Accurate and efficient identification of cable natural frequencies for cable tension monitoring by vibration frequency method

2011 ◽  
Author(s):  
Lin Liu ◽  
Weimin Chen ◽  
Peng Zhang ◽  
Shunren Hu ◽  
Wei Luo
Keyword(s):  
Vibration Frequency ◽  
Natural Frequencies ◽  
Frequency Method ◽  
Cable Tension

Design and Experimental Investigations of a Vibration Based Wireless Measurement System for Bridge Cable Tension Monitoring

2014 ◽  
Vol 17 (11) ◽  
pp. 1657-1668 ◽  
Author(s):  
Yan Yu ◽  
Chunwei Zhang ◽  
Xinqun Zhu ◽  
Won Hee Kang ◽  
Xingquan Mao ◽  
...  
Keyword(s):  
Monitoring System ◽  
Measurement System ◽  
Vibration Frequency ◽  
Identification Algorithm ◽  
Frequency Method ◽  
Cable Tension ◽  
Wireless Monitoring ◽  
Cable Stayed Bridge ◽  
Wireless Measurement ◽  
Bridge Cable

Cables are important components of a cable-stayed bridge, and the cable tension is a crucial factor in determining the overall condition assessment of a cable-stayed bridge structure. Based on the vibration frequency method, a wireless monitoring system for bridge cable tension force monitoring has been investigated and experimentally validated through laboratory and field tests in this paper. The vibration frequency-based method for cable tension measurement, the design method of the wireless measurement system with embedded identification algorithm, the test procedures, and relevant results are discussed, respectively. The developed wireless monitoring system is verified by a bridge model test in the laboratory and full-scale bridge tests in the field. Field experimental results show that the relative error between this wireless monitoring system and the reference wired system values is within 0.5%. Therefore, the developed wireless measurement system can provide an estimation of cable tension with sufficient accuracy. Moreover, the developed system is highly integrated and convenient in terms of installation and dismantling, and it has potential applicability prospects in emergency for the quick detection of cable tension.

Field Measurement of Cable Tension Using Energy Method

2011 ◽  
Vol 230-232 ◽  
pp. 708-712
Author(s):  
Qi Lin Zhang ◽  
Da Lin Li ◽  
Ru Jin Ma
Keyword(s):  
Vibration Frequency ◽  
Energy Method ◽  
Vibration Mode ◽  
Tensile Force ◽  
Frequency Method ◽  
Cable Tension ◽  
Cable Structures ◽  
Simple Boundary ◽  
The Common ◽  
Energy Conservation Principle

For existing cable structures, vibration frequency method (VFM) seems to be the common way to determine the tensile force of the cables. However, the applicability of this method is limited by the specific conditions of cables. Only well tensioned slender cables with simple boundary conditions can be measured through VFM directly without causing much error. In this paper, the vibration mode of the cable is measured and then cable tension is calculated via energy conservation principle.

Cable Tension Measurement of Cable Stayed Bridge Based on Frequency Method

2013 ◽  
Vol 405-408 ◽  
pp. 1587-1592
Author(s):  
Zhi Hua Sun ◽  
Ping Yang
Keyword(s):  
Vibration Frequency ◽  
Indirect Method ◽  
Flexural Rigidity ◽  
Engineering Practice ◽  
Frequency Method ◽  
Cable Tension ◽  
String Vibration ◽  
Vibration Theory ◽  
Cable Stayed Bridge ◽  
Measured Frequency

The frequency method is an indirect method of measuring cable tension, in which using the relation between vibration frequency and cable tension, and measured frequency. It has been found wide use because of its simplicity, practicable use, higher accuracy and the instrument is easy to carry. The principle of the frequency method is based on the vibration theory of string or beam. The flexural rigidity of cable is ignored in string vibration theory, but included in beam vibration theory; therefore the latter is more approaching the engineering practice.

scholarly journals Design of Vibration Frequency Method with Fine-Tuned Factor for Fault Detection of Three Phase Induction Motor

2021 ◽  
Vol 3 (1) ◽  
pp. 52-65
Author(s):  
Thomas Amanuel ◽  
Amanuel Ghirmay ◽  
Huruy Ghebremeskel ◽  
Robel Ghebrehiwet ◽  
Weldekidan Bahlibi
Keyword(s):  
Induction Motor ◽  
Vibration Frequency ◽  
Vibration Monitoring ◽  
Slight Variation ◽  
Frequency Method ◽  
Monitoring Method ◽  
Stator Current ◽  
Research Article ◽  
Proposed Model ◽  
Fault Parameters

This research article focuses on industrial applications to demonstrate the characterization of current and vibration analysis to diagnose the induction motor drive problems. Generally, the induction motor faults are detected by monitoring the current and proposed fine-tuned vibration frequency method. The stator short circuit fault, broken rotor bar fault, air gap eccentricity, and bearing fault are the common faults that occur in an induction motor. The detection process of the proposed method is based on sidebands around the supply frequency in the stator current signal and vibration. Moreover, it is very challenging to diagnose the problem that occur due to the complex electromagnetic and mechanical characteristics of an induction motor with vibration measures. The design of an accurate model to measure vibration and stator current is analyzed in this research article. The proposed method is showing how efficiently the root cause of the problem can be diagnosed by using the combination of current and vibration monitoring method. The proposed model is developed for induction motor and its circuit environment in MATLAB is verified to perform an accurate detection and diagnosis of motor fault parameters. All stator faults are turned to turn fault; further, the rotor-broken bar and eccentricity are structured in each test. The output response (torque and stator current) is simulated by using a modified winding procedure (MWP) approach by tuning the winding geometrical parameter. The proposed model in MATLAB Simulink environment is highly symmetrical, which can easily detect the signal component in fault frequencies that occur due to a slight variation and improper motor installation. Finally, this research article compares the other existing methods with proposed method.

