The Experts below are selected from a list of 4155 Experts worldwide ranked by ideXlab platform
Wenli Chen - One of the best experts on this subject based on the ideXlab platform.
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review of the excitation mechanism and aerodynamic flow control of vortex induced vibration of the Main Girder for long span bridges a vortex dynamics approach
Journal of Fluids and Structures, 2021Co-Authors: Donglai Gao, Zhi Deng, Wenhan Yang, Wenli ChenAbstract:Abstract Two vortex-induced vibration (VIV) events of the Main Girder of long-span bridges successively happened on the Yingwuzhou suspension bridge and Humen suspension bridge in China, 2020, and drew public attention. Especially for the Humen suspension bridge, the amplitude of VIV was so notable that the traffic was closed for 10 days. Generally, VIV is sensitive to the structural and ambient issues and large-amplitude VIV is unacceptable for engineering structures as it could result in potential fatigue failure of some key joint components. Therefore, it is of great significance to explore the excitation mechanism of VIV and develop effective methods to mitigate excessive vibration of Main-Girders. From the perspective of vortex dynamics, we present a selective review of recent progress on the mechanism of VIV occurred in long-span bridges and aerodynamic countermeasures to attenuate the VIV amplitude. Notwithstanding the VIV mechanism of Girders has not been thoroughly clarified, it is generally accepted that VIV rises from the unsteady vortex shedding from the Main Girder. Besides, the flow control methods, which are proposed to manipulate the surrounding flow patterns around the Girder, are also focused in this review. Some perspectives are finally presented for future studies in fluid–structure interaction and aerodynamic vibration mitigation of long-span bridges.
Wenhan Yang - One of the best experts on this subject based on the ideXlab platform.
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review of the excitation mechanism and aerodynamic flow control of vortex induced vibration of the Main Girder for long span bridges a vortex dynamics approach
Journal of Fluids and Structures, 2021Co-Authors: Donglai Gao, Zhi Deng, Wenhan Yang, Wenli ChenAbstract:Abstract Two vortex-induced vibration (VIV) events of the Main Girder of long-span bridges successively happened on the Yingwuzhou suspension bridge and Humen suspension bridge in China, 2020, and drew public attention. Especially for the Humen suspension bridge, the amplitude of VIV was so notable that the traffic was closed for 10 days. Generally, VIV is sensitive to the structural and ambient issues and large-amplitude VIV is unacceptable for engineering structures as it could result in potential fatigue failure of some key joint components. Therefore, it is of great significance to explore the excitation mechanism of VIV and develop effective methods to mitigate excessive vibration of Main-Girders. From the perspective of vortex dynamics, we present a selective review of recent progress on the mechanism of VIV occurred in long-span bridges and aerodynamic countermeasures to attenuate the VIV amplitude. Notwithstanding the VIV mechanism of Girders has not been thoroughly clarified, it is generally accepted that VIV rises from the unsteady vortex shedding from the Main Girder. Besides, the flow control methods, which are proposed to manipulate the surrounding flow patterns around the Girder, are also focused in this review. Some perspectives are finally presented for future studies in fluid–structure interaction and aerodynamic vibration mitigation of long-span bridges.
Qinghe Wang - One of the best experts on this subject based on the ideXlab platform.
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numerical and theoretical analysis of spatial shear lag effect in through wide box bowstring arch bridge Main Girder
Structures, 2021Co-Authors: Jihe Zhao, Longsheng Bao, Lei Dong, Qinghe WangAbstract:Abstract The shear lag of the box Girder section of a wide box bowstring arch bridge was investigated in this study. The finite element analysis software Midas Civil was used to discretize the bridge into separate entities, establish its spatial model, and analyze the law of shear lag effect in the longitudinal direction during the Main construction stage and the completion stage separately. The shear lag effect is more prominent at certain key points due to the influence of the tension of the boom and the weight of the arch foot during the construction stage. After the bridge is completed, the axial pressure of the arch foot drives the shear lag effect near the midpoint of the Main Girder section to its maximum; the axial force is transmitted along the longitudinal bridge direction in a V shape along which it gradually decreases. Under the action of uniformly distributed load, the cross-section of the box Girder near the middle fulcrum is affected by the axial force of the arch foot; there is both a positive and negative shear lag effect. Under the eccentric load, the positive and negative shear lag effects appear simultaneously at the end fulcrum. The shear lag coefficient is higher in the web on the eccentric load side than the non-load side. There is obvious and widely fluctuating positive/negative shear lag effect in the vicinity of the middle fulcrum. There is significant tensile stress on the roof under the action of the middle fulcrum. The cross-sectional stress of a single-box seven-cell box Girder under compression-bending load action was analyzed according to the finite element analysis results. The stress was decomposed into a superposition of bending moment action and axial force action. The shear lag coefficient λ M under the action of bending moment was also solved via energy variation method. Assuming that the axial force is only borne by the compressed area, the shear lag coefficient λ N under the action of the axial force was obtained; λ M and λ N were superimposed to determine the comprehensive shear lag effect coefficient λ .
Moonyoung Kim - One of the best experts on this subject based on the ideXlab platform.
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elastic stability behavior of self anchored suspension bridges by the deflection theory
International Journal of Structural Stability and Dynamics, 2017Co-Authors: Myungrag Jung, Minjung Jang, Mario M Attard, Moonyoung KimAbstract:To investigate the elastic buckling behavior of self-anchored suspension bridges subjected to proportionally increasing dead loads, a new stability procedure is proposed based on the deflection theory. For this purpose, a finite element buckling analysis is performed using the initial state solution based on the unstrained length method (ULM) (Ref. 1). The finite element solutions are compared with those by the deflection theory. It is shown that both the Main Girder and tower of the self-anchored suspension bridge are under compression, but their fundamental buckling modes are tower-dominant. Importantly, it is observed that local buckling within the Main Girder supported by hangers occurs without any geometric change of the Main cable, in the higher buckling modes of the self-anchored suspension bridge.
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nonlinear analysis methods based on the unstrained element length for determining initial shaping of suspension bridges under dead loads
Computers & Structures, 2013Co-Authors: Myungrag Jung, Moonyoung KimAbstract:Two nonlinear analysis methods are newly presented for finding the initial shape of suspension bridges under dead load. For this, the extended tangential stiffness matrices of the nonlinear frame element as well as the elastic catenary cable element are derived by adding unstrained element lengths to the unknown. A G.TCUD (generalized target configuration under dead loads) method and an unstrained element length method are then proposed to get the minimized bending moment as well as to remove both lateral and axial deformations in the Main Girder and the tower. Finally the accuracy and effectiveness of the proposed schemes are demonstrated through two numerical examples.
Yao Fahai - One of the best experts on this subject based on the ideXlab platform.
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feasibility analysis of erection of integral steel truss Girder blocks of Main bridge of wuhan tianxingzhou changjiang river rail cum road bridge
Bridge Construction, 2007Co-Authors: Yao FahaiAbstract:The Main bridge of Wuhan Tianxingzhou Changjiang River Rail-cum-Road Bridge is a cable-stayed bridge with double pylons and triple cable planes and the Main Girder of the bridge is a slab and truss composite Girder composed of three trusses that are to be erected by the integral truss Girder block method.In this paper,the feasibility of erection of the steel truss Girder by the method is analyzed.
