Study of Free Vibration Characteristic of Continuous Box-Girder Based on Hamilton Principle

2013 ◽  
Vol 351-352 ◽  
pp. 476-482 ◽  
Author(s):  
Wang Bao Zhou ◽  
Li Zhong Jiang ◽  
Zhi Huang
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Width Ratio ◽  
Rotational Inertia ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Hamilton Principle ◽  
Lag Effect ◽  
Span Width

Based on Hamilton principle, the differential equation of free vibration and the corresponding boundary conditions of continuous box girder with consideration for the shear lag effect meeting self-equilibrated stress, shear deformation as well as rotational inertia were induced. The ANSYS finite element solutions were compared with the analytical solutions by calculation examples and the validity of the proposed approach was verified. The obtained formulas developed the shear lag theory. Some meaningful conclusions for engineering design were obtained. The contribution of the shear lag effect decreases each order natural frequency of the continuous box-girder, at the same time the higher the order natural frequency is, the greater the influence of shear lag effect on natural frequency of continuous box-girder is. The shear-lag effect of continuous box girder increases when frequency order rises, and increases while span-width ratio decreases.

Influence of Shear Lag and Shear Deformation Effects on Deflection of Composite Box Girder with Corrugated Steel Webs

2013 ◽  
Vol 671-674 ◽  
pp. 985-990 ◽  
Author(s):  
Peng Qiao
Keyword(s):  
Shear Deformation ◽  
Parametric Analysis ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Deformation Effect ◽  
Box Girder ◽  
Composite Girder ◽  
Deflection Coefficient ◽  
Lag Effect ◽  
Span Width

The shear lag and shear deformation effects on deflection of composite girder with corrugated steel webs (CGCSW) was studied. The influence of shear lag and shear deformation effect was expressed by deflection coefficient δ1 and δ2. Parametric analysis within a scope of dimensions of built-in girders was performed, including girder span, width, height, thickness of concrete flange and thickness of steel web. The results show that the deflection coefficient of shear lag effect is approximately directly proportional to square of width-span ratio, while the deflection coefficient of shear deformation effect is related to all parameters. It’s suggested that shear lag effect on CGCSW’s deflection be neglected when width-span ratio is smaller than 1/9, and shear deformation effect should always be considered.

scholarly journals Shear Lag Effect and Accordion Effect on Dynamic Characteristics of Composite Box Girder Bridge with Corrugated Steel Webs

2020 ◽  
Vol 10 (12) ◽  
pp. 4346
Author(s):  
Yuntai Zhang ◽  
Lizhong Jiang ◽  
Wangbao Zhou ◽  
Yulin Feng
Keyword(s):  
Natural Vibration ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Accordion Effect ◽  
Lag Effect ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
The Impact ◽  
Span Width

This study proposed a dynamic characteristic analytical method (ANM) of a composite box girder bridge with corrugated steel web (CBGCSW) by completely considering the impact of shear lag effect and accordion effect of corrugated steel webs. Based on energy principles and variational principles, a vibration differential equation and the natural boundary conditions of a CBGCSW were developed. The analytical calculation formula for solving the vibration differential equation was then obtained. The results calculated using the ANM agreed well with previous experimental results, which validated the correctness of ANM. To demonstrate the superiority of the ANM, the vibration frequencies of several abstract CBGCSWs with varying ratios of span–width, obtained using the elementary beam theory (EBT) and the finite element method (FEM), were compared with those obtained by ANM. The efficacy of the ANM was verified and some meaningful conclusions were drawn which are helpful to relevant engineering design, such as the observation that a higher natural vibration frequency and smaller span–width ratio significantly magnified the shear lag effect of CBGCSW. The first five-order natural vibration frequencies of the CBGCSW were significantly lower than those of the composite box girder bridge with general steel web (CBGGSW), which indicates that the impact of the accordion effect is significant.

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.

Shear lag effect on stress concentration in simply-supported stiffened box girder

2021 ◽  
Vol 183 ◽  
pp. 106715
Author(s):  
Eiki Yamaguchi ◽  
Naoto Kittaka ◽  
Buchit Maho ◽  
Piti Sukontasukkul
Keyword(s):  
Stress Concentration ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Simply Supported ◽  
Lag Effect

scholarly journals The shear-lag effect of composite box girder bridges with corrugated steel webs and trusses

2019 ◽  
Vol 181 ◽  
pp. 617-628 ◽  
Author(s):  
Yiyan Chen ◽  
Jucan Dong ◽  
Tianhua Xu ◽  
Yufeng Xiao ◽  
Ruijuan Jiang ◽  
...  
Keyword(s):  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Lag Effect

Stress concentration and deflection of simply supported box girder including shear lag effect

2008 ◽  
Vol 28 (2) ◽  
pp. 207-220 ◽  
Author(s):  
Eiki Yamaguchi ◽  
Taweep Chaisomphob ◽  
Jaturong Sa-nguanmanasak ◽  
Chartree Lertsima
Keyword(s):  
Stress Concentration ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Simply Supported ◽  
Lag Effect

Shear Lag Effect of Continuous Curved Box Girder with Initial Curvature

2012 ◽  
Vol 538-541 ◽  
pp. 1701-1704
Author(s):  
You Ming Wu ◽  
Yong Jun Lu ◽  
Han Shi
Keyword(s):  
Model Tests ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Finite Segment ◽  
Homogeneous Solutions ◽  
Initial Curvature ◽  
Lag Effect ◽  
Finite Segment Method ◽  
Displacement Patterns

The homogeneous solutions of the governing differential equations for shear lag are used as the displacement patterns of the finite segment are presented. A finite segment model with consideration of initial curvature, bending, torsion and shear lag is established. In addition, the tests of the two-span continuous curved box girder and numerical calculations of the model tests by finite segment method and finite element method are made. The results of the model tests and numerical calculation are consistent with each other. An actual example was given to investigate the shear lag effect of a continuous curved box girder under load. The research results show that the initial curvature has an obvious influence on the shear lag effect of a continuous curved box girder.

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