scholarly journals Research on Non-Contact and Non-Fixed Cable Force Measurement Based on Smartphone

2021 ◽  
Vol 11 (19) ◽  
pp. 8902
Author(s):  
Yongwei Wang ◽  
Kunyao Li ◽  
Yuan Chen ◽  
Shuyuan Xu ◽  
Wenchi Shou
Keyword(s):  
Force Measurement ◽  
Real Life ◽  
Operation Time ◽  
Maximum Error ◽  
Video Data ◽  
Stay Cable ◽  
Vibration Displacement ◽  
Cable Force ◽  
Cable Force Measurement ◽  
Cable Forces

Stay cable is the major load-carrying element in cable-stayed bridges. The process of monitoring cable forces would be beneficial to ensure the safety of bridges. The conventional sensor-based approaches to measure stay cable forces is complicated in operation, time-consuming and relatively expensive. In order to confront these disadvantages, a lightweight measurement method using smartphone imagery was proposed in this paper. The video data acquisition process was first standardized by using a pre-designed target. Then, a novel algorithm to extract the vibration displacement of stay cables under complex condition was developed. An automatic correction algorithm was provided to further improve the displacement results. On top of that, a smartphone-based software for determining cable forces was developed and tested on a real-life bridge. The results showed a maximum error of 1.99% compared with the cable force obtained by using a dynamic tester. The developed software is proven to be feasible in real-life projects and can achieve high accuracy in cable force determination. At the same time, the proposed method does not require a fixed camera for measurement and is not limited by personnel experience and measurement time, facilitating real-time monitoring of multiple projects, multiple cable surfaces and multiple personnel in a visual vibration environment.

Portable and convenient cable force measurement using smartphone

2015 ◽  
Vol 5 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Xuefeng Zhao ◽  
Ruicong Han ◽  
Yanbing Ding ◽  
Yan Yu ◽  
Quanhua Guan ◽  
...  
Keyword(s):  
Force Measurement ◽  
Cable Force ◽  
Cable Force Measurement

Feasibility Study for Vision-Based Cable Force Measurement Using Smartphone

2016 ◽  
Author(s):  
Xuefeng Zhao ◽  
Kwang Ri ◽  
Yan Yu ◽  
Chunil Kang ◽  
Mingchu Li ◽  
...  
Keyword(s):  
Measurement Method ◽  
Force Measurement ◽  
Smartphone Application ◽  
Cable Model ◽  
Construction Period ◽  
Service Period ◽  
Cable Force ◽  
Vibration Responses ◽  
Cable Force Measurement ◽  
Circular Target

An accurate cable force measurement is one of very important practical problems during construction period as well as during service period of cable stayed bridge. In the recent years, with the advances in smartphone technologies, it is possible to rapidly evaluate structural health status and postevent damage using ubiquitous smartphones. In this paper, a novel vision-based cable force measurement method using smartphone camera is proposed for the first time, which enable to estimate cable force by recognizing cable vibration using smartphone camera, and then cable model test is carried out to verify the feasibility of the proposed method. The comparison test between the smartphone application Orion-CC measuring cable force from smartphone built-in accelerometer and the proposed method is conducted on a laboratory scale cable model with different sampling rates. In the proposed method, the vibration responses of cable are obtained by monitoring displacements of a preprinted black circular target attached on the cable model using smartphone camera. The test results showed satisfactory agreements between two methods in both frequency domain and cable force value, demonstrating the feasibility of the proposed cable force measurement method and its advantages such as convenience, ease of operation, and speediness.

The Research on Cable Force Measurement Based on Degenerated Element with Frequency Method

2013 ◽  
Vol 405-408 ◽  
pp. 1709-1715
Author(s):  
Xin Cui ◽  
Yong Jiang ◽  
Li Wen Fu ◽  
Jin Feng Wang
Keyword(s):  
Numerical Method ◽  
Theoretical Basis ◽  
Force Measurement ◽  
Beam Element ◽  
Testing System ◽  
Frequency Method ◽  
Operation Procedure ◽  
Cable Force ◽  
Cable Force Measurement ◽  
The Given

At present, among the methods of cable force measurement, the frequency method is applied extensively for its mature theory and rapid and repeated operation procedure. Based on the theory of frequency method measurement, it generally uses the numerical method with beam element to analysis the parameters of cables under the given conditions. However, the conventional beam element is not able to simulate the bending stiffness in beams section. Therefore, it turns to degenerated beam element to simulate cables and the results agree well with the results based on beam element and formulas calculation, and it provides theoretical basis for the later cable force testing system.

Smartphone-Based Mobile Testing Technique for Quick Bridge Cable–Force Measurement

2017 ◽  
Vol 22 (4) ◽  
pp. 06016012 ◽  
Author(s):  
Xuefeng Zhao ◽  
Ruicong Han ◽  
Yan Yu ◽  
Weitong Hu ◽  
Dong Jiao ◽  
...  
Keyword(s):  
Force Measurement ◽  
Testing Technique ◽  
Mobile Testing ◽  
Cable Force ◽  
Bridge Cable ◽  
Cable Force Measurement

Impact Analysis of the Flexural Rigidity on the Frequency and Tension of the Stay Cable

2013 ◽  
Vol 540 ◽  
pp. 153-163
Author(s):  
Yong Ming Sun ◽  
Hang Sun
Keyword(s):  
Finite Element ◽  
Impact Analysis ◽  
Flexural Rigidity ◽  
Force Measurement ◽  
Element Model ◽  
Stay Cable ◽  
Frequency Method ◽  
Actual Measurement ◽  
Cable Force ◽  
Balance Curve

