scholarly journals Distortional Buckling Analysis of Steel-Concrete Composite Girders in Negative Moment Area

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zhou Wangbao ◽  
Jiang Lizhong ◽  
Kang Juntao ◽  
Bao Minxi
Keyword(s):  
Coupling Effect ◽  
Bending Moment ◽  
Bottom Flange ◽  
Distortional Buckling ◽  
Box Girders ◽  
Composite Girder ◽  
Axial Forces ◽  
Negative Moment ◽  
Applied Forces ◽  
Composite Girders

Distortional buckling is one of the most important buckling modes of the steel-concrete composite girder under negative moment. In this study, the equivalent lateral and torsional restraints of the bottom flange of a steel-concrete composite girder under negative moments due to variable axial forces are thoroughly investigated. The results show that there is a coupling effect between the applied forces and the lateral and torsional restraint of the bottom flange. Based on the calculation formula of lateral and torsional restraints, the critical buckling stress of I-steel-concrete composite girders and steel-concrete composite box girders under variable axial force is obtained. The critical bending moment of the steel-concrete composite girders can be further calculated. Compared to the traditional calculation methods of elastic foundation beam, the paper introduces an improved method, which considers coupling effect of the external loads and the foundation spring constraints of the bottom flange. Fifteen examples of the steel-concrete composite girders in different conditions are calculated. The calculation results show a good match between the hand calculation and the ANSYS finite element method, which validated that the analytic calculation method proposed in this paper is practical.

Elastic Distortional Buckling Analysis of I-Steel Concrete Composite Beam Considering Shear Deformation

2016 ◽  
Vol 16 (08) ◽  
pp. 1550045 ◽  
Author(s):  
Wang-Bao Zhou ◽  
Li-Zhong Jiang ◽  
Shu-Jin Li ◽  
Fan Kong
Keyword(s):  
Shear Deformation ◽  
Composite Beam ◽  
Coupling Effect ◽  
Bottom Flange ◽  
Distortional Buckling ◽  
Related Factors ◽  
Factors Affecting ◽  
Buckling Stress ◽  
Negative Moment ◽  
Applied Forces

Elastic distortional buckling is one of the essential buckling modes of the I-steel concrete composite beam (ISCCB); such buckling often occurs under the gradient of negative moment. The key factors affecting the kind of buckling are the “torsional” and “lateral” restraint stiffnesses of the bottom flange of the beam. This paper investigates the equivalent lateral and torsional restraint stiffnesses of the bottom flange of the ISCCB under the gradient of negative moment. The relations for estimating the lateral and torsional restraint stiffnesses are used to determine the critical distortional buckling stress and associated buckling moment of the beam under the gradient of negative moment. A new method is proposed for assessing the buckling of the elastic-foundation beam, by which the related factors are considered: (1) The coupling effect between the applied forces and lateral/torsional restraint stiffness of the bottom flange of the beam, (2) the effect of gradient of a moment and (3) the effect of shear deformation of the web. The proposed method has been compared with those available by using the data of 15 cases under different loading conditions; the results show that the present method is much more accurate and reliable than the existing ones. The method as proposed herein is recommended for further research in relation to the buckling of the ISCCB.

scholarly journals Driven Pile Effects on Nearby Cylindrical and Semi-Tapered Pile in Sandy Clay

2021 ◽  
Vol 11 (7) ◽  
pp. 2919
Author(s):  
Massamba Fall ◽  
Zhengguo Gao ◽  
Becaye Cissokho Ndiaye
Keyword(s):  
Coupling Effect ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Adaptive Mesh ◽  
Pile Driving ◽  
Arbitrary Lagrangian Eulerian ◽  
Axial Forces ◽  
Tapered Pile ◽  
Driven Pile ◽  
The Impact

