perforations were formed and a column was subjected to eccentric compression loading, the load-bearing capacity substantially reduced by approximately 75 %–78 %. Finite element analysis (FEA) was comprehensively used as a predictive tool to effectively determine both load-bearing capacities and deformation modes of the SHS stub columns. The strong agreement between the FEA predictions and experimental findings demonstrated the reliability of the method for obtaining the behavior of perforated and nonperforated elements under both axial and eccentric compressive loads in terms of the load-bearing capacity and damage mode. Additionally, the effectiveness of a ring-type hole stiffener was numerically investigated by considering different stiffener thicknesses. © 2025 Institution of Structural Engineers