scholarly journals RBS moment connection analysis using a solid model

2021 ◽  
Author(s):  
Mikaela Coello-Mena
Keyword(s):  
Seismic Event ◽  
Plastic Hinge ◽  
Efficient Design ◽  
Moment Connections ◽  
Reduced Beam Section ◽  
Moment Connection ◽  
Steel Moment Connection ◽  
Cutting Out ◽  
Beam Section ◽  
Rbs Connections

The unpredictability of the steel beam welding connection has led to many solutions, including the are of focus for this research Reduced Beam Section ( Moment Connections The RBS in steel moment connection facilitates the calculation and predictability of failure in design The RBS section is created by cutting out part of the flanges in a beam This creates a plastic hinge where the beam will fail first 1 This creates a model of predictability on the durability and strength of the beams Creating a RBS connection increases the overall ductility of the steel frame The RBS section reduces the flange width which causes stress concentration on the reduced section and this then lowers the stress on the welds. The lower stress then prevents unexpected brittle fracture in the welding a predicted plastic deformation of the RBS section during a seismic event 2 3 The research is focused on optimizing the RBS connection Finite models will be created using ANSYS to investigate how different RBS connections react in different situations and what is the most efficient design in terms of safety and cost.

scholarly journals RBS moment connection analysis using a solid model

2021 ◽  
Author(s):  
Mikaela Coello-Mena
Keyword(s):  
Seismic Event ◽  
Plastic Hinge ◽  
Efficient Design ◽  
Moment Connections ◽  
Reduced Beam Section ◽  
Moment Connection ◽  
Steel Moment Connection ◽  
Cutting Out ◽  
Beam Section ◽  
Rbs Connections

The unpredictability of the steel beam welding connection has led to many solutions, including the are of focus for this research Reduced Beam Section ( Moment Connections The RBS in steel moment connection facilitates the calculation and predictability of failure in design The RBS section is created by cutting out part of the flanges in a beam This creates a plastic hinge where the beam will fail first 1 This creates a model of predictability on the durability and strength of the beams Creating a RBS connection increases the overall ductility of the steel frame The RBS section reduces the flange width which causes stress concentration on the reduced section and this then lowers the stress on the welds. The lower stress then prevents unexpected brittle fracture in the welding a predicted plastic deformation of the RBS section during a seismic event 2 3 The research is focused on optimizing the RBS connection Finite models will be created using ANSYS to investigate how different RBS connections react in different situations and what is the most efficient design in terms of safety and cost.

Experimental Investigation of Reduced Beam Section Moment Connections without Continuity Plates

2004 ◽  
Vol 20 (4) ◽  
pp. 1185-1209 ◽  
Author(s):  
Chris P. Pantelides ◽  
Yasuteru Okahashi ◽  
Lawrence D. Reaveley
Keyword(s):  
Steel Buildings ◽  
Moment Frames ◽  
Moment Connections ◽  
Steel Moment Frame ◽  
Reduced Beam Section ◽  
Panel Zone ◽  
Moment Connection ◽  
Beam Section ◽  
Rbs Connections ◽  
Continuity Plates

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.

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.

Numerical Evaluation of New Reduced Beam Section Moment Connection

2008 ◽  
Author(s):  
Ali Imanpour ◽  
Rasoul Mirghaderi ◽  
Farhad Keshavarzi ◽  
Bardia Khafaf
Keyword(s):  
Numerical Evaluation ◽  
Reduced Beam Section ◽  
Moment Connection ◽  
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.

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