Temperature-insensitive cable tension monitoring during the construction of a cable-stayed bridge with a custom-developed pulse elasto-magnetic instrument

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1982-1994
Author(s):  
Huan Feng ◽  
Xiucheng Liu ◽  
Bin Wu ◽  
Donghang Wu ◽  
Xiaodong Zhang ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Magnetic Measurements ◽  
Characteristic Curve ◽  
Magnetic Characteristic ◽  
Tension Force ◽  
Magnetic Method ◽  
Cable Tension ◽  
Cable Stayed Bridge ◽  
Feature Parameters ◽  
Magnetic Instrument

Pulse elasto-magnetic method has numerous applications for monitoring cable tension force in cable-stayed bridges. In conventional pulse elasto-magnetic measurements, the feature parameters in frequency domain are seldom discussed. In this study, attempts are made to seek new parameters in frequency domain which are mainly influenced by cable tension force and less sensitive to temperature. A custom-developed pulse elasto-magnetic instrument is employed to conduct cable tension monitoring in the construction stage of a cable-stayed bridge. The field testing results show that only after temperature compensation, the monitoring results of the feature parameters extracted from the magnetic characteristic curve can reflect the stepped changes of cable tension force. Surprisingly, a new frequency-domain parameter, the summation of spectra amplitudes in a carefully selected frequency range, is found to be insensitive to temperature and can well reflect the stepped change behavior of cable tension force. The feasibility of this temperature-insensitive parameter for cable force measurements was verified by field test in two stay cables. The averaged value of the new parameter at each stage linearly depends on cable tension force. The findings about the new frequency-domain parameter may facilitate temperature-insensitive cable tension monitoring in cable-stayed bridge with a pulse elasto-magnetic instrument.

Critical Threshold Value for Monitoring & Management of Cable Tension Force in Cable-Stayed Bridge

2004 ◽  
Vol 270-273 ◽  
pp. 1977-1982
Author(s):  
Hyo Nam Cho ◽  
Young Min Choi ◽  
Sung Chil Lee ◽  
Kyoung Koo Kang ◽  
Man Yong Choi
Keyword(s):  
Threshold Value ◽  
Tension Force ◽  
Critical Threshold ◽  
Cable Tension ◽  
Cable Stayed Bridge

scholarly journals Temperature Effect on Tension Force of Stay Cable of Cable-Stayed Bridge

2019 ◽  
Vol 9 (1) ◽  
pp. 2251-2257
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Ambient Temperature ◽  
Element Model ◽  
Tension Force ◽  
Stay Cable ◽  
Element Analysis ◽  
Cable Tension ◽  
Cable Stayed Bridge ◽  
The Finite Element Model

Cable is the main element of cable-supported bridge, such as suspension bridge, cable stayed bridge and arch bridge. For the cable-stayed bridge, the cable receives the load from the bridge deck and transfer it to the pylon. As the ambient temperature change, the internal force in bridge element including stayed cable will change. This research investigate the ambient temperature effect to the tension force of stayed cable of cable-stayed bridge by comparing the result of finite element model analysis with the field measurement form electromagnetic sensor data. The finite element model of Merah Putih Cable-Stayed Bridge has been developed based on detailed engineering design data. The finite element model is validated using the natural frequency data from dynamic load test of the bridge. The ambient temperature and bridge elements temperature were measured for 24 hours. The finite element analysis were conducted based on field measurement data and the contribution of pylon and girder temperature to the cable tension forces variation was investigated. The output of finite element analysis then compared to the actual cable tension as measured by an electromagnetic sensor. It was found that the ambient temperature will affecting the magnitude of tension force at stay cable and the variation of cable tension has similar pattern of both from the finite element model and electromagnetic data. As the temperature of bridge element increases or decreases, the bridge will experience a deformation. Since the stay cable connected to the pylon at one side and to the girder at the other side, its will make the stay cable elongated or contracted which in turn will affecting the tension force at stay cable. When evaluating the bridge condition based on the tension force at stay cable, the effect of temperature variation need to be considered.

