3RD INTERNATIONAL CIVIL ENGINEERING & ARCHITECTURE CONFERENCE , Trabzon, Turkey, 12 - 14 October 2023, vol.1, no.1, pp.1380-1390
Purpose: In AISC 360-22 and Eurocode 3, certain safety factors applied to consider uncertainties related to initial
imperfections of concentric braces. However, these safety factors are the same for each slenderness ratio, and it is not
known up to which eccentricity level they provide a safe result. In this study, it is aimed to investigate the cyclic
performance of steel braces under low eccentric loading, for better understanding and representation of their buckling
strength, failure modes and post buckling behavior, for design and evaluation purposes.
Study design/methodology/approach: An experimental program was carried out to examine the effect of various
accidental joint eccentricity conditions. Four sets of specimens, totaling twelve steel brace specimens, were designed.
For the brace specimens, four different circular hollow sections were used to represent a range of global slenderness.
All specimens were tested under displacement controlled quasi-static cyclic loading.
Findings: The effect of eccentricity on the buckling strength of braces varies depending on the slenderness ratio. For
brace members with a dimensionless slenderness ratio of less than 1.5, the buckling strength decreases, while for
members with a slenderness ratio greater than 1.5, the buckling strength does not significantly change.
Originality/value: In order to restrict accidental joint eccentricity, reasonable alignment tolerances for concentric braces
should be defined in ANSI/AISC 303-22 (2022) and EN 1090-2 (2018). On the other hand, the safety factor, which
takes into account the initial imperfections, may also change depending on the slenderness ratios.