EVALUATION OF PERFORMANCE OF BEAM COLUMN JOINT WITH REDUCED BEAM SECTION

2020 ◽  
Vol 9 (7) ◽  
pp. 1-10
Keyword(s):  
Cross Section ◽  
Progressive Collapse ◽  
Plastic Hinge ◽  
Beam Theory ◽  
Steel Structures ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Reduced Beam Section ◽  
Weak Beam ◽  
Beam Section

This study reviews mainly holistic design of PEB structure and comparison of behavior of reduced beam section at beam column sub assemblage. Commercial software based on finite element analysis is used for carrying out mathematical modeling and analysis. In recent construction work it is observed that during conditions like earthquake or cyclone connections fails resulting in to progressive collapse. Also it damages column resulting in failure of strong column weak beam theory. In present work after identifying problem structure is fused at connection by reducing beam cross section at location of connection. This is done by reducing cross section of beam in plan expected to result in shifting of plastic hinge from face of column. Reduced beam sections capacity is calculated by simple calculations and verifying them with moment curvature relationships at desired locations. This will concentrate on failure of fuse and not of connection during load application. Motivation of this study is to improve connection by fulfilling strong column and weak beam theory. This will motivate construction industry to utilize steel structures more often assuring repairing of structure as element failure will be dominant over failure of entire structure

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.

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.

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.

scholarly journals Seismic Analysis of Multi Storey Building Using Strong Column Weak Beam Ratio (SCWB) in Different Zones of India

2021 ◽  
Vol 9 (VII) ◽  
pp. 1411-1421
Author(s):  
Suraj Raut
Keyword(s):  
Failure Modes ◽  
Seismic Analysis ◽  
Progressive Collapse ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Moment Of Inertia ◽  
Seismic Action ◽  
Weak Beam ◽  
Ultimate Moment ◽  
Moment Of Resistance

An earthquake structures are mandatory to avoid significant damages (i.e., collapse) and aims that structure withstand a major earthquake without collapse. The design approach adopted is to ensure that the columns of the structure more capable to resist moments than beam; to avoid progressive collapse of structure due to failure of columns in lower level; it is necessary the columns have stronger than beams (strong column weak beam). The concept of SCWB is to ensure that plastic hinge formed in the beam not in the column; this help in dissipating the more energy along with providing ductility to the structure. If the plastic hinge is formed on the both ends of column then, the column is not able to spread the plasticity and collapse which are leads to global failure. The failure modes in all past earthquake is exactly opposite i.e, strong beam weak column; and comes to sway mechanism and fails to collapse. For this it is foreseen that the values of ratio of Mc/Mb (ratio of sum of ultimate moment of resistance of columns to sum of ultimate moment of resistance of beam) in the beam-column joint are stated by many design codes and the values are different ranging from 1.2,1.3,1.4,1.5 to 2, etc. Another effect of ratio Ic/Ib (ratio of moment of inertia of column to moment of inertia of beam) have been studied but the exact meeting of SCWB behaviour in the structures at the time of collapse not stated clearly. The Mc/Mb and Ic/Ib ratio are very important to prevent damage in the structure under seismic action. In the present work, attempts are made to achieve exact ratio of exact strong column weak beam. In this study, the combined effect of two ratio (Mc/Mb, Ic/Ib) simultaneously investigated in different zones of India to find out exact SCWB ratio’s value for to meet the SCWB behaviour. Different numerical examples are presented of combine ratios (Mc/Mb,Ic/Ib) and pushover analysis is performed on each ratio’s. The result of the investigation highlighted on the objective that is to find exact SCWB ratio value considering the parameter like target displacement, ductility ratio, hinge response etc.

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.

Coupled Deformation Modes in the Large Deformation Finite-Element Analysis: Problem Definition

2006 ◽  
Vol 2 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Bassam A. Hussein ◽  
Hiroyuki Sugiyama ◽  
Ahmed A. Shabana
Keyword(s):  
Large Deformation ◽  
Cross Section ◽  
Flexible Structures ◽  
Beam Theory ◽  
Problem Definition ◽  
Beam Model ◽  
Element Analysis ◽  
Elastic Line ◽  
The Cross ◽  
Deformation Modes

In the classical formulations of beam problems, the beam cross section is assumed to remain rigid when the beam deforms. In Euler–Bernoulli beam theory, the rigid cross section remains perpendicular to the beam centerline; while in the more general Timoshenko beam theory the rigid cross section is permitted to rotate due to the shear deformation, and as a result, the cross section can have an arbitrary rotation with respect to the beam centerline. In more general beam models as the ones based on the absolute nodal coordinate formulation (ANCF), the cross section is allowed to deform and it is no longer treated as a rigid surface. These more general models lead to new geometric terms that do not appear in the classical formulations of beams. Some of these geometric terms are the result of the coupling between the deformation of the cross section and other modes of deformations such as bending and they lead to a new set of modes referred to in this paper as the ANCF-coupled deformation modes. The effect of the ANCF-coupled deformation modes can be significant in the case of very flexible structures. In this investigation, three different large deformation dynamic beam models are discussed and compared in order to investigate the effect of the ANCF-coupled deformation modes. The three methods differ in the way the beam elastic forces are calculated. The first method is based on a general continuum mechanics approach that leads to a model that includes the ANCF-coupled deformation modes; while the second method is based on the elastic line approach that systematically eliminates these modes. The ANCF-coupled deformation modes eliminated in the elastic line approach are identified and the effect of such deformation modes on the efficiency and accuracy of the numerical solution is discussed. The third large deformation beam model discussed in this investigation is based on the Hellinger–Reissner principle that can be used to eliminate the shear locking encountered in some beam models. Numerical examples are presented in order to demonstrate the use and compare the results of the three different beam formulations. It is shown that while the effect of the ANCF-coupled deformation modes is not significant in very stiff and moderately stiff structures, the effect of these modes can not be neglected in the case of very flexible structures.

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.

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