CN203396752U - Magnetizer probe detection system for nondestructive bridge sling anchor cable body guided wave testing - Google Patents
Magnetizer probe detection system for nondestructive bridge sling anchor cable body guided wave testing Download PDFInfo
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- CN203396752U CN203396752U CN201320273524.9U CN201320273524U CN203396752U CN 203396752 U CN203396752 U CN 203396752U CN 201320273524 U CN201320273524 U CN 201320273524U CN 203396752 U CN203396752 U CN 203396752U
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Abstract
The utility model discloses a magnetizer probe detection system for nondestructive bridge sling anchor cable body guided wave testing. The system comprises an exciting magnetizer, a receiving magnetizer and a detection system host, wherein the exciting magnetizer and the receiving magnetizer are used for transmitting and receiving one-point exciting torsion or longitudinal mode guided waves; the exciting magnetizer and the receiving magnetizer are respectively sleeved on a cable close to an anchor end at an interval, and are respectively connected with the detection system host through data wires; the detection system host is an electromagnetic waveguide detection device. The magnetizer probe detection system can be used for solving the technical problem of being capable of effectively, conveniently and accurately detecting the cables in cable-stayed bridges and suspension bridges.
Description
Technical field
The utility model relates to a kind of bridge security pick-up unit, particularly the safe handling pick-up unit to cable-stayed bridge, suspension bridge.
Background technology
Cable-stayed bridge, suspension bridge are because its cost is low, and construction speed is fast, in the bridge construction of large span, obtain develop rapidly.Built main span has hundreds of seat at the more than 200 meters bridges that cable is main load bearing component of take in the world, wherein across footpath, is greater than total nearly hundred of the cable-stayed bridge of 400 meters or suspension bridge.China builds various types of cable-stayed bridges or suspension bridge so far nearly 200, wherein has tens Zuo Kua footpaths to be greater than 200 meters, has become and has had the country that cable bridge is maximum.
Cable is as the main load bearing component of this class bridge, and its health status is significant to guaranteeing the health and safety of bridge.And the anchor head cable body of cable is the most severe position of stressing conditions in whole stayed structure, growth along with bridge active time, because micro-vibrations such as wind shakes, raindrop cause that the vibration of cable is sent to cable end anchor part, make the safety problem in anchor head cable body territory more serious and outstanding.All occurred both at home and abroad the burn into that takes the lead in due to anchor head cable body break the cable causing come off, rupture so that cause change rope, the major accidents such as bridge of collapsing, lose huge.
The reason of above-mentioned disconnected rope accident and drag-line too early decline in serviceable life is, because drag-line is for a long time in outdoor service state, directly be subject to sunshine, influence of temperature change and erosion by wind and rain effect, cause its guard system ageing failure, cause that drag-line protects PE cover cracking outward, aqueous vapor enters in the high-tensile steel wires of drag-line, comes together in the anchor head region of drag-line along steel wire; While work due to drag-line simultaneously pulling force generally at tens tons to hundreds of ton, through foreign scholar, study and show, drag-line is under high-stress state, corrosion speed is even faster by the twice reaching under unstress state.In addition, the random vibration that wind, rain, carload excitation are descended to produce can cause mutual wearing and tearing, the fatigue of drag-line steel wire and the damage of lasso protection layer between steel wire, and these all can affect the serviceable life of drag-line, bury serious hidden danger to the safe handling of bridge.
For the problems referred to above, brainstrust carries out Suo Li detection with divided oscillation signal analysis system pair four drag-lines parallel with the drag-line shaking; With instrument, detect drag-line self vibration frequency under wind effect, and with this vibration frequency inverse, go out the Suo Li of drag-line, then the Suo Litong measuring was compared in the past, could judge whether drag-line has problems.Yet if guy anchor fixed end exists local fracture of wire or corrosion damage, the Suo Li of drag-line changes very little, therefore cannot only judge the health status of drag-line by Suo Li.Due to drag-line coated outside matcoveredn, therefore whether the steel wire of the inside ruptures or the effective detection method of the temporary transient shortage of corrosion simultaneously.
