Effect of accidental joint eccentricity on the performance of concentric steel braces


Sannah N., Demir S., Soalih H.

3RD INTERNATIONAL CIVIL ENGINEERING & ARCHITECTURE CONFERENCE , Trabzon, Turkey, 12 - 14 October 2023, vol.1, no.1, pp.1380-1390

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • Doi Number: 10.31462/icearc.2023.sme452
  • City: Trabzon
  • Country: Turkey
  • Page Numbers: pp.1380-1390
  • Karadeniz Technical University Affiliated: Yes

Abstract

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.