scholarly journals Monitoring, intelligent perception and early warning of vortex-induced vibration of suspension bridge

2021 ◽  
Author(s):  
Danhui Dan ◽  
Houjin Li
Keyword(s):  
Real Time ◽  
Hilbert Transform ◽  
Early Warning ◽  
Single Mode ◽  
Suspension Bridge ◽  
Monitoring Data ◽  
Vortex Induced Vibration ◽  
The Real ◽  
Whole Process ◽  
Service Period

Vortex-induced vibration(VIV) is a serious problem of suspension bridges and other long-span bridges during the service period. It can cause the excessive amplitude of the structure under low wind speed, which not only affects the driving comfortableness and safety but also makes the structure face the risk of fatigue failure. The previous research on the identification and evaluation of bridge VIV events during the service period is based on the offline batch processing and analysis of monitoring data, which can not realize real-time perception, calculation, and early warning online. In this paper, according to the vibration characteristics of single-mode sinusoidal-like vibration of engineering structure during VIV, an intelligent monitoring and early warning method for VIV of suspension bridge based on recursive Hilbert transform is proposed. Firstly, the real-time acceleration integral algorithm is used to realize the real-time calculation from the acceleration monitoring data to the dynamic displacement of the stiffening beam, and then the recursive Hilbert transform is used to obtain the real-time analytical signal of the structural displacement during VIV; based on its single-mode near-circular trajectory characteristic, the VIV index and the real-time analysis method are proposed to characterize the development trend of VIV events. This online extraction algorithm can realize the first time warning and the whole process tracking and perception of VIV events. Furthermore, this article also provides a real-time online identification method of key motion parameters such as the instantaneous frequency, phase and amplitude of the structure during VIV, which lays a foundation for real-time monitoring of the whole process of VIV and further evaluation and management decision-making. The accuracy, reliability and engineering feasibility of the proposed method are verified by numerical simulation and VIV monitoring data of a real bridge.

The Research into the Visual and Simulated System of the Orbiting Satellite

2013 ◽  
Vol 753-755 ◽  
pp. 1324-1327
Author(s):  
Jia Qiang Dong
Keyword(s):  
Real Time ◽  
Time Management ◽  
Simulation System ◽  
Earth Model ◽  
Virtual Training ◽  
The Real ◽  
Whole Process ◽  
Network Training ◽  
The Earth ◽  
Simulated System

The visual and simulated system of the orbiting satellite based on the OpenGL technology is designed and realized in this paper, in which a visualization platform of the satellite in-orbit running is constructed. The simulation system has constructed the satellite model and the earth model by making use of 3DS MAX technology, and achieved the visualization of satellite in-orbit-running, the visualization of the communication route and of the overlay effect. At the same time, which has realized the access to the database of the orbiting satellite by means of ADO technology .The practices have proven that the system can simulate the whole process of satellite in-orbit-running in real-time, and provides the assistant support platform of the real-time management and decision. Apart from this, the system provides the network training of the space forces with virtual training platform. It is of great significance to construct the virtual battlefield simulation system.

scholarly journals Construction and application of the 3D geo-hazard monitoring and early warning platform

2021 ◽  
Vol 13 (1) ◽  
pp. 1040-1052
Author(s):  
Dunlong Liu ◽  
Lei He ◽  
Qian Wu ◽  
Yan Gao ◽  
Bin Liu ◽  
...  
Keyword(s):  
Real Time ◽  
Information Management ◽  
Early Warning ◽  
Relevant Information ◽  
Geographical Information ◽  
Monitoring Data ◽  
Real Time Monitoring ◽  
Uniform Resource Identifier ◽  
Service Architecture ◽  
Monitoring And Early Warning

Abstract As geo-hazard monitoring data increases in category and size, conventional geo-hazard information management systems, without a unified integration framework and visualized data display, are unable to satisfy the urgent needs of geo-hazard information management. Representational State Transfer (REST), a resource-centered service architecture, abstracts data and services into resources for unified Uniform Resource Identifier access, enabling it to take full advantage of HTTP with great flexibility and scalability. Based on the REST service architecture, this paper constructs a 3D geo-hazard monitoring and early warning platform with sound service compatibility and scalability by integrating geographical information, real-time monitoring data, and early warning models into the 3D Digital Earth framework. The platform displays topography, stratum lithology, and relevant information, as well as real-time monitoring data in a 3D visual, and provides early warning services for geo-hazards through access to real-time early warning models. As a result, it is capable of providing comprehensive information management, monitoring, and early warning of multiple geo-hazards, aiding decision-making in disaster prevention and mitigation, and enhancing the information level of geo-hazard prevention and mitigation work.