A pile foundation is commonly adopted for transferring superstructure loads into the ground in weaker soil. They diminish the settlement of the infrastructure and augment the soil-bearing capacity. This paper emphases the pile-driving effect on an existing adjacent cylindrical and semi-tapered pile. Driving a three-dimensional pile into the ground is fruitfully accomplished by combining the arbitrary Lagrangian–Eulerian (ALE) adaptive mesh and element deletion methods without adopting any assumptions that would simplify the simulation. Axial forces, bending moment, and lateral displacement were studied in the neighboring already-installed pile. An investigation was made into some factors affecting the forces and bending moment, such as pile spacing and the shape of the already-installed pile (cylindrical, tapered, or semi-tapered). An important response was observed in the impact of the driven pile on the nearby existing one, the bending moment and axial forces were not negligible, and when the pile was loaded, it was recommended to consider the coupling effect. Moreover, the adjacent semi-tapered pile was subjected to less axial and lateral movement than the cylindrical one with the same length and volume for taper angles smaller than 1.0°, and vice versa for taper angles greater than 1.4°.

scholarly journals Lateral distortional buckling of cellular composite-beams

2018 ◽  
Vol 11 (2) ◽  
pp. 331-356 ◽  
Author(s):  
A. D. PIASSI ◽  
J. V. DIAS ◽  
A. F. G. CALENZANI ◽  
F. C. C. MENANDRO
Keyword(s):  
Flexural Rigidity ◽  
Lateral Displacement ◽  
Limit State ◽  
Composite Beams ◽  
Bottom Flange ◽  
Distortional Buckling ◽  
Critical Moment ◽  
Negative Moment ◽  
Resistant Moment ◽  
Negative Bending

Abstract In the region of negative bending moments of continuous and semi-continuous steel and concrete composite beams, the inferior portion of the steel section is subjected to compression while the top flange is restricted by the slab, which may cause a global instability limit state know as lateral distortional buckling (LDB) characterized by a lateral displacement and rotation of the bottom flange with a distortion of the section’s web when it doesn’t have enough flexural rigidity. The ABNT NBR 8800:2008 provides an approximate procedure for the verification of this limit state, in which the resistant moment to LDB is obtained from the elastic critical moment in the negative moment region. One of the essential parameters for the evaluation of the critical moment is the composite beam’s rotational rigidity. This procedure is restricted only to to steel and concrete composite beams with sections that have plane webs. In this paper, an equation for the calculation of the rotational rigidity of cellular sections was developed in order to determine the LDB elastic critical moment. The formulation was verified by numerical analyses performed in ANSYS and its efficiency was confirmed. Finally, the procedure described in ABNT NBR 8800:2008 for the calculation of the critical LDB moment was expanded to composite beams with cellular sections in a numerical example with the appropriate modifications in geometric properties and rotational rigidity.

Experimental study on partial-combination method in continuous composite girder

2021 ◽  
Author(s):  
Hang Su ◽  
Qingtian Su ◽  
Wensheng Yu ◽  
Yunjin Wang ◽  
Minghui Zeng
Keyword(s):  
Concrete Slab ◽  
Bending Moment ◽  
Combination Method ◽  
Steel Girder ◽  
Advantages And Disadvantages ◽  
Girder Bridges ◽  
Composite Girder ◽  
Rubber Sleeve ◽  
Negative Bending ◽  
Composite Girders

<p>Cracking of concrete slab in the negative bending moment region of continuous composite girders is a key problem which needs to be solved in the design of continuous composite girder bridges. The main reason of concrete cracking in the negative bending moment region of continuous composite girder is tensile stress under the effects of temperature and load in the portion of integration. The paper gives the method of partial-combination to connect steel girder with concrete slab, that is, a rubber sleeve is placed on the stud of the negative bending moment region to increase the slip between the concrete slab and the steel girder at the joint. Two specimens of negative bending moment region are designed to observe the mechanical properties in the negative bending moment region of composite girders when using the method of partial-combination. The advantages and disadvantages of the partial-combination method are analysed.</p>

scholarly journals Finite Element Analysis of Overlapped Z-Purlins Restrained by Sheeting

