Erratum: “Experimental Investigation of Reduced Beam Section Moment Connections without Continuity Plates” [Earthquake Spectra 20, 1185–1209 (2004)]

2007 ◽  
Vol 23 (1) ◽  
pp. 261-261
Author(s):  
Chris P. Pantelides ◽  
Yasuteru Okahashi ◽  
Lawrence D. Reaveley
2004 ◽  
Vol 20 (4) ◽  
pp. 1185-1209 ◽  
Author(s):  
Chris P. Pantelides ◽  
Yasuteru Okahashi ◽  
Lawrence D. Reaveley

The AISC 2002 Seismic Provisions for Structural Steel Buildings recommend that usage and sizing of beam flange continuity plates across the column web shall be based on tests. The Recommended Seismic Design Criteria for New Steel Moment-Frame Buildings ( FEMA-350) state that unless project-specific testing is performed to demonstrate that continuity plates are not required, moment-resisting connections should be provided with continuity plates when the thickness of the column flange is below a minimum value. One of the preferred moment connections for seismic-resistant steel frames is the reduced beam section (RBS) moment connection, which has performed well under cyclic loads in laboratory testing. To demonstrate the effectiveness of the RBS moment connection without continuity plates in the panel zone, a series of four full-scale tests of exterior beam-column connections was carried out. All materials were A572 Grade 50 steel; the beams were W30×132, two of the assemblies used W14×283 columns, and the other two used W18×211 columns. The beams were welded to the columns using complete joint-penetration welds. All four tests demonstrated that the RBS connections without continuity plates developed a total interstory drift angle greater than 0.04 radians and met the requirements for special moment frames.


2018 ◽  
Vol 4 (6) ◽  
pp. 1240 ◽  
Author(s):  
Christos Sofias ◽  
Dimitra Tzourmakliotou

Reduced Beam Section (RBS) moment resisting connections are among the most economical and practical rigid steel connections developed in the aftermath of the 1994 Northridge and the 1995 Kobe earthquakes. Although the RBS connection effectiveness was widely investigated using US design and construction practices, only limited data exist from European research. Recommendations of RBS applications in steel frames were prescribed in EC8, Part3. However the reliability of these recommendations is under consideration due to above mentioned poor existing data. This paper examines numerous different contours of radius cut-out (Group A) and provides recommendations for the design and detailing of radius cut Reduced Beam Section (RBS) moment connections.  Furthermore, it examines and compares different beam cross sections of European steel profiles (Group B) while the sizing of the RBS cut is kept at a constant ratio. Analytical approach was conducted investigating the adopted by EC8, Part 3 key parameters for the design. The main objective of the applied RBS geometry is to protect the connection and its components (endplate, column flange, bolts, welds) from either plastification or failure. Although the computational cost for optimization with ABAQUS is very large, the results of this study ensures on one hand that the performances of the structural parts can be effectively improved by shape optimization and an the other hand that adjustment in the geometry of the radius cut is needed for safe application to European profiles.


2010 ◽  
Vol 136 (9) ◽  
pp. 1140-1150 ◽  
Author(s):  
Dimitrios G. Lignos ◽  
Dimitrios Kolios ◽  
Eduardo Miranda

2007 ◽  
Vol 34 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Sang-Hoon Oh ◽  
Young-Ju Kim ◽  
Tae-Sup Moon

This study investigated the effectiveness of retrofit methods in improving the deformation capacity of existing moment connections in composite beams. Nonlinear finite element analysis was also performed to identify the cause of the connection failure prior to testing. Tests included one conventional specimen and four retrofit specimens. Three retrofit methods were introduced: a reduced beam section (RBS) only, an RBS with bottom flange reinforcement (RBR), and an RBS-shaped bottom flange reinforcement (RSR). A composite beam performs differently than a bare steel shape because the concrete compression flange greatly increases the tensile demands on an unreinforced bottom flange. Therefore, these retrofit methods were applied only to the bottom flanges of the beam. Quasi-static loading tests were performed. The main conclusions were as follows: (i) the deformation capacity of the existing moment connections in composite beams is not sufficiently improved by RBS alone; and (ii) both the RBR and RSR details move the plastic hinge away from the face of the column and reduce stress levels in the vicinity of the beam bottom flanges, sufficiently improving the deformation capacity.Key words: composite construction, seismic performance, reduced beam section (RBS), flange reinforcement, ductility, deformation capacity.


2007 ◽  
Vol 348-349 ◽  
pp. 717-720
Author(s):  
Ki Hoon Moon ◽  
Sang Whan Han ◽  
Ji Eun Jung

Reduced Beam Section (RBS) moment connections are developed for Special Moment Resisting Frames (SMRF). According to the beam web attachment the column flange RBS connections are classified into Reduced Beam Section with Bolted web connections (RBS-B), and the Reduced Beam Section with Welded web connections (RBS-W). Beam flanges are welded to the column. Regardless of different web attachment details in RBS-B and RBS-W connections current design procedures (FEMA 350) assumes that they could develop plastic moment of the beam gross section. In current design procedures, RBS-B connections should provide the sufficient strength that can reach the plastic moment capacity of the connected beam. However, some experimental researches reported that the beams in RBS-B connections fractured before the connection reached its plastic moment capacity. Such undesirable fracture shows that RBS-B connections have less strength than RBS-W connections. And if RBS-B connections designed in current design procedures, it might fail in a brittle manner and not satisfy SMRF due to undesirable fracture. Thus, this study develops a new set of equations for accurately computing the moment strength of RBS-B connections. The proposed strength equation accurately predicts connection moment capacity for RBS-B connections.


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