Effect of Curvature Radius and Transverse Distribution of Load on Shear Lag for Curved Box Girders

2010 ◽  
Vol 163-167 ◽  
pp. 1555-1560
Author(s):  
Chang Feng Li ◽  
Wen Xue Du
Keyword(s):  
Coupling Effect ◽  
Curvature Radius ◽  
Curved Beam ◽  
Fundamental Theory ◽  
Shear Lag ◽  
Box Girders ◽  
Box Girder ◽  
Transverse Distribution ◽  
Thin Walled ◽  
The Galerkin Method

Based on fundamental theory and variational principle of thin-walled curved beam and taking into account of coupling effect of bend and shear lag, the paper mainly discusses the variation of curvature radius and the transverse distribution of load in order to analyze effect of shear lag in curved box girder. By means of variational method, the paper derivates the elastic differential equation and boundary conditions and gives numerical results of equations finally, results are obtained by the Galerkin method. It shows that the curvature radius and the transverse distribution of load in the shear lag of curved box girder is very important by comparing the calculating results.

Shear Lag in Thin-Walled Box Girder with Variable Section

2011 ◽  
Vol 194-196 ◽  
pp. 1165-1169
Author(s):  
Yu Hong Zhang ◽  
Zi Jiang Yang ◽  
Shi Zhong Liu
Keyword(s):  
Significant Influence ◽  
Width Ratio ◽  
Stiffness Ratio ◽  
Shear Lag ◽  
Box Girders ◽  
Box Girder ◽  
Lag Effects ◽  
Variable Section ◽  
Thin Walled ◽  
Span Width

In this paper, a equivalent-section method of analyzing shear lag effects in box girders is presented. The effect of two major parameters on shear lag is investigated for cantilever and continuous box girders with variable section under two kinds of loads. It is shown that the span-width ratio, in addition to the flange stiffness to total stiffness ratio, has a significant influence on the shear lag. Finally, conclusions are drawn with regard to further study and research.

Analysis of Effect Factors about Shear Lag in Curved Box Girder under Seismic Loads

2014 ◽  
Vol 926-930 ◽  
pp. 505-510
Author(s):  
Hai Lin Lu ◽  
Li Peng Chen ◽  
Song Bo Zhu ◽  
Chong Yong Wan ◽  
Jia Qi Qian
Keyword(s):  
Finite Element ◽  
Curvature Radius ◽  
Seismic Load ◽  
Finite Element Models ◽  
Seismic Loads ◽  
Shear Lag ◽  
Effect Factors ◽  
Box Girders ◽  
Box Girder ◽  
Lag Effect

The shear lag effect will cause damage to the curved box girders. And it will adversely affect the bridge’s seismic performance. In order to analyze the effect under seismic loads, finite element models were created in this paper. By changing the parameters, such as curvature radius, width and height, their influence on the shear lag were studied. Results show that the effect was more obvious in wide and flat box girders under seismic load.

scholarly journals Prediction of Shear Lag Effect in Thin-Walled Single-Box Multicell Box Girder Based on the Modified Warping Displacement Function

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xiayuan Li ◽  
Shui Wan ◽  
Kongjian Shen ◽  
Peng Zhou ◽  
Xiao Wang
Keyword(s):  
Internal Force ◽  
Displacement Function ◽  
Force Balance ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girders ◽  
Box Girder ◽  
Lag Effect ◽  
Warping Displacement ◽  
Thin Walled

In this study, an effective and accurate theoretical analysis method for predicting the shear lag effect in the thin-walled single-box multicell box girder is presented. The modifications of longitudinal warping displacement functions at the flanges are fully investigated, including the shear lag width (bij) of flanges, the coefficients (αij) of shear lag warping functions, the deformation compatibility conditions in flanges, and the internal force balance (D). The initial shear deformation (γ03) in the top lateral cantilever flanges is innovatively introduced in multicell box girders and obtained by the designed procedure. In addition, the transverse distribution function for describing the longitudinal warping displacement is deduced and expressed in the form of the cosine function. Based on the principle of minimum potential energy, the governing differential equations are derived and solved with the associated boundary and load conditions. The accuracy and applicability of the proposed method (SL-THY2) are validated for four thin-walled single-box multicell (two- and three-cell) box girders with the results derived from the solid finite element method.

