Mechanical Behavior of Concrete Filled Steel Tubular out Stiffener Ring Connections with Reduced Beam Section

2011 ◽  
Vol 243-249 ◽  
pp. 865-870
Author(s):  
Cheng Yu Li ◽  
Yao Jie Guo
Keyword(s):  
Stress Concentration ◽  
Plastic Hinge ◽  
Plastic Region ◽  
Joint Stiffness ◽  
Repeated Loading ◽  
Past Study ◽  
Joint Region ◽  
Reduced Beam Section ◽  
Beam Section ◽  
Strong Joint

The past study indicates that, when the space joint of concentric annular-stiffer is loaded, stress concentration may generate at corner. The destruction usually concentrates in the joint region, and then cannot generate “strong joint”. To change this unfavorable characteristic, the reduced beam section connection is adopted. Through oriented reducing beam section, the plastic region is formed, which can achieve the aim of “weak beam, strong joint”. After the simulation and analysis to space joints on outer concentric annular-stiffer which are processed by reduced beam section, the loading conditions of the joints are obviously improved in the following aspects: (1) the stress distribution on annular plate is smoothed obviously, the degree of stress concentration on corner is significantly decreased; (2) to assure plastic hinge firstly appear on the beam end but not the ring surface, we can change the size of ring plate, length of beam and the flange weaken degree; (3)the joint stiffness does not decrease during the stage of elastic loading; (4)under repeated loading, the joint region has little change and the plastic expansion on the ring surface is not obvious. Above all, reducing beam section can improve the mechanical properties of CFST-steel beam space joints with outer concentric annular-stiffer, thus the “strong joint” requirement could be fulfilled.

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.

Comparative Study of Steel Beam Column Connection under Cyclic Loading

2016 ◽  
Vol 857 ◽  
pp. 53-58
Author(s):  
S. Anisha ◽  
Dhanya Krishnan
Keyword(s):  
Cross Section ◽  
Plastic Hinge ◽  
Steel Beam ◽  
Cross Sectional ◽  
Reduced Beam Section ◽  
Cross Section Area ◽  
Section Area ◽  
Beam Section ◽  
The Cross ◽  
Stress And Deformation

A structure is an assembly of various elements or components which are fastened together through some type of connections. Steel beam column connection may fail due to large earth quake. Plastic hinge formation is the main failure of a steel beam column connection. There are two methods for improving the steel beam column connection (i) connection reinforcement/strengthening (ii) beam weakening by reducing the cross-sectional area of the beam at a certain distance from the connection. When reducing the cross section area plastic hinge is formed away from column face. The main objective of this study is to compare reduced beam section (RBS) and reduced web section (RWS) pattern and find out the location of plastic hinge. For steel beam column plastic hinge is located near column. When reducing the cross section area the location of plastic hinge will shift from the column. Aim of this project is to locate the position of plastic hinge apart from column face, and also evaluate the stress and deformation.

Seismic Performance of Concrete-Filled Square Tubular Column and Reduced Steel Beam Joints

2010 ◽  
Vol 163-167 ◽  
pp. 4257-4264
Author(s):  
Yan Li Guo ◽  
Xing You Yao
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Plastic Hinge ◽  
Steel Beam ◽  
Load Carrying Capacity ◽  
Reduced Beam Section ◽  
Load Carrying ◽  
Beam Section ◽  
Ultimate Load Carrying Capacity ◽  
Material Nonlinear

According to anti-seismic design principle of strong column and weak beam, and of strong joint and weak member, reduced beam section (RSB) is often used to shift away plastic hinge from end of beam to the weaken region of the beam. The non-linear finite element models are established for concrete-filled steel square tubular column and reduced steel beam with holes in flange or in flange and web, considering geometric large deformation and material nonlinear. Comparison is made on load-displacement curves, the stress distribution of reduced beams, the ultimate load-carrying capacity, the ductility, and the energy-dissipating ability between analysis results of different RBS joints and experimental results. It shows that the stiffness and ultimate load-carrying capacity of new RBS joints are close to traditional RBS joint, the plastic hinge in the new joints with reduced beam section can be moved to the reduced region, and the new joints display good ductility, energy-dissipating ability and seismic behavior.

