Variation of aerodynamic coefficients with air flow parameters on long span bridge deck

2016 ◽  
Vol 7 (3) ◽  
pp. 279
Author(s):  
Rohit Kumar Mittal ◽  
Vivek Nandan ◽  
Pabitra Ranjan Maiti
Keyword(s):  
Bridge Deck ◽  
Air Flow ◽  
Aerodynamic Coefficients ◽  
Long Span ◽  
Flow Parameters ◽  
Long Span Bridge

scholarly journals Calculated research of aeroelastic stability of a bridge over the river Ob in Salekhard at the stage of assembling and operation

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Anastasiya Shustikova ◽  
Andrei Kozichev ◽  
Sergei Paryshev ◽  
Konstantin Strelkov
Keyword(s):  
Cfd Simulation ◽  
Load Capacity ◽  
Air Flow ◽  
Lift Coefficient ◽  
High Strength ◽  
Railway Bridge ◽  
Aeroelastic Stability ◽  
Ansys Fluent ◽  
Long Span ◽  
Long Span Bridge

Recently, long span bridge construction has been demanded for development of the regions of the Russian Federation. In terms of economy, it’s useful to build a combined road-railway bridge. Such bridges, generally, constitute a metal cross-cutting girder with carriageways on lower, upper or both zones of the girder. The major advantages of combined bridges are high strength and load capacity, plus cross-cutting to wind load. Focus of this research is a combined road-railway bridge over the Ob river at the stage of assembling and operation. The purpose of the study was to determine the limits of aeroelastic stability of combined road-railway bridge at the stage of assembling and operation using numerical simulation. To better understand the bridges behaviour in air flow, flow around a section model has been researched with CFD simulation in the ANSYS FLUENT. Then based on the given results of the calculations the dependence of the bridge vibrations on wind speed within a specified range is obtained, and also values of drag coefficient Сх, lift coefficient Су and torque coefficient Мz are received. These studies were carried out in the range of angles of attack α = ±3°. The possibility of divergence and galloping was also estimated. The results of the study made it possible to estimate the influence of air flow on combined bridge cross-cutting girder. Overall, the conducted research seems promising for further investigation and development in the field of bridge aeroelasticity.

scholarly journals Deep Learning Based Vehicle Detection and Classification Methodology Using Strain Sensors under Bridge Deck

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5051
Author(s):  
Rujin Ma ◽  
Zhen Zhang ◽  
Yiqing Dong ◽  
Yue Pan
Keyword(s):  
Neural Network ◽  
Bridge Deck ◽  
Vehicle Detection ◽  
Traffic Monitoring ◽  
Transportation Systems ◽  
Strain Sensors ◽  
Long Span ◽  
Long Span Bridge ◽  
Pavement Evaluation ◽  
Close Range

Vehicle detection and classification have become important tasks for traffic monitoring, transportation management and pavement evaluation. Nowadays there are sensors to detect and classify the vehicles on road. However, on one hand, most sensors rely on direct contact measurement to detect the vehicles, which have to interrupt the traffic. On the other hand, complex road scenes produce much noise to consider when to process the signals. In this paper, a data-driven methodology for the detection and classification of vehicles using strain data is proposed. The sensors are well arranged under the bridge deck without traffic interruption. Next, a cascade pre-processing method is applied for vehicle detection to eliminate in-situ noise. Then, a neural network model is trained to identify the close-range following vehicles and separate them by Non-Maximum Suppression. Finally, a deep convolutional neural network is designed and trained to identify the vehicle types based on the axle group. The methodology was applied in a long-span bridge. Three strain sensors were installed beneath the bridge deck for a week. High robustness and accuracy were obtained by these algorithms. The methodology proposed in this paper is an adaptive and promising method for vehicle detection and classification under complex noise. It would serve as a supplement to current transportation systems and provide reliable data for management and decision-making.

scholarly journals Steady-Suction-Based Flow Control of Flutter of Long-Span Bridge

2020 ◽  
Vol 10 (4) ◽  
pp. 1372
Author(s):  
Jian Zhan ◽  
Hongfu Zhang ◽  
Zhiwen Liu ◽  
Huan Liu ◽  
Dabo Xin ◽  
...  
Keyword(s):  
Flow Control ◽  
Bridge Deck ◽  
Control Method ◽  
Control Device ◽  
Maximal Increase ◽  
Long Span ◽  
Suction Control ◽  
Long Span Bridge ◽  
Bridge Model ◽  
Section Model

The present wind tunnel study focuses on the effects of the steady-suction-based flow control method on the flutter performance of a 2DOF bridge deck section model. The suction applied to the bridge model was released from slots located at the girder bottom. The suction rates of all slots along the span were equal and constant. A series of test cases with different combinations of suction slot positions, suction intervals, and suction rates were studied in detail for the bridge deck model. The experimental results showed that the steady-suction-based flow control method could improve the flutter characteristics of the bridge deck with a maximal increase in the critical flutter speed of up to 10.5%. In addition, the flutter derivatives (FDs) of the bridge deck with or without control were compared to investigate the fundamental mechanisms of the steady-suction-based control method. According to the results, installing a suction control device helps to strengthen aerodynamic damping, which is the primary cause for enhanced flutter performance of bridge decks.

scholarly journals Application of Spatial Structures in Bridges Deck

2015 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Mohammad Hossein Taghizadeh ◽  
Alaeddin Behravesh
Keyword(s):  
Spatial Structure ◽  
Bridge Deck ◽  
Motor Vehicles ◽  
Spatial Structures ◽  
Environmental Aspects ◽  
Long Span ◽  
Long Span Bridge ◽  
New Material ◽  
Live Loads ◽  
Is Design

Spatial structure is a truss-like, lightweight and rigid structure with a regular geometric form. Usually from these structures is used in covering of long-span roofs. But these structures due to the lightness, ease and expedite of implementation are a suitable replacement for bridge deck. However steel and concrete is commonly used to build bridge deck, but heavy weight of steel and concrete decks and impossibility of making them as long-span bridge deck is caused engineers to thinks about new material that besides lightness and ease of implementation, provide an acceptable resistance against applied loads including both dead load and dynamic load caused by the passage of motor vehicles. Therefore, the purpose of this paper is design and analysis bridge deck that’s made of double-layer spatial frames compared with steel and concrete deck. Then allowable deflections due to dead and live loads, weight of bridge in any model and also economic and environmental aspects of this idea is checked. As a result, it can be said that the use of spatial structures in bridge deck is lead to build bridge with long spans, reducing the material and consequently reducing the structural weight and economic savings. For geometric shape of the spatial structure bridge is used of Formian 2.0 software and for analysis of bridges is used of SAP2000 with finite element method (FEM).

Investigation of edge fairing shaping effects on aerodynamic response of long-span bridge deck by unsteady RANS

2016 ◽  
Vol 16 (4) ◽  
pp. 888-900 ◽  
Author(s):  
Md. Naimul Haque ◽  
Hiroshi Katsuchi ◽  
Hitoshi Yamada ◽  
Mayuko Nishio
Keyword(s):  
Bridge Deck ◽  
Long Span ◽  
Long Span Bridge ◽  
Unsteady Rans
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