Experimental Modal Analysis of Fan Vibration Frequency

2011 ◽  
Vol 138-139 ◽  
pp. 395-398
Author(s):  
Li Jun Wang ◽  
Zhi Yang Pan
Keyword(s):  
Modal Analysis ◽  
Vibration Frequency ◽  
Natural Frequencies ◽  
Experimental Modal Analysis ◽  
Resonance Vibration ◽  
Pneumatic Conveying ◽  
Combine Harvester

Fan is used for pneumatic conveying grain in the 4ZTL-1800 combine harvester threshing prior to cutting. In order to decrease power consume of it, the experimental modal analysis of fan was done by using hammer-hitting pulse-inspirit method. The natural frequencies of fan vibration is obtained, which is contrasted with inspirit frequency of fan, then resonance vibration of fan is found and its frequency is at 125Hz, which verifies the result of the experimental modal analysis.The results are beneficial to decrease power consume of fan.

Tension Measurement of Suspenders on Yulong Bridge with Frequency Method

2013 ◽  
Vol 303-306 ◽  
pp. 642-645
Author(s):  
Wei Ming Zhu ◽  
Yi Tang Zhou ◽  
He Xian Su ◽  
Zheng Cong Lai
Keyword(s):  
Natural Frequencies ◽  
Suspension Bridge ◽  
Theoretical Background ◽  
Frequency Method ◽  
Subsequent Calculation

This paper describes the tension measurement performed on the suspenders on a self-anchored suspension bridge, Yulong Bridge, on the basis of measuring the natural frequencies of the suspenders in a free-damped vibration and subsequent calculation of the forces using simplified vibrating chord theory. The theoretical background and the practical and economic advantages of this method are discussed, as well as its most relevant limitations.

Effects of Fixed Versus Variable Reference Frequencies on Psychophysical Judgments of Vibration

1978 ◽  
Vol 20 (1) ◽  
pp. 97-102 ◽  
Author(s):  
B.K.N. Rao ◽  
B. Jones
Keyword(s):  
Vibration Frequency ◽  
Reference Stimulus ◽  
Reference Frequency ◽  
Matching Method ◽  
Variable Stimulus ◽  
Frequency Method ◽  
Fixed Reference ◽  
Frequency Magnitude

Equal magnitude contours for vibration were obtained by two methods from ten seated subjects exposed to sinusoidal vibrations in three axes. In the traditional “fixed reference frequency” method, subjects were asked to adjust the amplitude of vibration in order to match for equal vibratory magnitude of a variable stimulus (of from 1 to 30 Hz) to a fixed reference vibration stimulus. The reference stimulus corresponded to the ISO 1–4 min “reduced comfort boundary” level; i.e., 6 Hz at 0.9 m/s2 (rms acceleration) for vertical (±gz) axis and 1 Hz at 0.62 m/s2 rms acceleration for the lateral (±gy) and longitudinal (±gx) axes. In the modified “progressive matching” method, subjects were exposed initially to the same reference stimulus and matched the adjoining stimulus vibratory frequency magnitude to it. Then, however, the newly matched vibration frequency was used as the next reference stimulus, the subjects matched the adjoining frequency magnitude to this “new” reference stimulus, etc. over the same range of frequencies (from 1 to 30 Hz). The advantages and shortcomings of the two methods are discussed.

Research on Monitoring and Control for Suspender Cable Tension of Half-Through Concrete Filled Steel Tube Arch Bridge

2013 ◽  
Vol 859 ◽  
pp. 131-134
Author(s):  
Fu Li Zhao ◽  
Yi Qiang Xiang ◽  
Qiang Qiang Wu
Keyword(s):  
Steel Tube ◽  
Calculation Formula ◽  
Test Results ◽  
Monitoring And Control ◽  
Frequency Method ◽  
Cable Tension ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Cable Force ◽  
Force Calculation

The measurement accuracy of the cable tensions in the hanger rods of concrete filled steel tube arch bridges is important for the correct evaluation of bridges condition. Based on Jinpan Bridge-a half through concrete filled steel tube arch bridge with 80 m span in Tiantai, it was put forward the vibration frequency method for testing and evaluate suspender tensions with the help of analysis vibration characters of the suspender. The precision of cable force calculation formula was verified after comparing the practical tension with the designed tension obtained from tension jack method. Then, according to the test results and values predicted by the presented cable force calculation formula, the cable tensions were adjusted. Cable tension test results in the finished bridge show that this method is feasible.

scholarly journals Vibration frequency of prestress slender beams resting on Winkler elastic foundation

2006 ◽  
Vol 28 (4) ◽  
pp. 241-251
Author(s):  
Nguyen Dinh Kien
Keyword(s):  
Axial Force ◽  
Vibration Frequency ◽  
Strain Energy ◽  
Natural Frequencies ◽  
Winkler Foundation ◽  
The Finite Element Method ◽  
Various Boundary Conditions ◽  
Winkler Elastic Foundation ◽  
Mass Matrices ◽  
Slender Beams

The present paper investigates the vibration frequency of slender beams prestressing by axial force and resting on an elastic Winkler foundation by the finite element method. A beam element taking the effects of both the prestress and foundation support into account is formulated using the expression of strain energy. Using the developed element, the natural frequencies of beams having various boundary conditions are computed for different values of the axial force and foundation stiffness. The influence of the axial force and the foundation stiffness on the frequency of the beams is investigated. The effect of partial support by the foundation and the type of mass matrices on the vibration frequency of the beam is also studied and highlighted.

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