The research detecting at anchor head cable body both at home and abroad is at present considerably less, mainly contain supersonic testing method, during detection, must directly contact at drag-line anchor slab place parallel steel wire or prestress wire and realize detection, yet because drag-line anchor slab general using epoxy resin and iron sand are shut, do not have space to realize and detect, in the practical application of drag-line, do not have space utilization the method to detect simultaneously.
To sum up, finding a kind of anchor head cable body method that detects comprehensively, at a distance, online cable in cable-stayed bridge, suspension bridge, is the powerful guarantee that effectively solves the safe handling of bridge.
Summary of the invention
The purpose of this utility model is to provide the inspection of a kind of probe of the magnetizing apparatus for the Non-Destructive Testing of bridge sling anchor head cable body guided wave
Examining system, to solve the technical matters to cable carries out effective, convenient and accurate detection in cable-stayed bridge, suspension bridge.
The utility model is realized foregoing invention object, and the technical scheme adopting is as follows:
A magnetizing apparatus probe detection system for bridge sling anchor head cable body guided wave Non-Destructive Testing, comprises transmitting and receives the excitation magnetizing apparatus of single-point-excitation torsion or longitudinal mode guided wave and receive magnetizing apparatus, detection system main frame; Described excitation magnetizing apparatus is nested with on the close cable of anchor head end at interval respectively with receiving magnetizing apparatus, and by data line, is connected with detection system main frame respectively, and described detection system main frame is an electromagnetic waveguide pick-up unit.
Described detection system main frame comprise the data acquisition unit being connected with reception magnetizing apparatus with filtering and amplifying circuit by prime amplifier, the pocket computer of connection data collecting unit, the signal generating unit being connected with pocket computer, the gating circuit being connected respectively with pocket computer with signal generating unit, with the power amplifier that gating circuit is connected respectively with signal generating unit, described excitation magnetizing apparatus is connected with power amplifier.
The utility model has the advantages that and utilize Dispersion and the multi-mode characteristic of guided wave in different materials, realize stay cable end anchor head cable body defects detection, and by drag-line being made regular check on to the working condition that obtains in-service cable, instruct cable maintenance work, extend cable serviceable life, reduce disconnected rope probability, guarantee the safe operation of bridge.Thus, can avoid on the one hand, owing to drawing the serious accidents such as the fracture of Hanger Anchor head region causes that bridge decays, the more important thing is and utilizing detection data can avoid blindly changing the waste of drawing suspension rod and causing.
Accompanying drawing explanation
Fig. 1 is the structural representation of tested anchor head of the present utility model.
Fig. 2 is magnetizing apparatus scheme of installation of the present utility model.
Fig. 3 is circuit structure composition frame chart of the present utility model.
Fig. 4 is the signal acquisition process schematic diagram that magnetic striction wave guide of the present utility model detects.
Embodiment
The structure of detected anchor head 10 of the present utility model, referring to Fig. 1, comprising: anchor cup 1, nut 2, bearing 3, high tensile steel wire 4, HDPE sheath 5, extending 6, heat-shrinkable T bush 7, anchor slab 8.Figure 2 illustrates excitation magnetizing apparatus 11 and receive magnetizing apparatus 12, the installation site schematic diagram on cable 9 during detection.
A magnetizing apparatus probe detection system for bridge sling anchor head cable body guided wave Non-Destructive Testing, its electric circuit constitute, referring to Fig. 3, comprises transmitting and receives the excitation magnetizing apparatus 11 of single-point-excitation torsion or longitudinal mode guided wave and receive magnetizing apparatus 12 and detection system main frame; Described excitation magnetizing apparatus is nested with on the close cable 9 of anchor head end at interval respectively with receiving magnetizing apparatus, and by data line 13,14, is connected with detection system main frame 15 respectively, and described detection system main frame is an electromagnetic waveguide pick-up unit.
Described detection system main frame comprise the data acquisition unit being connected with reception magnetizing apparatus with filtering and amplifying circuit by prime amplifier, the pocket computer of connection data collecting unit, the signal generating unit being connected with pocket computer, the gating circuit being connected respectively with pocket computer with signal generating unit, with the power amplifier that gating circuit is connected respectively with signal generating unit, described excitation magnetizing apparatus is connected with power amplifier.
