Improved buckling reduction factors for reclaimed steel members considering imperfections and stresses

This research examines the applicability of previously developed global and local reduction factors to account for the impact of amplified geometrical imperfections and induced stresses on the buckling resistance of slender steel box section columns. In evaluating the suitability of reclaimed steel structures, conducting a resistance check is critical in determining their reusability. In the buckling resistance check, existing geometric imperfections and residual stresses play a significant role, which could stem from (i) the original manufacturing process and (ii) later deformation during its lifetime. Previous investigations studied the effect of the manufacturing process on buckling resistance but did not consider deformations arising during the lifetime. In the current study, the effect of local and global imperfections stemming from deformations at a later time is investigated. The stresses and deformations arising from applied displacements are incorporated into a subsequent analysis to determine the buckling capacity. Previously developed local and global buckling formulas derived from EN1993-1-5 and EN1993-1-1 are evaluated against GMNI analyses that account for the influence of enlarged imperfections and induced stresses. The calibration process is performed by modifying the imperfection factor α in the buckling formulas. Subsequently, the developed formulas are assessed against the interaction buckling resistance of local and global buckling behaviours. This study provides enhanced tools for accurately estimating buckling capacity, particularly in scenarios involving stress formation due to imperfections, thereby improving the accuracy and safety of the application of reclaimed structural members. • Global and local buckling resistances are determined using GMNIA. • The effects of imperfections and their induced stresses are evaluated. • Buckling formulas are calibrated by adjusting the imperfection factor α against GMNIA. • The formulas consider the effect of amplified imperfection and the induced stresses. • The applicability of calibrated formulas for interaction buckling is evaluated.