Research and practice show that frequency method is still the most practical and accurate method among all kinds of cable force measurements. Based on the classical string vibration theory, the finite element model of stay cable was created, and a method of iteratively computing stay cable balance curve considering with flexural rigidity was proposed. How dose the flexural rigidity affects the balance curve of stay cable was discussed, and the changing curves of the distance-to-sagging ratio following the pull-to-bend ratio were plotted, which indicated the bigger flexural rigidity, the smaller sagging. 25 pairs cable modality of Xichang cable stayed bridge were accurately analyzed, mode crossover was testified by finite element method, changing curves of frequency and mode shape following the cable force were separately plotted, and changing rule was induced, practical cable force computing method was given. Frequency difference is suitable to judge the rank of actual measurement frequency, and the second frequency is recommended to compute cable force. Engineering instance analysis testified, the method of practical cable force measurement could rule out errors by mode crossover, and be applied to cable with any lengths and any force.

scholarly journals Evaluation of Cable Force Changes Effects on Cable Stayed Bridge

2020 ◽  
Vol 6 (11) ◽  
pp. 2159-2174
Author(s):  
Theint Theint Thu Soe ◽  
San Yu Khaing
Keyword(s):  
Finite Element ◽  
Force Measurement ◽  
Research Work ◽  
Tension Stress ◽  
Percentage Increase ◽  
Stay Cable ◽  
The Real ◽  
Finite Element Software ◽  
Cable Stayed Bridge ◽  
Cable Force

The proposed bridge, which is cable stayed bridge crosses the Hlaing River that flows through Western Yangon. It was completed in 2000 and is currently used to connect Insein Township with Hlaing Tharyar Township. It has the 20 years’ service life. It requires the inspection and the evaluation of the real condition of the structure. As cable element plays an important role in cable structures, evaluation of the real state of the stay cable is one of the main focuses of the cable stayed bridge. Firstly, in the research work all cables are inspected to evaluate the current condition of the cables with included visual inspection and vibration-based cable force measurement method. With the help of static and moving load analysis, the effect of force change cables in which the successive force changes are considered, and the possible cable loss effect on the structural behavior of the bridge are also investigated. The finite element model of the cable stayed bridge is developed based on the geometric shape and material properties from MOC and is modelled with finite element software MIDAS Civil. The tension forces obtained by inspection over years (2000 to 2018) using vibration-based measurements method are compared with the measured intact cable forces. According to the results of the data analysis, it is observed that the cables force variations of the seven cables are abnormal conditions. In order to evaluate the condition of a bridge effected by cable force variation, the two parameters are considered; percentage increase in tension stress of all cables and percentage increase in deflection of the deck. The present study describes the structural response of the bridge in order to evaluate the actual safety of the bridge with abnormal force change cables, and also examines the consequences of one cable failure. Doi: 10.28991/cej-2020-03091609 Full Text: PDF

scholarly journals Suspender Replacement Method for Long-Span Concrete-Filled Steel Tubular Arch Bridges and Cable Force Measurement Based on Frequency Method

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Yulin Deng ◽  
Luming Deng
Keyword(s):  
Force Measurement ◽  
Estimation Method ◽  
Traffic Load ◽  
Frequency Method ◽  
Arch Bridge ◽  
Calculated Length ◽  
Long Span ◽  
Replacement Method ◽  
Cable Force ◽  
Cable Force Measurement

The suspenders on the sides of an arch bridge are highly vulnerable to damage caused by traffic load and environmental corrosion. To accurately estimate the cable force of suspenders, herein, we analyse the influencing factors through a suspender tension test based on the principle of suspender vibration. The frequency of each suspender of the bridge is evaluated using the frequency method. By combining the cable force data measured directly and the measured suspender frequency, the formulas for calculating the cable forces of long and short suspenders are fitted, and a reasonable estimation method for the calculated length of short suspenders is provided. The formulas are verified through application to a CFST arch bridge. Results indicate that the proposed formula effectively considers the influence of the sleeve on the overall calculated length of the suspender. The formula calculates the suspender cable force with higher accuracy, proving its suitability for engineering use.

Cable Force Measurement Technology and Engineering Application

2021 ◽  
Vol 62 (3) ◽  
pp. 185-194
Author(s):  
Ju-wei Xia ◽  
Yun-long Yao ◽  
Xiao-shun Wu ◽  
Yuan-hong Chen
Keyword(s):  
Real Time ◽  
Structural Engineering ◽  
Force Measurement ◽  
Engineering Application ◽  
Force Balance ◽  
Measurement Technology ◽  
Practical Engineering ◽  
Cable Force ◽  
Force Monitoring ◽  
Cable Force Measurement

With the continuous development of prestressing technology, cables have been widely used in structural engineering. A special concern in practical engineering is selecting the appropriate cable force measurement technology. This paper analyzes and introduces the principle of cable force measurement technology commonly used in current engineering from three aspects, namely, strain, vibration and wave fluctuation, and force balance. Combined with an actual project, the selection and arrangement of measuring points in the cable pre-tension measurement and other issues are discussed. The engineering example shows that the cable force measurement method based on FBG sensor presented in this paper can capture the action of each construction tensioning operations in real time and accurately. Monitoring the tension of the structure in real time is convenient for engineers and technician. The process is suitable for cable force monitoring during the construction tensioning stage. Furthermore, the EM sensor has good stability and durability and is suitable for long-term cable force monitoring.

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