2021 ◽  
Vol 1203 (3) ◽  
pp. 032077
Author(s):  
Ioan Andrei Gîrbacea ◽  
Viorel Ungureanu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Mode ◽  
Bending Moment ◽  
Major Influence ◽  
Bottom Flange ◽  
Distortional Buckling ◽  
Element Analysis ◽  
Moment Distribution ◽  
The Moment

Abstract Cold-formed steel Z-purlins with overlapping at the intermediate supports ensures the continuity of the bending moment. A continuous beam with two equal spans of 6 m is investigated under gravity loading using the finite element method. The numerical model includes the beneficial interaction between the Z-purlins and the trapezoidal sheeting. Finite element results show that the screw spacing and sheeting thickness has a limited influence on the resistance of the member. The effect of the overlapping length and detailing of the connection is studied through a parametric study. Six overlaps varying from 100mm to 1200mm (1.6% to 20% of one span) capture the change of the failure mode from the overlap edge to the support region of the purlin. The connection detailing is studied considering multiple bolt/screw patterns. The detailing and length of the overlap connection has a major influence on the moment distribution and consequently on the failure mode. The detailed finite element analysis shows that assuming the beam connection as continuous in 1D beam models lead to an unrealistic bending moment distribution and failure mode. Connecting the bottom flange using screws improves the overall load carrying capacity of the beam especially for short overlap lengths. The increase in resistance is attributed to the restraining effect on the free flange which fails due to distortional buckling.

Model Test of Steel-Concrete Composite Beam Deck under Negative Moment

2021 ◽  
Vol 871 ◽  
pp. 340-348
Author(s):  
Rui Rong ◽  
Yu Hui Shan ◽  
Li Zhao ◽  
Bao Qun Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Model Test ◽  
Composite Beam ◽  
Bending Moment ◽  
Cable Stayed Bridge ◽  
Composite Girder ◽  
Force Transfer ◽  
Negative Moment ◽  
Negative Bending

In order to understand the mechanical properties and force transfer law of steel-concrete composite beam deck under negative bending moment, and further guide the design. Based on a steel-concrete composite girder cable-stayed bridge, the model test of the mechanical behavior of the steel-concrete composite girder deck under the action of negative moment was carried out. The characteristics of mechanical failure and mechanical properties were analyzed.

scholarly journals Influence of end Contsrains on the Global Behaviour of a Box Girder

2016 ◽  
Vol 6 (1) ◽  
pp. 7-15
Author(s):  
Daniela Mihaela Boca ◽  
A. Faur ◽  
A. Boca
Keyword(s):  
Prestressed Concrete ◽  
Transport Infrastructure ◽  
Box Girders ◽  
3D Fem ◽  
Important Data ◽  
Box Girder ◽  
Fem Model ◽  
Global Behaviour ◽  
Applied Forces ◽  
Precast Prestressed Concrete

Abstract This study aims to presents the importance of end constrains, boundary conditions and position of the applied forces regarding the design of precast/prestressed concrete box girders. The study is based on a destructive test which was performed on a 37.1 m span single-cell prestressed concrete box girder. The scope of the test was to certify the usage of such girders for the new Transylvania motorway bridges. The test is numerically reproduced through a full 3D FEM model implemented in SAP2000. The influence of the end diaphragms is considered by analysing the beam’s behaviour to six loading conditions: one of which is replicating the loadings during the test, while the others are conceived as real vertical and horizontally loading scenarios. The results obtained for the girders with and without end constrains are compared. The performances of both design solutions in the presence of prestressing are highlighted where applicable. It is considered that the results of this study may provide very important data if considering that Romania has an urgent need to realize a modern and an adequate transport infrastructure.