Research and Application of Real-Time Remote Monitoring and Early Warning System of Source Water Quality

2013 ◽  
Vol 779-780 ◽  
pp. 1408-1413
Author(s):  
Shu Yuan Li ◽  
Jian Hua Tao ◽  
Lei Yu
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Early Warning ◽  
Remote Monitoring ◽  
Early Warning System ◽  
Warning System ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
The Real ◽  
Monitoring And Early Warning

Drinking water sources play an important role in assurance of life safety, normal production and social stability. In this paper, a real-time remote water quality monitoring and early warning system has been developed. The paper concentrates on the system architecture and key techniques of the real-time water quality monitoring and early warning. The implementation of the system by advanced water quality sensor techniques, wireless transmission, databases and water quality modeling is retraced in detail. It can be applied to the real-time remote monitoring of water quality and decision support for water pollution incidents.

Early Warning of Low Frequency Oscillation and Analysis of its Related Issues

2012 ◽  
Vol 433-440 ◽  
pp. 7465-7470
Author(s):  
Chao Dong ◽  
Di Chen Liu ◽  
Zhen Chuan Du ◽  
Qing Fen Liao ◽  
Lei Yun ◽  
...  
Keyword(s):  
Real Time ◽  
Early Warning ◽  
Low Frequency ◽  
Local Maximum ◽  
Weak Links ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
The Real ◽  
Time Dynamic ◽  
Interconnected Power System

This paper set up the model of power transmissive observational section and put forward the real-time tracking method of power angle curve in steady state which could be used to identify and focus on monitoring the weak links, then to take early warnings of low frequency oscillation. On the dynamic situation of system been disturbed, we extracted the real-time dynamic damping value of the observational section, calculated its fitting curve of local maximum points and took the slope of curve as the criteria, in order to achieve early warning of low frequency oscillation under multiple disturbances in the interconnected power system.

scholarly journals Research and Application of a Smart Monitoring System to Monitor the Deformation of a Dam and a Slope

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yongfei Wang ◽  
Dingbin Shen ◽  
Jiankang Chen ◽  
Liang Pei ◽  
Yanling Li ◽  
...  
Keyword(s):  
Real Time ◽  
Mean Square Error ◽  
Monitoring System ◽  
Deformation Monitoring ◽  
Monitoring Data ◽  
Large Field ◽  
Maximum Relative Error ◽  
Mean Square ◽  
Integrated Monitoring ◽  
The Real

Deformation monitoring is one of the most important means of providing feedback to ensure the safety of projects. Problems plague the existing automatic monitoring system, such as the small monitoring range of monitoring devices, the inadequate field safety protection, and the low accuracy under extreme weather conditions. These problems greatly reduce the real time and reliability of deformation monitoring data and restrict the real-time intelligent control of engineering safety risk. In this paper, a multitype instrument-integrated monitoring system based mainly on the total positioning station (TPS) and supplemented by the Global Navigation Satellite System (GNSS) was promoted with the methods of large field angle, data complementation, environmental perception and judgment, automatic status control, and baseline calibration-meteorological fusion correction. The application results of Pubugou Station show that the averages of mean square error of points (APMSE) for the dam are 0.41∼1.65 mm and the averages of mean square error of height (AHMSE) are 0.42∼0.89 mm. Moreover, the APMSE and AHMSE for the slope are less than 3 mm. The maximum relative error of the TPS and GNSS data compared with the artificial monitoring data is less than 10%. Besides, the system has good overall performance and is of significant comprehensive benefits. The proposed system realizes the all-weather real-time monitoring of deformation and enhances the emergency response capability of special conditions in dams during the operation period.

scholarly journals Automatic Identification of Bridge Vortex-Induced Vibration Using Random Decrement Method

2019 ◽  
Vol 9 (10) ◽  
pp. 2049 ◽  
Author(s):  
Zhiwen Huang ◽  
Yanzhe Li ◽  
Xugang Hua ◽  
Zhengqing Chen ◽  
Qing Wen
Keyword(s):  
Turbulence Intensity ◽  
Novelty Detection ◽  
Suspension Bridge ◽  
Underlying Mechanism ◽  
Monitoring Data ◽  
Automatic Identification ◽  
Suspension Bridges ◽  
Vortex Induced Vibration ◽  
Random Decrement Technique ◽  
Random Decrement