Cable Tension Control of Cable-Stayed Bridge Using Fuzzy Satisfaction Method and Genetic Algorithm

2001 ◽  
Vol 84 (3) ◽  
pp. 39-46
Author(s):  
Hitoshi Furuta ◽  
Masakatsu Kaneyoshi ◽  
Hiroshi Tanaka ◽  
Eiichi Watanabe
Keyword(s):  
Genetic Algorithm ◽  
Tension Control ◽  
Cable Tension ◽  
Cable Stayed Bridge

scholarly journals Spatiotemporal Monitoring and Evaluation Method for Sand-Filling of Immersed Tube Tunnel Foundation

2021 ◽  
Vol 11 (3) ◽  
pp. 1084
Author(s):  
Peng Wu ◽  
Ailan Che
Keyword(s):  
Neural Network ◽  
Elastic Wave ◽  
Frequency Domain ◽  
Bp Neural Network ◽  
Evaluation Method ◽  
Monitoring And Evaluation ◽  
Strong Nonlinearity ◽  
Filling Process ◽  
Time Frequency ◽  
Feature Parameters

The sand-filling method has been widely used in immersed tube tunnel engineering. However, for the problem of monitoring during the sand-filling process, the traditional methods can be inadequate for evaluating the state of sand deposits in real-time. Based on the high efficiency of elastic wave monitoring, and the superiority of the backpropagation (BP) neural network on solving nonlinear problems, a spatiotemporal monitoring and evaluation method is proposed for the filling performance of foundation cushion. Elastic wave data were collected during the sand-filling process, and the waveform, frequency spectrum, and time–frequency features were analysed. The feature parameters of the elastic wave were characterized by the time domain, frequency domain, and time-frequency domain. By analysing the changes of feature parameters with the sand-filling process, the feature parameters exhibited dynamic and strong nonlinearity. The data of elastic wave feature parameters and the corresponding sand-filling state were trained to establish the evaluation model using the BP neural network. The accuracy of the trained network model reached 93%. The side holes and middle holes were classified and analysed, revealing the characteristics of the dynamic expansion of the sand deposit along the diffusion radius. The evaluation results are consistent with the pressure gauge monitoring data, indicating the effectiveness of the evaluation and monitoring model for the spatiotemporal performance of sand deposits. For the sand-filling and grouting engineering, the machine-learning method could offer a better solution for spatiotemporal monitoring and evaluation in a complex environment.

STUDY OF THE TEXTURING IN BSCCO-AG TAPES THROUGH MAGNETIC MEASUREMENTS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3159-3164
Author(s):  
C. FERDEGHINI ◽  
M. R. CIMBERLE ◽  
G. GRASSO ◽  
P. GUASCONI ◽  
A. MALAGOLI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Measurements ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Longitudinal Direction ◽  
Magnetic Method ◽  
Superconducting Compounds

We have developed a method that allows, by a simple set of magnetic measurements, to study the texturing of the grains inside a BSCCO-Ag tape. Because the texture is anisotropic we define the angle ϑ L that identifies the mean grain misalignment angle with respect to the tape surface in longitudinal direction (i.e. rolling direction) and the angle ϑ T in transverse direction. The technique is based on the assumption that, because of the very high anisotropy of the critical current density in BSCCO superconducting compounds, the magnetic moment is essentially generated by the current circulating in the a-b planes of the BSCCO grains. The different magnetisation cycles, measured when the orientation of the magnetic field with respect to the tape surface is changed, depend only on the grain orientation inside the tape, which determines the effective magnetic field component normal to the a-b planes of the grains. Here we present the texture evolution of the BSCCO grains inside silver sheated multifilamentary tape starting from the initial steps of the mechanical deformation up to the final heating stage. The results obtained from the magnetic method are compared with those obtained with other methods, i.e. X-ray diffraction and critical current density anisotropy. Also results obtained on samples prepared in different way will be presented.