The Fatigue Behavior of Negative Moment Regions of Continuous Composite Beams at Low Temperatures

1975 ◽  
Vol 2 (1) ◽  
pp. 98-115
Author(s):  
A. E. Long ◽  
K. Van Dalen ◽  
P. Csagoly
Keyword(s):  
Fatigue Behavior ◽  
Bending Moment ◽  
Composite Beams ◽  
Horizontal Shear ◽  
Shear Connectors ◽  
Significant Difference ◽  
Show Evidence ◽  
Negative Moment ◽  
Central Support ◽  
Push Out

The fatigue behavior of the negative moment region of continuous steel–concrete composite beams under Canadian temperature conditions was studied. Tests were conducted on three 26 ft 0 in. (7.92 m) long beams, continuous over a central support, and on 11 conventional push-out specimens. These were supplemented by a theoretical study of the internal forces in the beams using an iterative method of analysis.The close agreement between measured and theoretical strains and deflections indicated that good interaction was achieved throughout the length of the beams. The beams sustained 500 000 cycles of loading with no serious deterioration of composite action. The pattern of stud failures was consistent from beam to beam and reflected closely the calculated distribution of horizontal shear force at the steel–concrete interface. Stud shear connectors in the negative moment region where the slab had cracked in tension were found to be slightly less effective than studs in the positive bending moment regions.Neither the detailed study of individual connectors in the beams nor the results of the push-out tests show evidence of a reduction in the fatigue life of studs at −20 °F (−29 °C) relative to room temperature. The beams also exhibited no significant difference in their overall performance at these two temperatures.

Estimation of Ultimate Longitudinal Bending Moment of Ships and Box Girders

1996 ◽  
Vol 40 (03) ◽  
pp. 244-257 ◽  
Author(s):  
M. K. Rahman ◽  
M. Chowdhury
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Fortran Program ◽  
Box Girders ◽  
Limit States ◽  
Box Girder ◽  
Stiffened Panels ◽  
Complete Procedure ◽  
Longitudinal Bending ◽  
Collapse Behavior

The paper describes a methodology of computing the ultimate value of the longitudinal bending moment at any cross section of a ship or box girder. The cross section has been discretized into stiffened panels (one stiffener with its associated effective plating). The limit states for these panels, both tensile and compressive, are modeled in an appropriate manner. Since the ultimate strength of the girder section is largely governed by the behavior of the panels under compression, the authors have paid special attention in modeling the collapse as well as post-collapse behavior of these panels. A new stress-strain relationship is also introduced. The complete procedure has been coded into a FORTRAN program and tested against a number of box girder models and an actual ship for which the true behavior was known. The results obtained from the proposed program appear to be quite satisfactory. Good correlation was also found when compared with the results obtained by more complex and rigorous analytical methods.

Shear tab connection with composite beam subjected to transient-state fire temperatures

2019 ◽  
Vol 10 (4) ◽  
pp. 411-434 ◽  
Author(s):  
Mohammad Hajjar ◽  
Elie Hantouche ◽  
Ahmad El Ghor
Keyword(s):  
Composite Beam ◽  
Transient State ◽  
Composite Beams ◽  
Slab Thickness ◽  
Bottom Flange ◽  
Rational Model ◽  
Content Type ◽  
Geometrical Properties ◽  
Axial Forces ◽  
Shear Tab

Purpose This study aims to develop a rational model to predict the thermal axial forces developed in shear tab connections with composite beams when subjected to transient-state fire temperatures. Design/methodology/approach Finite element (FE) models are first developed in ABAQUS and validated against experimental data available in the literature. Second, a parametric study is conducted to identify the major parameters that affect the behavior of shear tab connections with composite beams in the fire. This includes beam length, shear tab thickness, shear tab location, concrete slab thickness, setback distance and partial composite action. A design-oriented model is developed to predict the thermal induced axial forces during the heating and cooling phases of a fire event. The model consists of multi-linear springs that can predict the stiffness and strength of each component of the connection with the composite beam. Findings The FE results show that significant thermal axial forces are generated in the composite beam in the fire. This is prominent when the beam bottom flange comes in contact with the column. Fracture at the toe of the welds governs the behavior during the cooling phase in most FE simulations. Also, the rational model is validated against the FE results and is capable of predicting the thermal axial forces developed in shear tab connections with composite beams under different geometrical properties. Originality/value The proposed model can predict the thermal axial force demand and can be used in performance-based approaches in future structural fire engineering applications.

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