Increase of critical flutter wind speed of long-span bridges using tuned mass dampers

1998 ◽  
Vol 73 (2) ◽  
pp. 111-123 ◽  
Author(s):  
M. Gu ◽  
C.C. Chang ◽  
W. Wu ◽  
H.F. Xiang
Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1633
Author(s):  
Yang Ding ◽  
Shuang-Xi Zhou ◽  
Yong-Qi Wei ◽  
Tong-Lin Yang ◽  
Jing-Liang Dong

Wind field (e.g., wind speed and wind direction) has the characteristics of randomness, nonlinearity, and uncertainty, which can be critical and even destructive on a long-span bridge’s hangers, such as vortex shedding, galloping, and flutter. Nowadays, the finite element method is widely used for model calculation, such as in long-span bridges and high-rise buildings. In this study, the investigated bridge hanger model was established by COMSOL Multiphysics software, which can calculate fluid dynamics (CFD), solid mechanics, and fluid–solid coupling. Regarding the wind field of bridge hangers, the influence of CFD models, wind speed, and wind direction are investigated. Specifically, the bridge hanger structure has symmetrical characteristics, which can greatly reduce the calculation efficiency. Furthermore, the von Mises stress of bridge hangers is calculated based on fluid–solid coupling.


2015 ◽  
Vol 100 ◽  
pp. 468-478 ◽  
Author(s):  
Bejoy P. Alduse ◽  
Sungmoon Jung ◽  
O. Arda Vanli ◽  
Soon-Duck Kwon

Author(s):  
Jiunn-Yin Tsay

To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[Formula: see text]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.


2011 ◽  
Vol 383-390 ◽  
pp. 5071-5075
Author(s):  
Su Qi ◽  
Xing Xing Chen ◽  
Qing Xu

Wind-induced vibration of long span bridges mainly as flutter, buffeting and vortex induced vibration. Buffeting and vortex-induced vibration will not cause the devastating destruction of the bridge, while the chatter is the elastic system in the air of self-excited vibration, when the vibration system from the air flow in the absorption of energy and the energy is greater than the energy damping When consumed, they cause divergence of the self-excited aerodynamic flutter vibration. If the critical flutter wind speed is less than in the bridge office potential wind speed, the bridge flutter may occur caused devastating damage. According to modern control theory, a theoretical analysis is conducted on the active control of cable-stayed bridge flutter, it is established that the controlled equation of cable-stayed bridge controlled by a single active mass damper and the motion equation of a single AMD to determine the calculation method of the critical flutter velocity under the controlled status of the cable-stayed bridge. An example shows that a single ADM is a good means to prevent the flutter damage of long-span cable-stayed bridges.


2020 ◽  
Vol 23 (9) ◽  
pp. 1823-1837
Author(s):  
Kun Lin ◽  
Minghai Wei ◽  
Hongjun Liu ◽  
Huafeng Wang

In this article, a two-dimensional Lighthill aerodynamic model is first extended to three-dimensional space, and then combined with the larger Von Karman plate deformation theory, a model for predicting the critical flutter wind speeds of long-span bridges in the primary design is proposed. The predictions of the presented model are compared to the results of wind tunnel tests for five long-span bridges with different main girder section forms. After that, based on the proposed model, the effects of width to span ratio and thickness to span ratio on the critical flutter wind speeds of long-span bridges are investigated. The results show that the differences between the proposed model and wind tunnel tests are only 7%–14%. Therefore, the presented model can assess the flutter wind speed in preliminary design stages of a bridge. The results also reveal that width to span ratios between 1/30 and 1/10 and thickness to span ratios between 1/300 and 1/100 are optimal for long-span bridges.


2011 ◽  
Vol 255-260 ◽  
pp. 4202-4206
Author(s):  
Yue Zhang ◽  
Mi Zhou

The area of mountain ridge accounts for the most part of our country land. With the development of economic construction, more and more long span bridges have been built in the mountainous region of the western in China.. Combining live observed wind with numeric simulation, the wind characteristics on the western gap of valley areas are studied. On the one hand through the self-development processing of the bridge speed data to analyze massive wind observation data, the parameters (such as wind speed profile, turbulence intensity, power spectral density) used as the main basis for calculating wind loads are achieved. On the other hand wind flow around the bridge site as well as the environment around the mountain wind flow, wind speed field and the distribution of turbulent flow, etc is obtained by using CFD technology. Based on the results that is compared with that of numerical simulation by FLUENT, the reliability and efficiency of the program is testified. It would be provided with great theoretical significance and practical engineering value passes through the foregoing study.


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