Reduced beam section moment connections subjected to cyclic loading: Experimental analysis and FEM simulation

2009 ◽  
Vol 31 (1) ◽  
pp. 216-223 ◽  
Author(s):  
D.T. Pachoumis ◽  
E.G. Galoussis ◽  
C.N. Kalfas ◽  
A.D. Christitsas
Keyword(s):  
Cyclic Loading ◽  
Experimental Analysis ◽  
Fem Simulation ◽  
Moment Connections ◽  
Reduced Beam Section ◽  
Beam Section

scholarly journals Reduced Beam Section (RBS) Moment Connections-Analytical Investigation Using Finite Element Method

2018 ◽  
Vol 4 (6) ◽  
pp. 1240 ◽  
Author(s):  
Christos Sofias ◽  
Dimitra Tzourmakliotou
Keyword(s):  
Cross Sections ◽  
Computational Cost ◽  
Analytical Investigation ◽  
Moment Connections ◽  
Reduced Beam Section ◽  
Moment Resisting ◽  
Group A ◽  
Beam Section ◽  
Structural Parts ◽  
Group B

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.

Fragility Assessment of Reduced Beam Section Moment Connections

2010 ◽  
Vol 136 (9) ◽  
pp. 1140-1150 ◽  
Author(s):  
Dimitrios G. Lignos ◽  
Dimitrios Kolios ◽  
Eduardo Miranda
Keyword(s):  
Moment Connections ◽  
Reduced Beam Section ◽  
Beam Section

Cyclic performance of existing moment connections in steel retrofitted with a reduced beam section and bottom flange reinforcements

2007 ◽  
Vol 34 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Sang-Hoon Oh ◽  
Young-Ju Kim ◽  
Tae-Sup Moon
Keyword(s):  
Plastic Hinge ◽  
Composite Beams ◽  
Bottom Flange ◽  
Deformation Capacity ◽  
Moment Connections ◽  
Element Analysis ◽  
Reduced Beam Section ◽  
Steel Shape ◽  
The Face ◽  
Beam Section

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.

Fracture Moment Strength of Reduced Beam Section with Bolted Web Connections

2007 ◽  
Vol 348-349 ◽  
pp. 717-720
Author(s):  
Ki Hoon Moon ◽  
Sang Whan Han ◽  
Ji Eun Jung
Keyword(s):  
Moment Connections ◽  
Moment Capacity ◽  
Design Procedures ◽  
Reduced Beam Section ◽  
Moment Resisting ◽  
Current Design ◽  
Beam Section ◽  
The Moment ◽  
Rbs Connections ◽  
Experimental Researches

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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