Parameter setting of the present utility model comprises that the setting of layer structure parameter, the setting of endothecium structure parameter, calculating parameter setting and display parameter arrange etc.
(1) layer structure parameter arranges
Need to input outer field external radius, inside radius, Poisson ratio, the velocity of sound and density of material according to the size of layer structure, wherein the velocity of sound is the speed that ultrasound wave is propagated in material.
(2) endothecium structure parameter arranges
Need to input outer field inside radius, Poisson ratio, the velocity of sound and density of material according to the size of layer structure, wherein the velocity of sound is the speed that ultrasound wave is propagated in material.
(3) calculating parameter setting
" minimum frequency " and " maximum frequency " is the frequency range of calculating, and initial setting up frequency range is 0-600kHz." frequency step " is the step-length of calculating, and is initially set to 10kHz." maximal rate " is the parameter that the image longitudinal axis is set, the maximal value of the representative image longitudinal axis, and the image longitudinal axis scope of initial setting up is 8000m/s.Velocity error and cutoff frequency error all arrange counting accuracy, and error is less, and precision is higher, are initially set to 0.01m/s and 0.1Hz.
(4) display parameter setting
" phase velocity scope " and " group velocity scope " is that the longitudinal axis parameter area that shows result is set, and initial setting up velocity range is 0-8000m/s." whether show phase velocity curve " and " whether showing group velocity curve " is to arrange whether to show curve.Whether whether " calculate L (0, m) mode ", " calculate T (0, m) mode ", " whether calculating F (n, m) mode " are to arrange whether to calculate 3 kinds of different mode, the exponent number that " n " is mode of flexural vibration.
From detection signal, extract the method for dispersion curve, pumping signal is that the pulse signal that windowing obtains to cosine signal obtains after power amplifier amplifies, characteristic by signal windowing can know, the actual signal obtaining is for take the complicated ingredient signal that excitation frequency is main frequency.The frequency of actual pumping signal is mainly distributed in the scope of [df+f, df+f], and wherein f is excitation frequency.The energy of the guided wave of excitation magnetizing apparatus excitation depends on the intensity of stimulating frequency and excitation signal, and stimulating frequency is the closer to the natural vibration frequency of member, and the intensity of excitation signal is more done, and the energy of guided wave is higher.The natural vibration frequency of member all concentrates on the frequency range that frequency ratio is lower conventionally, therefore when excitation frequency is f, the frequency range of the guided wave signals of acquisition is [0, f+df], and the guided wave signals intensity of low-frequency range is better than other frequency ranges.The intensity that receives the signal that magnetizing apparatus receives is relevant in the intensity of guided wave signals, and guided wave signals intensity is larger, and signal is stronger, thus the frequency distribution that receives signal at [0, f+df], and the signal intensity of low-frequency range is relatively strong.
In actual guided wave detects, the distance of excitation magnetizing apparatus and reception magnetizing apparatus very closely even overlaps, and makes the dispersion phenomenon of first signal not obvious, therefore do not get first signal for obtaining dispersion curve.Guided wave is propagated in member and transmitting can bring decay and mode-conversion.Consider, second signal getting only process primary event obtains dispersion curve.
One section of wider frequency band of the general covering of magnetic striction wave guide detection signal, simultaneously owing to having frequency dispersion, phenomenon and the various noise such as multi-modal, cause being difficult to directly by detection signal, obtain defect information, so need to detection signal be treated to waveform intuitively by suitable signal processing method, be easy to distinguish defect.According to the needs of signal processing method real-time, can be divided into real-time signal-processing method and follow-up signal disposal route.According to the result of flaw indication signature analysis, select the bandpass filter of being built by hardware circuit as real-time signal-processing method and by the bandpass filter of software programming as follow-up signal disposal route.
The major function that detects software has signal generating unit control, door control unit control, data acquisition, data analysis, data processing, data compression etc.According to the feature of software platform architecture, software is divided into gathering and controls and two modules of data analysis processing.
Acquisition control module comprises the control of the collection, signal generating unit and the door control unit that detect data.
Data acquisition realizes by collecting unit, and the content that need to arrange at software platform comprises:
(1) analog channel is selected
The selection of analog channel is generally determined in conjunction with the analog input channel sum of collecting unit and the number of sensor, considers the needs that magnetic striction wave guide detects, and generally selects 1 to 2 passage.
