CN102520068A - Rail destruction detection device and method based on magnetostriction and longitudinal ultrasonic guided wave - Google Patents

Rail destruction detection device and method based on magnetostriction and longitudinal ultrasonic guided wave Download PDF

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Publication number
CN102520068A
CN102520068A CN2011104038822A CN201110403882A CN102520068A CN 102520068 A CN102520068 A CN 102520068A CN 2011104038822 A CN2011104038822 A CN 2011104038822A CN 201110403882 A CN201110403882 A CN 201110403882A CN 102520068 A CN102520068 A CN 102520068A
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coil
rail
guided wave
electromotive force
wave
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CN102520068B (en
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马宏伟
宋振华
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Jinan University
University of Jinan
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Jinan University
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Abstract

The invention discloses a rail damage detection device and method based on magnetostriction and longitudinal ultrasonic guided wave, which are applied in the field of railway traffic nondestructive detection. The rail damage detection device comprises a shell, wherein an inner wire support, an inner coil, an outer wire support, an outer coil, a yoke and a permanent magnet are arranged in the shell; a current input port, an inner coil current input electric wire and an inner coil current output electric wire are arranged at one end of the shell; an outer coil current output electric wire, an outer coil current loop electric wire and a voltage output port are arranged at the other end of the shell; and the upper part of the shell is fixedly connected with a rail detection vehicle. The rail damage detection method comprises the following steps of: exciting induced electromotive force by utilizing magnetostriction and longitudinal ultrasonic guided wave, and indirectly measuring time and strength generated by a defect reflective waveguide signal according to the induced electromotive force, and further determining the destruction position and the destruction size. The rail damage detection device and method can be used for carrying out accurate detection on trace destruction inside and outside the rail, and have the advantages of long detection distance and high detection efficiency.

