Effect of uncertainties in wind speed and direction on the fatigue damage of long-span bridges

2015 ◽  
Vol 100 ◽  
pp. 468-478 ◽  
Author(s):  
Bejoy P. Alduse ◽  
Sungmoon Jung ◽  
O. Arda Vanli ◽  
Soon-Duck Kwon
Keyword(s):  
Wind Speed ◽  
Fatigue Damage ◽  
Long Span Bridges ◽  
Long Span

scholarly journals Influence of Wind Speed, Wind Direction and Turbulence Model for Bridge Hanger: A Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1633
Author(s):  
Yang Ding ◽  
Shuang-Xi Zhou ◽  
Yong-Qi Wei ◽  
Tong-Lin Yang ◽  
Jing-Liang Dong
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Wind Field ◽  
Solid Mechanics ◽  
Von Mises Stress ◽  
Long Span Bridges ◽  
High Rise ◽  
Long Span ◽  
Cfd Models ◽  
Von Mises

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.

Feasibility Study of Super-Long Span Bridges Considering Aerostatic Instability by a Two-Stage Geometric Nonlinear Analysis

2020 ◽  
pp. 2150033
Author(s):  
Jiunn-Yin Tsay
Keyword(s):  
Wind Speed ◽  
Nonlinear Analysis ◽  
Two Stage ◽  
Long Span Bridges ◽  
Critical Wind Speed ◽  
Long Span ◽  
Main Cable ◽  
Geometric Nonlinear ◽  
Long Span Bridge ◽  
Geometric Nonlinear Analysis

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.

Study on Cable-Stayed Bridge Flutter Active Control by a Single ADM

2011 ◽  
Vol 383-390 ◽  
pp. 5071-5075
Author(s):  
Su Qi ◽  
Xing Xing Chen ◽  
Qing Xu
Keyword(s):  
Wind Speed ◽  
Active Control ◽  
Active Mass ◽  
Vortex Induced Vibration ◽  
Long Span Bridges ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Excited Vibration ◽  
Active Mass Damper ◽  
Wind Induced Vibration

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.

A predictive critical flutter wind speed modeling for long-span bridges

2020 ◽  
Vol 23 (9) ◽  
pp. 1823-1837
Author(s):  
Kun Lin ◽  
Minghai Wei ◽  
Hongjun Liu ◽  
Huafeng Wang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span ◽  
Aerodynamic Model ◽  
Proposed Model

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.

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