TY - JOUR
T1 - Inelastic cyclic response of RBS connections with jumbo sections
AU - Bompa, D. V.
AU - Elghazouli, A. Y.
AU - Bogdan, T.
AU - Eatherthon, M. R.
AU - Leon, R. T.
N1 - Funding Information:
The financial support from the Research Fund for Coal and Steel of the European Community through the project EQUALJOINTS (Grant agreement no. RFSR-CT-2013-00021), as well as from Virginia Tech, for the experimental assessments in this paper are gratefully acknowledged. The numerical investigations were also supported by the Research Fund for Coal and Steel of the European Community through the project EQUALJOINTS-PLUS (Grant agreement no 754048-2017).
Publisher Copyright:
© 2023 The Authors
PY - 2023/4/15
Y1 - 2023/4/15
N2 - This paper examines the cyclic performance of reduced beam section (RBS) moment connections incorporating larger member sizes than those allowed in the current seismic provisions for prequalified steel connections, through experimentally validated three-dimensional nonlinear numerical assessments. Validations of the adopted nonlinear finite element procedures are carried out against experimental results from two test series, including four full-scale RBS connections comprising large structural members, outside the prequalification limits. After gaining confidence in the ability of the numerical models to predict closely the full inelastic response and failure modes, parametric investigations are undertaken. Particular attention is given to assessing the influence of the RBS-to-column capacity ratio as well as the RBS geometry and location on the overall response. The numerical results and test observations provide a detailed insight into the structural behavior, including strength, ductility, and failure modes of large RBS connections. It is shown that connections which consider sections beyond the code limits, by up to two times the weight or beam depth limits, developed a stable inelastic response characterized by beam flexural yielding and inelastic local buckling. However, connections with very large beam sections, up to three-times the typically prescribed limits, exhibited significant hardening resulting in severe demands at the welds, hence increasing susceptibility to weld fracture and propagation through the column. The findings from this study point to the need, in jumbo sections with thick flanges, for a deeper RBS cut than currently specified in design, to about 66% of the total beam width. This modification would be required to promote a response governed by extensive yielding at the RBS while reducing the excessive strain demands at the beam-to-column welds. Moreover, for connections incorporating relatively deep columns, it is shown that more stringent design requirements need to be followed, combined with appropriate bracing outside the RBS, to avoid out-of-plane rotation.
AB - This paper examines the cyclic performance of reduced beam section (RBS) moment connections incorporating larger member sizes than those allowed in the current seismic provisions for prequalified steel connections, through experimentally validated three-dimensional nonlinear numerical assessments. Validations of the adopted nonlinear finite element procedures are carried out against experimental results from two test series, including four full-scale RBS connections comprising large structural members, outside the prequalification limits. After gaining confidence in the ability of the numerical models to predict closely the full inelastic response and failure modes, parametric investigations are undertaken. Particular attention is given to assessing the influence of the RBS-to-column capacity ratio as well as the RBS geometry and location on the overall response. The numerical results and test observations provide a detailed insight into the structural behavior, including strength, ductility, and failure modes of large RBS connections. It is shown that connections which consider sections beyond the code limits, by up to two times the weight or beam depth limits, developed a stable inelastic response characterized by beam flexural yielding and inelastic local buckling. However, connections with very large beam sections, up to three-times the typically prescribed limits, exhibited significant hardening resulting in severe demands at the welds, hence increasing susceptibility to weld fracture and propagation through the column. The findings from this study point to the need, in jumbo sections with thick flanges, for a deeper RBS cut than currently specified in design, to about 66% of the total beam width. This modification would be required to promote a response governed by extensive yielding at the RBS while reducing the excessive strain demands at the beam-to-column welds. Moreover, for connections incorporating relatively deep columns, it is shown that more stringent design requirements need to be followed, combined with appropriate bracing outside the RBS, to avoid out-of-plane rotation.
KW - Cyclic response
KW - Non-linear analysis
KW - Reduced beam sections
KW - Seismic design
KW - Welded steel connections
UR - http://www.scopus.com/inward/record.url?scp=85148326713&partnerID=8YFLogxK
U2 - 10.1016/j.engstruct.2023.115758
DO - 10.1016/j.engstruct.2023.115758
M3 - Journal article
AN - SCOPUS:85148326713
SN - 0141-0296
VL - 281
JO - Engineering Structures
JF - Engineering Structures
M1 - 115758
ER -