scholarly journals Strong wind characteristics and dynamic response of a long-span suspension bridge during a storm

2018 ◽  
Vol 172 ◽  
pp. 116-138 ◽  
Author(s):  
Aksel Fenerci ◽  
Ole Øiseth
Keyword(s):  
Dynamic Response ◽  
Suspension Bridge ◽  
Strong Wind ◽  
Long Span ◽  
Wind Characteristics

Probabilistic Fatigue Damage Analysis of Long Span Suspension Bridge Due to Wind Induced Buffeting

2020 ◽  
Vol 980 ◽  
pp. 275-281
Author(s):  
Hu Jun
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Time History ◽  
Suspension Bridge ◽  
Wind Load ◽  
Strong Wind ◽  
Fatigue Reliability ◽  
Long Span ◽  
Fatigue Damage Analysis ◽  
Fluctuating Wind

In order to consider the fluctuating wind load induced fatigue problem of long span suspension bridge, fatigue reliability formula is modified by assuming the fatigue life is accord with the weibull distribution. Based on the accurate bridge buffeting analysis of time history, the stress time history of components of a suspension bridge in east sea China is simulated, and then the fatigue damages and reliabilities are calculated. The results indicate that the main cables and hangers have enough fatigue reliability under the fluctuating wind load, the fatigue failure will not occur; the stiffening girder has larger fatigue damage, under 40 / (m.s-1) mean wind speed action, the girder of mid-support section’s average fatigue life is only 3.103 years, so the girder’s damage under strong wind action should be taken seriously.

Comparison of wind characteristics at different heights of deep-cut canyon based on field measurement

2019 ◽  
Vol 23 (2) ◽  
pp. 219-233 ◽  
Author(s):  
Jingyu Zhang ◽  
Mingjin Zhang ◽  
Yongle Li ◽  
Chen Fang
Keyword(s):  
Wind Speed ◽  
Vertical Direction ◽  
Suspension Bridge ◽  
Longitudinal Direction ◽  
Longitudinal Component ◽  
Attack Angle ◽  
Gust Factor ◽  
Long Span ◽  
Wind Characteristic ◽  
Wind Characteristics

The typical U-shaped deep-cut canyon is widely distributed in the western mountainous areas of China, especially in Sichuan province and Yunnan province. The deep-cut canyon has the characteristics of the high drop in elevation, high-temperature difference, and complex wind environment. A 50 m high meteorological mast with a total of eight anemometers was erected in such topography, and a long-span suspension bridge will be constructed in the area where the meteorological mast is located. Based on the long-term monitor data, the wind characteristic parameters including average and fluctuating wind characteristics and coherence between different heights are investigated. The results are as follows. The dominant wind direction which depends on the topography is north–south. The attack angle of wind is mainly less than zero, and its probability distribution obeys the hypothetical Gaussian distribution. Both the increases in height of anemometer and in wind speed reduce the dispersion of the attack angle of wind. The gust factor has a similar change law of attack angle of wind. Turbulence intensities are affected by the height of the anemometer and the wind speed, and they are different from the recommended value of China Codes. In terms of turbulence integral length scale, the value increases with an increase in the height of the anemometer in the same component. The largest value occurs in the longitudinal direction and the smallest occurs in the vertical direction at the same level. The coherence between any two locations is relatively strong, and the longitudinal component is stronger than others. The measured wind power spectrum for longitudinal, lateral, and vertical wind in deep-cut canyon fits the von Kármán model better.

scholarly journals Dynamic Coupling Analysis of Vehicle-Bridge System for Long-Span Suspension Bridge Based on Backpropagation Neural Network Method

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zuolong Luo ◽  
Xiaobo Zheng ◽  
Haoyun Yuan ◽  
Xirong Niu
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Dynamic Response ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Dynamic Coupling ◽  
Coupling Analysis ◽  
Long Span ◽  
Coupling System ◽  
Bridge System

As the suspension bridge structures become more flexible and the forms of the vehicle load become more diverse, the dynamic coupling problem of the vehicle-bridge system has become gradually prominent in long-span suspension bridges, resulting in an increase in accuracy and efficiency requirements for dynamic coupling analysis of the vehicle-bridge system. Conventional method such as finite element method (FEM) for dynamic coupling analysis of vehicle-bridge system often requires separate iteration of vehicle system and bridge system, and the contact and coupling interactions between them are used as the link for convergence inspection, which is too computationally intensive and time-consuming. In addition, the dynamic response of the vehicle-bridge coupling system obtained by FEM cannot be expressed explicitly, which is not convenient for engineering application. To overcome these drawbacks mentioned above, the backpropagation (BP) neural network technology is proposed to the dynamic coupling analysis of the vehicle-bridge system of long-span suspension bridges. Firstly, the BP neural network was used to approximate the dynamic response of the suspension bridge in the vehicle-bridge coupling system, and the complex finite element analysis results were thus explicitly displayed in the form of a mathematical analytical expression. And then the dynamic response of the suspension bridge under vehicle load was obtained by using a dynamic explicit analysis method. It is shown through a numerical example that, compared with FEM, the proposed method is much more economical to achieve reasonable accuracy when dealing with the dynamic coupling problem of the vehicle-bridge system. Finally, an engineering case involving a detailed finite element model of a long-span suspension bridge with a main span of 1688 m is presented to demonstrate the applicability and efficiency under the premise of ensuring the approximation accuracy, which indicates that the proposed method provides a new approach for dynamic coupling analysis of the vehicle-bridge system of long-span suspension bridges.

Study on Wind Characteristics of Runyang Suspension Bridge Based on Long-Term Monitored Data

2016 ◽  
Vol 16 (04) ◽  
pp. 1640019 ◽  
Author(s):  
Hao Wang ◽  
Tong Guo ◽  
Tian-You Tao ◽  
Ai-Qun Li
Keyword(s):  
Wind Speed ◽  
Turbulence Intensity ◽  
Suspension Bridge ◽  
Wind Data ◽  
Strong Wind ◽  
Wind Rose ◽  
Integral Scale ◽  
Current Specification ◽  
Wind Characteristics

The slender and flexible characteristics make Runyang Suspension Bridge (RSB) sensitive to the wind actions. In order to obtain reliable statistical wind characteristics and monitor the wind environment at the bridge site, two anemometers are included in the structural health monitoring system (SHMS) to collect extensive wind data. In this paper, the recorded real-time wind data are analyzed in detail to acquire the wind rose diagram, mean wind speed and direction, turbulence intensity, turbulence integral scale, and power spectral density (PSD). Three strong wind events including Typhoon Matsa, Typhoon Khanun and Northern wind are comparatively analyzed to show the inhomogeneous wind characteristics. And the measured wind characteristics are compared with the recommended values in current specification of China. The analytical results show that the wind speed and wind direction at RSB site are greatly influenced by the subtropical monsoon climate and typhoon climate. And the traditional known rules concerning turbulence intensity are not proper for strong winds, while the rules can be validated by long-term monitored data. Meanwhile, the recommended values of turbulence integral scale by current specification are suitable for long-term monitored wind, but the adaptability to strong wind is still defective. In addition, the measured along-wind spectra match generally well with the commonly used PSDs of turbulence. However, more researches are still needed to refine current PSDs of turbulence to perfectly satisfy with the measured spectrum. The conclusions can provide references for the wind-resistant analysis of RSB and structures in similar areas.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

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