Geometric Nonlinear Analysis of Curved Box Continuous Girders Considering Shear Lag Effect

2011 ◽  
Vol 243-249 ◽  
pp. 1811-1816 ◽  
Author(s):  
Qi Zhi Luo ◽  
Yu Ji Chen
Keyword(s):  
Large Deflection ◽  
Computational Method ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girders ◽  
Box Girder ◽  
Lag Effect ◽  
Thin Walled ◽  
Geometric Nonlinear Analysis ◽  
Good Agreement

The analytical theory and computational method for thin-walled curved box girders in terms of the shear lag effect and geometric nonlinearity are presented. Based on the potential variational principle and the theory of thin-walled box girders, the geometry nonlinear governing differential equations of thin-walled curved box girder considering the influence of the shear lag effect of flange’s stress and the large deflection is established. The equation is solved by means of Newton-Raphon iteration method. The results from the present method are in good agreement with those of the test and the segment method. The numerical examples are conducted to verify the accuracy and reliability of the present theories. It is shown that the proposed formulae and method could be referenced to the design for the thin-walled curved box girders considering shear lag effect.

Beam finite element for thin-walled box girders considering shear lag and shear deformation effects

2021 ◽  
Vol 233 ◽  
pp. 111867
Author(s):  
Xiayuan Li ◽  
Shui Wan ◽  
Yuanhai Zhang ◽  
Maoding Zhou ◽  
Yilung Mo
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Shear Lag ◽  
Box Girders ◽  
Thin Walled

Static response of curved steel thin-walled box-girder bridge subjected to Indian railway loading

2021 ◽  
Vol 108 (2) ◽  
pp. 63-74
Author(s):  
V. Verma ◽  
K. Nallasivam
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Box Girders ◽  
Box Girder ◽  
One Dimensional ◽  
Thin Walled ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Indian Railway ◽  
Different Response

Purpose: The primary objective of the current study is to numerically model the steel thin-walled curved box-girder bridge and to examine its various response parameters subjected to Indian Railway loading. Design/methodology/approach: The analysis is conducted by adopting a one dimensional curved thin-walled box-beam finite beam element based on finite element methodology. The scope of the work includes a computationally efficient, three-noded, one-dimensional representation of a thin-walled box-girder bridge, which is especially desirable for its preliminary analysis and design phase, as well as a study of the static characteristics of a steel curved bridge, which is critical for interpreting its dynamic response. Findings: The analytical results computed using finite element based MATLAB coding are presented in the form of various stress resultants under the effect of various combinations of Indian Railway loads. Additionally, the variation in different response parameters due to changes in radius and span length has also been investigated. Research limitations/implications: The research is restricted to the initial design and analysis phase of box-girder bridge, where the wall thickness is small as compared to the cross-section dimensions. The current approach can be extended to future research using a different method, such as Extended finite element technique on curved bridges by varying boundary conditions and number of elements. Originality/value: The validation of the adopted finite element approach is done by solving a numerical problem, which is in excellent agreement with the previous research findings. Also, previous studies had aimed at thin-walled box girders that had been exposed to point loading, uniformly distributed loading, or highway truck loading, but no research had been done on railway loading. Moreover, no previous research had performed the static analysis on thin-walled box-girders with six different response parameters, as the current study has. Engineers will benefit greatly from the research as it will help them predict the static behaviour of the curved thin-walled girder bridge, as well as assess their free vibration and dynamic response analysis.