Vortex-induced vibration (VIV) has been occasionally observed on a few long-span steel box-girder suspension bridges. The underlying mechanism of VIV is very complicated and reliable theoretical methods for prediction of VIV have not been established yet. Structural health monitoring (SHM) technology can provide a large amount of data for further understanding of VIV. Automatic identification of VIV events from massive, continuous long-term monitoring data is a non-trivial task. In this study, a method based on the random decrement technique (RDT) is proposed to identify the VIV response automatically from the massive acceleration response without manual intervention. The raw acceleration data is first processed by RDT and it is found that the RDT-processed data show different characteristics for the VIV response and conventional random response. A threshold based on the coefficient of variation (COV) of peak values of processed data is defined to distinguish between the two kinds of responses. Both random vibration and VIV for a three-DOF (degree-of-freedom) mass-spring-damper system are obtained by numerical simulation to verify the proposed method. The method is finally applied to the Xihoumen suspension bridge for identifying VIV response from three-month monitoring data. It is shown that the proposed method performs comparably with the method of novelty detection. A total of 60 VIV events have been successfully identified. Vortex-induced vibrations for the second to ninth vertical modes with modal frequency within 0.1~0.5 Hz occurs at wind velocity 5–18 m/s, with wind direction nearly perpendicular to bridge axis. Amplitude of VIV generally decreases with increase of wind turbulence intensity; however, noticeable VIV amplitude are still observed for turbulence intensity up to 13% in some cases.

scholarly journals Real-time measurement of radionuclide concentrations and its impact on inverse modeling of <sup>106</sup>Ru release in the fall of 2017

2020 ◽  
Author(s):  
Ondřej Tichý ◽  
Miroslav Hýža ◽  
Václav Šmídl
Keyword(s):  
Real Time ◽  
Temporal Resolution ◽  
Inverse Modeling ◽  
Source Term ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Monitoring Data ◽  
The Real ◽  
Concentration Measurements ◽  
Atmospheric Transport Model

Abstract. Abstract Low concentrations of 106Ru were detected across Europe at the turn of September and October 2017. The origin of 106Ru has still not been confirmed; however, current studies agree that the release occurred probably near Mayak in the southern Urals. The source reconstructions are mostly based on an analysis of concentration measurements coupled with an atmospheric transport model. Since reasonable temporal resolution of concentration measurements is crucial for proper source term reconstruction, the standard one week sampling interval could be limiting. In this paper, we present an investigation of the usability of the newly developed AMARA and CEGAM real-time monitoring systems, which are based on the gamma-ray counting of aerosol filters. These high resolution data were used for inverse modeling of the 106Ru release. We perform backward runs of the Hysplit atmospheric transport model driven with meteorological data from the global forecast system (GFS) and we construct a source-receptor sensitivity (SRS) matrix for each grid cell of our domain. Then, we use our least-squares with adaptive prior covariance (LS-APC) method to estimate possible locations of the release and the source term of the release. On Czech monitoring data, the use of concentration measurements from the standard regime and from the real-time regime is compared and better source reconstruction for the real-time data is demonstrated in the sense of the location of the source and also the temporal resolution of the source. The estimated release location, Mayak, and the total estimated source term, 237 ± 107 TBq, are in agreement with previous studies. Finally, the results based on the Czech monitoring data are validated with the IAEA reported dataset with a much better spatial resolution, and the agreement between the IAEA dataset and our reconstruction is demonstrated.

Backbone Optical Fiber Analysis at 1310 nm and 1550 nm

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Nandhakumar P ◽  
Arun Kumar
Keyword(s):  
Optical Fiber ◽  
Real Time ◽  
Optical Fibers ◽  
Single Mode ◽  
Optical Fiber Communication ◽  
Long Distance ◽  
Fiber Communication ◽  
The Real ◽  
Optical Time Domain Reflectometer ◽  
Optic Communication

AbstractOptical fiber communication is the backbone of the entire telecommunication industries in the world. In this work, the real-time backbone long-distance optical fibers (single mode) are tested and analyzed with two different wavelengths (1,310 nm and 1,550 nm) with the help of optical time domain reflectometer. Using these two different wavelengths, how the losses and events of the backbone optical fibers are changing are compared and analyzed. This work will give a way to study the nature of long-distance backbone optical fiber and understand the real-time application of the fiber optic communication.

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