Identifying Cable Tension Loss and Deck Damage in a Cable-Stayed Bridge Using a Moving Vehicle

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Shih-Hsun Yin ◽  
Chung-Yu Tang
Keyword(s):  
Computational Study ◽  
Vertical Displacement ◽  
Relative Displacement ◽  
Future Research ◽  
Integration Scheme ◽  
Time Step ◽  
Cable Tension ◽  
Displacement Response ◽  
Cable Stayed Bridge ◽  
Response Vector

This paper presents a computational study on a new method of detecting multiple simultaneous damages in a cable-stayed bridge by use of the analysis of the vertical dynamic response of a vehicle passing the bridge. First, the study uses a finite-element method to simulate the vehicle cable-stayed bridge system. Then, the vertical vibration interaction between the bridge and the vehicle is solved by a time-step integration scheme. In this research, we consider that two kinds of damage including cable tension loss and deck damage may occur simultaneously at different locations. The differences between the vertical displacement responses of a vehicle passing the damaged bridge and the healthy bridge are sampled and called the relative displacement response vector of the vehicle. The proper orthogonal decomposition (POD) is utilized to decompose the relative displacement response vector of the vehicle passing the bridge with unknown multiple damages into an optimal set of basis vectors formed from the ones of the vehicle moving over the known damaged bridges. The associated system parameters variation with the unknown multiple damages can be reconstructed further. Discussions are given concerning the feasibility and limitation of the proposed detection technique as well as directions for future research.

scholarly journals Temperature effect on cable tension forces of cable-stayed bridge

2018 ◽  
Vol 195 ◽  
pp. 012009
Author(s):  
Made Suangga ◽  
Irpan Hidayat ◽  
Juliastuti ◽  
Celine
Keyword(s):  
Temperature Effect ◽  
Cable Tension ◽  
Cable Stayed Bridge

Development of a Low-Cost Automated Tension Estimation System for Cable-Stayed Bridges

2008 ◽  
Author(s):  
Soojin Cho ◽  
Jerome Peter Lynch ◽  
Chung-Bang Yun
Keyword(s):  
Low Cost ◽  
Tension Force ◽  
Modal Parameters ◽  
Wireless Sensing ◽  
Force Estimation ◽  
Cable Tension ◽  
Embedded Algorithms ◽  
Estimation System ◽  
Automated Software ◽  
Cable Stayed Bridges

Cable tension force is one of the most important structural parameters to monitor in cable-stayed bridges. For example, cable tension needs to be monitored during construction and maintenance to ensure the bridge is not overloaded. To economically monitor tension forces, this study proposes the use of an automated wireless tension force estimation system (WFTES) developed solely for cable force estimation. The design of the WFTES system can be divided into two parts: low-cost hardware and automated software. The low-cost hardware consists of an integrated platform containing a wireless sensing unit constructed from commercial off-the-shelf components, a low-cost commercial MEMS accelerometer, and a signal conditioning board for signal amplification and filtering. With respect to the automated software, a vibration-based algorithm using estimated modal parameters and information on the cable sag and bending stiffness is embedded into the wireless sensing unit. Since modal parameters are inputs to the algorithm, additional algorithms are necessary to extract modal features from measured cable accelerations. To validate the proposed WFTES, a scaled-down cable model was constructed in the laboratory using steel rope wire. The wire was exposed to broad-band excitations while the WFTES recorded the cable response and embedded algorithms interrogated the measured acceleration to estimate tension force. The results reveal the embedded algorithms properly identify the lower natural frequencies of the cable and make accurate estimates of cable tension. This paper concludes with a summary of the salient research findings and suggestions for future work.

Frequency-Domain Estimation Method for Vibration-Induced Additional Cable Tension Based on Acceleration Monitoring

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Bin Xu ◽  
Danhui Dan ◽  
Yiming Zhao
Keyword(s):  
Frequency Domain ◽  
Dynamic Stiffness ◽  
Estimation Method ◽  
Dynamic Environment ◽  
Parameter Analysis ◽  
Traffic Load ◽  
Cable Tension ◽  
Measuring Point ◽  
Cable Vibration ◽  
Acceleration Data

Abstract Under excitation due to the environment or traffic load, cable vibration never ceases; thus, fatigue cycles generated by vibration-induced additional cable tension (VACT) owing to the change of the cable configuration from static to dynamic are significantly frequent. Therefore, VACT is a non-negligible cable-fatigue load. To investigate the cable dynamic stability and fatigue, it is necessary to determine VACT in a dynamic environment. Herein, a method for estimating VACT in the frequency-domain by using acceleration data is proposed. In this method, according to the cable vibration control equation, the frequency-domain relationship between the VACT and the vibration response of the measuring point is established based on the dynamic stiffness. Parameter analysis simplifies the proposed model to estimate VACT using only acceleration data. The proposed method is verified with cable acceleration data.

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