(2) sample frequency is selected
Sample frequency must, in collecting unit usable range, need to be considered the highest effective frequency f in signal
max, based on sampling law, require sample frequency to be greater than 2*f
max, as undistorted in order to guarantee signal, require sample frequency to be greater than 10*f
max.The selection of frequency generally has two kinds of forms, and region is selected and discrete selection.It is all numerical value that are received within the scope of that region is selected; Discrete selection is only to receive one group of fixing numerical value.Because the excitation frequency of detection system is generally a plurality of discrete values, so software only provides the discrete sampling matching frequency.
(3) sampling measurement range selection
Sampling range need to be considered the effective amplitude of maximum of signal, too littlely cannot obtain complete signal message, and too conference reduces the minimum discernable precision of signal, consider and set sampling range.
(4) sampling precision is selected
Sampling precision is the figure place of A/D, can determine according to the effective amplitude of the minimum of signal, crosses conference and increases considerably data volume, and valid data are lost in too small meeting.
(5) sampling time is selected
Sampling time is each lasting time of sampling, need to determine according to the distance of the distance of elastic wave actual propagation and detection.
(6) sampling number is selected
Repeatedly the object of sampling is in order to utilize digital averaging algorithm noise reduction, and when multiplicity N → ∞, for zero mean noise, its mathematical expectation is zero, and the Signal-to-Noise of average rear output is infinitely great.When N has in limited time, for white noise, cumulative mean can make signal to noise ratio (S/N ratio) improve
doubly.For coloured noise, noise is improved ratio will be lower than the situation of white noise.Rule of thumb sampling number is generally between 300 to 500.
(7) triggering mode is selected
Triggering mode mainly contains that software triggers and two kinds of external trigger.It is generally acknowledged that external trigger function is to be realized data acquisition unit is started and stop the control gathering by outside trigger pulse.In addition, the mode that also can inquire about by software in data acquisition unit triggers control according to the input signal of numeral mouth or simulation mouth.
The control of signal generating unit and door control unit is used for controlling the specific output of pulse signal of generation to power amplifier, and needing setting value is excitation frequency, amplitude, periodicity, transmission interval, and provides trigger pip to start sampling to collecting unit.
The signal acquisition process that magnetic striction wave guide detects is referring to Fig. 4: initialization collecting unit first, and each parameter of successful post-equalization is confirmed the duty of each equipment, parameter is log-on data capture program correctly, opens flow process and controls thread; In thread, first read mouthful state that triggers, if the trigger pip of receiving, starts single acquisition, when judging total times of collection after single acquisition, reach setting value, as do not reached, again enter circulation until reach the times of collection of setting, the whole sampling routine of the ED of storage of collected after collection.In the process of program operation, can manually finish sampling routine, but program can not preserved any data.
Data analysis processing module comprises the functions such as data analysis, data processing, data compression.
Data analysis is for detection of signal time domain, frequency domain and Time-Frequency Analysis.Time-domain analysis mainly obtains following information: for the first time by time of arrival and the amplitude of signal; The time of end echoed signal and amplitude; The time of abnormal signal and amplitude.Frequency-domain analysis provides the frequency component of signal, can obtain the characteristic quantities such as cutoff frequency of excitation mode.Time-Frequency Analysis is based on Short Time Fourier Transform, the time-frequency distributions of picked up signal, and the mode of checking guided wave, determines that judgement provides reference to defect for the mode of abnormal signal.
By seeing cable fracture of wire test experience, guided wave detection of magnetized device is without passing through rejected region, can detect defect at a distance, so distance dependent between guided wave accuracy of detection and defect and magnetizing apparatus, in guided wave sensing range, magnetizing apparatus is the closer to defect, and accuracy of detection is higher, but cannot distinguish fracture of wire at the circumferential distributing position of suspension cable.By cable inspection preliminary test, cable inspection can reach up till now technical indicator is: detect minimum and measure: interior 3.2% the defect that detects of 2m distance; Interior 5.41% the defect that detects of 6m distance; Interior 8.11% the defect that detects of 8m distance.Damage positioning precision: relative errors is in 3%; Absolute error at present ideally instrument reach defect location precision and reach 1-2 wavelength (wavelength equal velocity of wave except excitation frequency).
