scholarly journals NUMERICAL SIMULATION OF AERODYNAMIC STABILITY OF LONG-SPAN BRIDGES

2021 ◽  
pp. 106-114
Author(s):  
A. V. Kozlov ◽  
V. S. Safronov
Keyword(s):  
Software Systems ◽  
Wind Flow ◽  
Aerodynamic Stability ◽  
Volga River ◽  
Disturbing Force ◽  
Long Span Bridges ◽  
Long Span ◽  
Bridge Structures ◽  
Bridge Spans ◽  
The City

Statement of the problem. The aim of the work is to simulate the resonant vibrations of the continuous beam span of the bridge in the direction perpendicular to the wind flow by the finite element method. The article deals with a non-standard situation that arose on May 20, 2010 on the bridge over the Volga River in the city of Volgograd.Results. As a result, an effective algorithm for calculating the aerodynamic stability of large-span bridge structures was developed using one of the most widespread software systems in Russia and neighboring countries - "Lira-SAPR". Recommendations for the selection and modeling of dampers are given. Conclusions. The developed algorithm makes it possible to numerically describe the disturbing force of periodic breakdown of wind flow vortices, which causes resonant oscillations of bridge spans, to apply this force to the design model in Lira-SAPR, and to obtain parameters that make it possible to assess the stress-strain state of the system during oscillations and to select the optimal characteristics of the damping devices.

scholarly journals Ensuring the aerodynamic stability of the long-span bridges through studies in the wind tunnel

2018 ◽  
Vol 245 ◽  
pp. 02001 ◽  
Author(s):  
Evgenii Khrapunov ◽  
Sergei Solovev
Keyword(s):  
Wind Tunnel ◽  
Design Process ◽  
Aerodynamic Characteristics ◽  
Elastic Instability ◽  
Experimental Facility ◽  
Bridge Design ◽  
Aerodynamic Stability ◽  
Long Span Bridges ◽  
Long Span ◽  
Main Ideas

The main ideas of the aerodynamic studies of large bridges are presented in present paper. Main types of aero-elastic instability for bridges with spans over 100 meters are considered. A two-step modeling approach is presented. At the first stage, the aerodynamic characteristics of the span fragment are considered, at the second.stage the characteristics of the whole bridge. Methods for investigation of bridge oscillations in a special-purpose experimental facility – the Landscape Wind Tunnel – are described. Examples of tests with elastic similar models of bridges are given, and measurements to mitigate dangerous oscillations early in the bridge design process are described.

Numerical Simulation of Wind-Driven Rain on a Long-Span Bridge

2019 ◽  
Vol 19 (12) ◽  
pp. 1950149
Author(s):  
Shenghong Huang ◽  
Qiusheng Li ◽  
Man Liu ◽  
Fubin Chen ◽  
Shun Liu
Keyword(s):  
Numerical Simulation ◽  
Wind Engineering ◽  
Multiphase Model ◽  
Rain Intensity ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Extreme Rain ◽  
Section Model ◽  
Bridge Spans

Wind-driven rain (WDR) and its interactions with structures is an important research subject in wind engineering. As bridge spans are becoming longer and longer, the effects of WDR on long-span bridges should be well understood. Therefore, this paper presents a comprehensive numerical simulation study of WDR on a full-scale long-span bridge under extreme conditions. A validation study shows that the predictions of WDR on a bridge section model agree with experimental results, validating the applicability of the WDR simulation approach based on the Eulerian multiphase model. Furthermore, a detailed numerical simulation of WDR on a long-span bridge, North Bridge of Xiazhang Cross-sea Bridge is conducted. The simulation results indicate that although the loads induced by raindrops on the bridge surfaces are very small as compared to the wind loads, extreme rain intensity may occur on some windward surfaces of the bridge. The adopted numerical methods and rain loading models are validated to be an effective tool for WDR simulation for bridges and the results presented in this paper provide useful information for the water-erosion proof design of future long-span bridges.

Effect of Turbulence on the Aerodynamic Stability of Long Span Bridges

2013 ◽  
Vol 639-640 ◽  
pp. 452-455 ◽  
Author(s):  
Chun Guang Li ◽  
Zheng Qing Chen ◽  
Zhi Tian Zhang
Keyword(s):  
Wind Tunnel Test ◽  
Grid Turbulence ◽  
Aerodynamic Stability ◽  
Rectangular Section ◽  
Long Span Bridges ◽  
Long Span ◽  
Turbulence Flow ◽  
Turbulence Effect ◽  
Suspended Bridge ◽  
Derivatives Of

The study deals with the problem of turbulence effect on the instability of a long span suspended bridge. Wind tunnel test of three representative section models have been carried out in four type of passive grid turbulence flow to clarify the effect of turbulence intensity and turbulence scales. It was found that the turbulence has little effect on the derivatives of those streamlined deck sections, while it exhibits significant stabilizing effect on the bluff rectangular section prism. The loss of spanwise correlation may not be the main reasons induce the change of flutter stability in turbulence.