Study on Mechanical Behavior of Concrete-Filled Square Tubular Column and Bolt-Weld Steel Beam Joints with Reduced Beam Section

2010 ◽  
Vol 163-167 ◽  
pp. 620-623
Author(s):  
Shao Feng Nie ◽  
Tian Hua Zhou ◽  
Xiang Bin Liu ◽  
Xiu Mei Wang
Keyword(s):  
Plastic Hinge ◽  
3D Models ◽  
Steel Beams ◽  
Steel Beam ◽  
Initial Stiffness ◽  
Nonlinear Fem ◽  
Reduced Beam Section ◽  
Weld Joints ◽  
Beam Section ◽  
3D Solid

The nonlinear FEM models of concrete-filled square tubular column with internal diaphragms and steel beams with reduced beam section bolt-weld joints, involving geometric, materials and contact nonlinear, were established. The 3D models of beam-to-column joints with internal diaphragms by 3D solid elements are founded. The bearing capacity behavior of joints under the monotonic loading are analyzed, including P-Δ curves, the stresses distribution of beam, the dissipating energy ability and destruction form. The analysis results show that the initial stiffness of joint with reduced beam section is close to that of non-reduced beam section joint. The bearing capacities of joints with reduced beam section are lower a little than that of non-reduced beam section joint. The plastic hinge in the joint with reduced beam section is removed to the reduced beam region.

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 INVESTIGATION OF BEHAVIOR OF INTERIOR STEEL CONNECTIONS WITH OPENINGS IN BEAM WEB AND FLANGE UNDER MONOTONIC LOADING

2021 ◽  
Keyword(s):  
Plastic Hinge ◽  
Local Buckling ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Reduced Beam Section ◽  
Steel Connections ◽  
Finite Element Software ◽  
Expected Performance ◽  
Rigid Connection ◽  
Beam Section

Connections are considered to be one of the most prominent components of steel moment frames and have received studious attention in recent years. The core problem of welded connections is premature brittle fracture of weld in the critical beam-to-column connection region. Within the framework of this issue, various approaches have been proposed to solve the mentioned problem. Intentional weakening of the beam web or flange is in line with the purpose of leading the plastic hinge away from the column face, hence, increasing the ductility. The aim of this research is to investigate the behavior of interior connections subjected to monotonic lateral loading in case of presence of openings in beam web or flange. To do so, an ordinary fully welded rigid connection, reduced beam section, reduced web section, and drilled flange connection models are simulated numerically, utilizing finite element software, ANSYS. The results indicate that scrupulous selection of opening sizes are of great importance to fulfill the desired outcome which is avoiding the brittle failure of connections. Furthermore, the use of drilled flange, reduced beam section, or reduced web section connections satisfy the expected performance and it is proposed to use them according to practicability, architectural and economic considerations as well as site conditions. Shear deformation and local buckling is observed in reduced web section connections while in drilled flange connections, stress concentration around the opening is critical.

The Mechanical Behavior Study on Reduced Beam Section and Widened Beam Section Connections of Steel Frames

2010 ◽  
Vol 163-167 ◽  
pp. 717-725
Author(s):  
Yan Wang ◽  
Xiu Li Liu ◽  
You Sheng Yu
Keyword(s):  
Mechanical Behavior ◽  
Bearing Capacity ◽  
Design Parameter ◽  
Plastic Hinge ◽  
Steel Frames ◽  
Local Area ◽  
Reduced Beam Section ◽  
Behavior Study ◽  
Beam Section ◽  
Elastic Stage

In the paper, finite element models are established by using numerical methods to study the mechanical behavior of these kinds of connections. By discussing the range of design parameter of reduced beam section connection and widened beam section connection, stress distribution of connections and the influence of design parameter on bearing capacity at elastic stage and plastic stage are studied. The FEM models of these two kinds of connections behaved good ductility behavior. The purpose of moving plastic hinge outward from the beam and column interface is realized. Stress concentration near welds at the end of beam is reduced significantly. The bearing capacity of widened beam section connection increase obviously due to expanding the local area of beam flanges at the end of beam, but that of reduced beam section connection decrease due to trimming beam flanges. After studies, the range of design parameter of reduced beam section connection and widened beam section connection are given in the paper, and comparing with FEMA-350 [14] of American. The suggestion parameters would be useful for seismic design of steel frames.

Shape Optimization and Seismic Design of Concrete-Filled Square Tubular Column and Reduced Beam Section with Cut Web

2010 ◽  
Vol 163-167 ◽  
pp. 2397-2403
Author(s):  
Yan Li Guo ◽  
Xing You Yao
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Plastic Hinge ◽  
Von Mises Stress ◽  
Reduced Beam Section ◽  
Weak Beam ◽  
Beam Section ◽  
Ultimate Load Carrying Capacity ◽  
Seismic Design Method ◽  
Von Mises

According to anti-seismic design principle of strong column and weak beam, and of strong joint and weak member, reduced beam section(RBS) is often used to shift away plastic hinge from end of beam to weaken region of the beam. Reduced beam section with cut web are analyzed by non-linear finite element method(FEM) in this paper. Two kinds of effective suggested joints of reduced beam section(circled hole and long-circled hole) are put forward by comparing the results of mechanical behavior of reduced beam section with which of traditional RBS, including of ultimate load-carrying capacity, Von-mises stress distribution and the place of largest stress of beam end of the beam-column joints. A proposed seismic design method is put forward according to related chinese codes.

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.

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