Cable anchor head cable body testing process is as follows:
The first step: connect power supply by generator, checkout facility situation is also identified field power supply noise.Generator provides alternating current 220V power supply, and supply variation scope is larger, and maximal value reaches 250V, carry out power supply after voltage stabilizing and be stabilized in 220V, and noise is on detecting without impact by voltage stabilizer (600VA).
Second step: first excitation magnetizing apparatus and reception magnetizing apparatus are arranged on to cable to be measured bottom, recycling pocket computer main control system produces the sine wave signal of specific high power low-frequency rate, be input to stimulus sensor, based on magnetostrictive effect, in cable, produce guided wave.
The 3rd step: the detection signal that receives magnetizing apparatus is input to data acquisition unit by gathering port, enters computing machine after A/D converter wherein, machine obtains the guided wave detection signal of cable anchor head cable body after processing as calculated.
The 4th step: by amplitude and the time of arrival of echoed signal, corrosion and damage status and the position of judgement cable anchor head cable body.
Claims (2)
1. for a magnetizing apparatus probe detection system for bridge sling anchor head cable body guided wave Non-Destructive Testing, it is characterized in that, comprise transmitting and receive the excitation magnetizing apparatus of single-point-excitation torsion or longitudinal mode guided wave and receive magnetizing apparatus, detection system main frame; Described excitation magnetizing apparatus is nested with on the close cable of anchor head end at interval respectively with receiving magnetizing apparatus, and by data line, is connected with detection system main frame respectively, and described detection system main frame is an electromagnetic waveguide pick-up unit.
2. a kind of magnetizing apparatus probe detection system for the Non-Destructive Testing of bridge sling anchor head cable body guided wave according to claim 1, it is characterized in that, described detection system main frame comprises the data acquisition unit being connected with reception magnetizing apparatus with filtering and amplifying circuit by prime amplifier, the pocket computer of connection data collecting unit, the signal generating unit being connected with pocket computer, the gating circuit being connected respectively with pocket computer with signal generating unit, the power amplifier being connected respectively with signal generating unit with gating circuit, described excitation magnetizing apparatus is connected with power amplifier.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034803A (en) * | 2014-06-12 | 2014-09-10 | 福建省建筑科学研究院 | Sensing device and monitoring method of active and passive waveguide monitoring bridge cable damage |
| CN105181184A (en) * | 2015-08-06 | 2015-12-23 | 华中科技大学 | Magnetostriction-guide-wave-based measurement apparatus and method of short suspender cable force |
| CN111912907A (en) * | 2020-07-22 | 2020-11-10 | 柳州欧维姆机械股份有限公司 | Intelligent inhaul cable system for evaluating corrosion broken wire and analysis method thereof |
| WO2022052440A1 (en) * | 2020-09-10 | 2022-03-17 | 哈尔滨工业大学（深圳） | Steel wire rope tension defect detection method |
-
2013
- 2013-05-20 CN CN201320273524.9U patent/CN203396752U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034803A (en) * | 2014-06-12 | 2014-09-10 | 福建省建筑科学研究院 | Sensing device and monitoring method of active and passive waveguide monitoring bridge cable damage |
| CN105181184A (en) * | 2015-08-06 | 2015-12-23 | 华中科技大学 | Magnetostriction-guide-wave-based measurement apparatus and method of short suspender cable force |
| CN111912907A (en) * | 2020-07-22 | 2020-11-10 | 柳州欧维姆机械股份有限公司 | Intelligent inhaul cable system for evaluating corrosion broken wire and analysis method thereof |
| CN111912907B (en) * | 2020-07-22 | 2022-11-04 | 柳州欧维姆机械股份有限公司 | Intelligent inhaul cable system for evaluating corrosion broken wire and analysis method thereof |
| WO2022052440A1 (en) * | 2020-09-10 | 2022-03-17 | 哈尔滨工业大学（深圳） | Steel wire rope tension defect detection method |
| US11852610B2 (en) | 2020-09-10 | 2023-12-26 | Harbin Institute Of Technology, Shenzhen | Method for detecting tension force defect of steel cable |
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