scholarly journals Computation of Deflections for PC Box Girder Bridges with Corrugated Steel Webs considering the Effects of Shear Lag and Shear Deformation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Wei Ji ◽  
Kui Luo ◽  
Jingwei Zhang
Keyword(s):  
Shear Deformation ◽  
Prestressed Concrete ◽  
Displacement Function ◽  
Shear Lag ◽  
Longitudinal Displacement ◽  
Box Girders ◽  
Element Analysis ◽  
Box Girder ◽  
Bridge Model ◽  
Bridge Models

Prestressed concrete (PC) girders with corrugated steel webs (CSWs) have received considerable attention in the past two decades due to their light self-weight and high prestressing efficiency. Most previous studies were focused on the static behavior of CSWs and simple beams with CSWs. The calculation of deflection is an important part in the static analysis of structures. However, very few studies have been conducted to investigate the deflection of full PC girders or bridges with CSWs and no simple formulas are available for estimating their deflection under static loads. In addition, experimental work on full-scale bridges or scale bridge models with CSWs is very limited. In this paper, a formula for calculating the deflection of PC box girders with CSWs is derived. The longitudinal displacement function of PC box girders with CSWs, which can consider the shear lag effect and shear deformation of CSWs, is first derived. Based on the longitudinal displacement function, the formula for predicting the deflection of PC box girders with CSWs is derived using the variational principle method. The accuracy of the derived formula is verified against experimental results from a scaled bridge model and the finite element analysis results. Parametric studies are also performed, and the influences of shear lag and shear deformation on the deflection of the box girder with CSWs are investigated by considering different width-to-span ratios and different girder heights. The present study provides an effective and efficient tool for determining the deflection of PC box girders with CSWs.

scholarly journals Effect of Construction Method on Shear Lag in Prestressed Concrete Box Girders

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Shi-Jun Zhou
Keyword(s):  
Cross Sections ◽  
Prestressed Concrete ◽  
Construction Process ◽  
Shear Lag ◽  
Box Girders ◽  
Box Girder ◽  
Construction Methods ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge

Most of the previous researches conducted on shear lag of box girders were only concerned about simple types of structures, such as simply supported and cantilever beams. The structural systems concerned in these previous researches were considered as determined and unchangeable. In this paper, a finite element method considering shear lag and creep of concrete was presented to analyze the effect of dynamic construction process on shear lag in different types of concrete box-girder bridges. The shear lag effect of the three types of a two-span continuous concrete beam classified by construction methods was analyzed in detail according to construction process. Also, a three-span prestressed concrete box-girder bridge was analyzed according to the actual construction process. The shear lag coefficients and stresses on cross sections along the beam including shear lag were obtained. The different construction methods, the changes of structural system with the construction process, the changes of loading and boundary conditions with the construction process and time, the prestressing, and creep were all imitated in the calculations. From comparisons between the results for beams using different construction methods, useful conclusions were made.

scholarly journals Effects of Shear Lag in Steel Box Girders of a Crane Runway

2020 ◽  
Vol 22 (1) ◽  
pp. 23-31
Author(s):  
Cătălin Moga ◽  
Delia Drăgan ◽  
Raluca Nerișanu
Keyword(s):  
Maximum Stress ◽  
Approximate Theory ◽  
Shear Lag ◽  
Box Girders ◽  
Box Girder ◽  
The Real ◽  
Lag Effect ◽  
Bending Stresses ◽  
Bending Of Beams

Abstract The term of shear lag is related to the discrepancies between the approximate theory of the bending of beams and their real behaviour. It refers to the increases of the bending stresses near the flange-to-web junctions and the corresponding decreases in the flange stresses away from these junctions. In the case of wide flanges of plated structures, shear lag caused by shear strains, which are neglected in the conventional theory, may be taken into account by a reduced flange width concentrated along the webs of the steel girders. In EN 1993-1-5, the concept of taking shear lag into account is based on effective width of the flange which is defined in order to have the same total normal force in the gross flange subjected to the real transverse stress distribution as the effective flange subjected to a uniform stress equal to the maximum stress of the real transverse distribution. Some aspects concerning the shear lag phenomenon and a working example for a box girder of a heavy crane runway to illustrate the determination of the shear lag effect are also presented.

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