Deformability and Aerodynamic Stability as Limits in Long Span Bridges

2001 ◽  
Vol 84 (8) ◽  
pp. 58-65
Author(s):  
Domenico Bruno ◽  
Mario Como ◽  
Antonio Grimaldi ◽  
Angelo Leonardi
Keyword(s):  
Aerodynamic Stability ◽  
Long Span Bridges ◽  
Long Span

Structural Type Selection for Long-Span Bridges in Mountain Area

2012 ◽  
Vol 256-259 ◽  
pp. 1596-1600
Author(s):  
Dong Liang ◽  
Chang Rong Yao ◽  
Sai Zhi Liu
Keyword(s):  
Conceptual Design ◽  
Structural Type ◽  
Mountainous Area ◽  
Construction Technology ◽  
Mountain Area ◽  
Long Span Bridges ◽  
Long Span ◽  
Type Selection ◽  
Geological Conditions ◽  
Bridge Structures

As the western region is a mountainous area with geology complicated geological conditions, the proportion of bridges and tunnels is bigger. Based on the characteristic of mountainous route and long-span bridges, this paper discussed the conceptual design of mountainous bridges. Firstly, this paper analyzes the characteristic of mountainous long-span bridges and proposed some fundamental principles to design long-span bridges. After the comparison of the main bridge structures, the paper points out that the designer should select the best programs considering hydrological, geological, geomorphology, construction technology, transportation , geographical environment and social environment. The purpose of this paper is to give reference for the conceptual design of mountainous long-span bridges.

Simulation of Vortex-Induced Vibration of Long-Span Bridges: A Nonlinear Normal Mode Approach

2018 ◽  
Vol 18 (11) ◽  
pp. 1850136 ◽  
Author(s):  
Kun Xu ◽  
Yaojun Ge ◽  
Lin Zhao ◽  
Xiuli Du
Keyword(s):  
Normal Mode ◽  
Structural Equation ◽  
Closed Form Expression ◽  
Combination Strategy ◽  
Vortex Induced Vibration ◽  
Long Span Bridges ◽  
Long Span ◽  
Bridge Structures ◽  
Finite Element Procedure ◽  
Nonlinear Normal

Due to the lack of analytic technique for simulating the vortex-induced vibration (VIV) of long-span bridges, a combination of the VIV semi-empirical model with the structural equation of motion is widely employed to calculate the responses of bridge structures. However, the applicability of this method has seldom been investigated before. In this study, the theoretical defects of the conventional combination strategy (i.e. the finite element procedure or the linear normal mode procedure, LNM) are first discussed, a more theoretically reliable approach (the nonlinear norm mode approach, NNM) is then proposed, and the closed-form expression for the NNM of the VIV system is derived. The accuracy of the proposed method is further illustrated by two case studies. This new approach offers a theoretically reliable tool for analyzing the VIV of long-span bridges. It can also be applied to the process of VIV fatigue analysis or control strategy optimization.

Field Investigation and Wind-Environment Numerical Simulation of Cable-Stayed Bridge Site in the West Midlands Region

2011 ◽  
Vol 255-260 ◽  
pp. 4202-4206
Author(s):  
Yue Zhang ◽  
Mi Zhou
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Field Investigation ◽  
Wind Flow ◽  
Observation Data ◽  
Bridge Site ◽  
Wind Speed Profile ◽  
Long Span Bridges ◽  
Long Span ◽  
The One

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.

Effects of guardrails on wind environment for vehicles and aerodynamic stability for bridges with box girders

2020 ◽  
pp. 136943322095682
Author(s):  
Junjie Guo ◽  
Haojun Tang ◽  
Yongle Li ◽  
Zewen Wang
Keyword(s):  
Flow Field ◽  
Suspension Bridge ◽  
Mountainous Areas ◽  
Box Girders ◽  
Aerodynamic Stability ◽  
Wind Environment ◽  
Long Span Bridges ◽  
Long Span ◽  
Strong Winds ◽  
Extreme Winds

Normally strong winds in mountainous areas possess potential threats to the safety of vehicles travelling over the long-span bridges. Generally, decreasing the porosity of the guardrails could improve wind environment for vehicles, while the changed flow field around the bridge’s girder may weaken the structural aerodynamic stability simultaneously. To solve the two seemingly contradictory issues, such a long-span suspension bridge in mountainous areas is taken as the case study, and the guardrails are optimized with different schemes. The effects on wind environment for vehicles under normal traffic conditions are first studied by computational fluid dynamics (CFD) simulations. The further effects on the aerodynamic stability of the bridge under extreme winds are then determined by wind tunnel tests, and the observed non-divergent flutter is explainedbythe change in dynamic flow field. Results show that reducing the porosity of guardrails does improve the wind environment above the bridge deck, and the improvement on wind environment increases with the increase in angle of attack. After closing the guardrails completely, however, the girder appears non-divergent vibration different from the linear theoretical flutter when the critical wind speed is exceeded. The different post-flutter behaviors at different angles of attack are mainly related to the synchronization condition between the movement of vortex and the motion of the girder.

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