Shear Lag Effect in Single Plane Cable-Stayed Bridge

1998 ◽  
Vol 1 (4) ◽  
pp. 301-306 ◽  
Author(s):  
Shih Toh Chang ◽  
Qiwei Zhang ◽  
Shiduo Zhang
Keyword(s):  
Axial Force ◽  
Beam Theory ◽  
Test Results ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Single Plane ◽  
Cable Stayed Bridge ◽  
Lag Effect ◽  
Combined Action ◽  
Minimum Potential

The shear lag effect in thin-walled trapezoidal box sections with inclined stiffeners within the cell is analyzed using the principle of minimum potential energy. Due to the combined action of axial force and moment in a cable-stayed bridge, the normal stress in the pylon is given by [Formula: see text]. The coefficient of shear lag can be written as [Formula: see text], where σ is the actual stress taking shear deformation of slabs into account and [Formula: see text] is the stress evaluated by elementary beam theory. In this paper, the longitudinal displacement under axial force is assumed to vary parabolically transversely across the section. Due to moment, a quartic variation is adopted. Two sets of differential equations with boundary conditions are theoretically derived. An example is illustrated by theoretical analysis and test results.

Influence of Main Structural Dimension on the Shear Lag Effect of Box Girder Used in Cable-Stayed Bridge

2013 ◽  
Vol 405-408 ◽  
pp. 1483-1488 ◽  
Author(s):  
Yu Ping Zhang ◽  
Chuan Xi Li
Keyword(s):  
Shell Element ◽  
Parameter Analysis ◽  
Bottom Flange ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Thickness Change ◽  
Cable Stayed Bridge ◽  
Flange Thickness ◽  
Lag Effect

Through simulating box girder with shell element, the influence of the top flangebottom flange and web thickness on the shear lag effect of box girder used in cable-stayed bridge was discussed on the background of Jianning bridge in Zhuzhou. Parameter analysis of the thickness change of the top flange, bottom flange and web on shear lag effect of box girder was based on analyzing and comparing the calculated results. The results show that the thickness change of the top flange, bottom flange and web have more influence on the shear lag effect of top flange than that of bottom flange; thickness increase of bottom flange and web can make the shear lag effect intensified obviously; and thickness change of web has the most significant influence on the shear lag effect among them for box girder with single box and three rooms used in cable-stayed bridges.

scholarly journals Shear Lag Effect In The Numerical Experiment

2015 ◽  
Vol 61 (3) ◽  
pp. 31-50 ◽  
Author(s):  
M. Szumigała ◽  
K. Ciesielczyk
Keyword(s):  
3D Model ◽  
Beam Theory ◽  
Structural Elements ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Lag Effects ◽  
Plate Buckling ◽  
Lag Effect ◽  
Comparison Of The Results ◽  
Elastic Shear

AbstractThe standard PN-EN 1993-1-5: 2008 (Eurocode 3) compared with the standard (PN-B-03200: 1990) used previously in Poland, introduces extended rules referring to the computations of the bearing capacity of the plated structural elements including the shear lag effect. The stress distribution in the width flanges is variable. Therefore in the case of the beam with the shear lag effect cannot be calculated by the classic beam theory.In this article a comparison of the results of the calculations of forces distribution, stresses and displacement according to the rule presented in PN-EN 1993 and results of the numerical computations for 3D model (using finite element method) is presented. The elastic shear lag effects, the elastic shear lag effects including effects of the plate buckling and the elastic-plastic shear lag effects including the local instabilities were analysed. The calculations were performed for beams with a small and a large span and an influence of stiffeners was analysed.

scholarly journals A New Approach for Free Vibration Analysis of Thin-Walled Box Girder Considering Shear Lag Effect

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zuolong Luo ◽  
Haoyun Yuan ◽  
Xirong Niu
Keyword(s):  
Boundary Condition ◽  
Free Vibration ◽  
Free Vibration Analysis ◽  
Beam Theory ◽  
Dynamical Response ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Lag Effect ◽  
Thin Walled

The thin-walled box girder (T-WBG) is widely applied in the long-span bridge structures during the past decades due to its lighter self-weight and better mechanical properties. The shear lag effect (SLE), an essential aspect of T-WBG which governs the stress and the deformation, is rather necessary to be revealed properly. The extraordinary issue of T-WBG analysis nowadays is the SLE impact on its dynamical response to external load. This paper proposes an improved finite element method (FEM) to obtain the realistic vibration characteristics of the T-WBG considering the SLE by theory analysis and formula derivation. Firstly, based on the classical plate and shell theory as well as beam theory, the T-WBG was divided into shell subunit for the roof and beam subunit for web and floor, respectively. Secondly, a 3-order polynomial which is consistent with the experiment results was adopted as the axial-displacement interpolation function of the roof subunit, whose nodal displacements parameters were also taken as the basic. Thirdly, the nodal displacement parameters of the web subunit and floor subunit were deduced by the basic according to the principle of deflection consistency. It is shown through a numerical example that the proposed method is much more economical to achieve reasonable accuracy than traditional FEM analysis software when dealing with the free vibration problem of the T-WBG considering the SLE. Besides, it is also observed that the natural frequency values considering the SLE have a trend of decreasing markedly in general, and the influence of SLE on higher-order frequency is more significant than on the lower one under the boundary condition of cantilever supported, while a contrary effect under the boundary condition of simple supported.

Influence of Compression-Flexure to Shear Lag Effect of Box Beam

2011 ◽  
Vol 181-182 ◽  
pp. 857-860 ◽  
Author(s):  
Qiang Su ◽  
Ya Ping Wu
Keyword(s):  
Stiffness Matrix ◽  
Elastic Stiffness ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Finite Element Program ◽  
Box Beam ◽  
Lag Effect ◽  
Element Program ◽  
Box Beams ◽  
Minimum Potential

In this paper, the differential equations of box beams are established based on the principle of minimum potential energy and the variational method. The elastic stiffness matrix and geometric stiffness matrix considering shear lag and compression-flexure effects are induced in this paper. And a finite element program is developed. Then the influence of compression-flexure effects to shear lag effect of box beam is analyzed.

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