Description

Rail damage detection apparatus and method based on magnetostriction and longitudinal ultrasonic guided wave
Technical field
The present invention relates to track traffic Non-Destructive Testing field, particularly a kind of rail damage detection apparatus and method thereof based on magnetostrictive technology and longitudinal ultrasonic guided wave technology.
Background technology
Current track traffic Non-Destructive Testing field is to utilize detection meanss such as leakage method, osmosis, eddy-current method that rail is carried out damage check mostly.Simultaneously, people are also using rays method and supercritical ultrasonics technology that the track degree of injury is monitored.What widely use now is track inspection vehicle technology.This detection system mainly is at postposition started track inspection vehicle platform upper set ultrasound wave and electromagnetic induction detection technique and optical sensor.In addition, Britain Imperial College has developed a longitudinal ultrasonic guided wave rail damage check equipment based on piezoelectric sensor.Univ California-San Diego USA's design has also been made a mode of flexural vibration supersonic guide-wave rail damage check equipment based on laser technology.
All there is following defective in various degree respectively in said method:
(1) leakage method, like K.Sawley, the exercise question that R.Reiff. etc. deliver is the article of " An assessment of Railtrack ' s methods for managing broken and defective rail. "; The method rig-site utilization is very simple, can directly detect surface imperfection, but like seized surface of the work coating or humidity is arranged; Detecting reliability will greatly reduce; So necessary first decoating is dried the surface.This has just limited to this method efficient in actual use widely.
(2) osmosis, this method is very high to surperficial openings line detection sensitivity, but has coating and moist workpiece just undesirable to the surface, and the judgement of defective is depended on reviewer's experience, and this can not satisfy the needs of extensive rail damage check.
(3) eddy-current method, this method are to be based upon on the basis of electromagnetic induction, are utilized under the action of alternating magnetic field, and the eddy current that various amplitude and phase place can take place different materials detects the difference of physical property, defective and the structure situation of ferromagnetism and nonferromugnetic material.For ferrimagnet, usually it is magnetized to state of saturation, detect by nonferromugnetic material again.But detection method of eddy and as above two kinds of methods all can only detect the surface or the near surface flaw of metallic conductor, it is very shallow to detect the degree of depth, can't know the damage of rail inside.
(4) rays method is very effective to the detection of defective under the workpiece surface, but the x radiation x harmful to human must carry out security protection during detection, and some operating mode is difficult for implementing.
(5) ultrasonic Detection Method is very effective to the detection of defective under the workpiece surface, but needs couplant when detecting, and efficient is lower, the judgement of defective is also depended on technician's experience.Main is that this method adopts point-to-point metering system; Can only detecting sensor structure in the subrange of below; Fail effectively the longitudinal direction of hyperacoustic energy focusing, so its directionality is not strong, causes detection efficiency low and realize the assessment of degree of injury is difficult to rail.Too short and small for the slow and rail circuit of sensing range of this method detection speed with respect to hundreds and thousands of kilometers.The speed of disposing the track inspection vehicle of ultrasonic equipment is greatly limited by this equipment testing principle.Therefore, as above detection technique combines in the optical detection system, and " data overload " is still a tangible problem.But then, calculate and when handling these data, the method for these mathematics is not good at and is handled the unusual characteristic that occurs in the track, like the crossing of track etc. through mathematical principle.
(6) Britain Imperial College design based on the longitudinal ultrasonic guided wave rail damage check equipment of piezoelectric sensor because piezoelectric sensor need with rail between contact closely; So need position to be detected, rail surface to scribble couplant; This just makes must be kept bright and clean smooth by the position rail of this sensor of cramping; Corrosion can not occur, otherwise be difficult to realize coupling.But the greatest problem of this equipment is a piezoelectric sensor to be excited and receiving device for the contact guided wave, therefore, each detect needed 20 minutes at least and when detecting equipment can not on rail, move, can't be implemented in line loss and hinder detection.This point has restricted detection efficiency greatly for the rail of thousands of kilometers.
(7) though the equipment that Univ California-San Diego USA researched and developed has used contactless laser technology excitation ultrasound guided wave, supersonic guide-wave that should technology excited is a mode of flexural vibration.This mode is compared propagation distance with longitudinal wave guide short, and undesired signal is many.Laser signal amplifier instability and detection signal noise are excessive.Therefore, the track inspection vehicle that this checkout equipment carried only can move detection to rail with the speed of 10 miles per hours, and this efficient still can not satisfy the requirement of extensive rail damage check.
Therefore, need provide a kind of and not only can all accurately detect the damage of rail inside and outside, and high rail damage detection apparatus and the method for detection efficiency.
Summary of the invention
The shortcoming that one object of the present invention is to overcome prior art is with not enough; A kind of rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave is provided; This device can all can accurately detect the damage of rail inside and outside, detects distance, and detection efficiency is high.
Another object of the present invention is to provide a kind of rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave based on said apparatus.
One object of the present invention realizes through following technical scheme: a kind of rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave; Comprise shell; And setting interior layer line holder, inner coil, outer layer line holder, outer coil, yoke, permanent magnet in the enclosure; And the current input terminal mouth, inner coil electric current input electric wire, the inner coil electric current output electric wire that are arranged on shell one end; And the outer coil electric current output electric wire, outer coil current return electric wire, the voltage output end mouth that are arranged on the shell other end, said shell upper is fixedly connected with the rail inspection vehicle; The layer line holder is the rectangular parallelepiped of a lower ending opening in said, and the shape of its lower ending opening position shape and rail rail head is complementary, and inner coil is arranged in the interior layer line holder; Outer layer line holder is arranged on the outside of inner coil; Be fixedly connected with interior layer line holder edge, outer coil is arranged in the outer layer line holder, and yoke is arranged on the outside of outer layer line holder; The inboard edge with outer layer line holder of yoke fixes; Permanent magnet sticks on top, the yoke outside, and permanent magnet top and inboard, shell top fix, and interior layer line holder and yoke bottom all are fixedly installed on the both sides of the edge, shell bottom; Said inner coil and outer coil are plurality of sections and replace both positive and negative polarity coil composition; There are 4 leads said inner coil lower end, imports electric wire with the inner coil electric current for two and links to each other, and two and inner coil electric current output electric wire, current input terminal mouth all are connected with inner coil electric current output electric wire with inner coil electric current input electric wire; There are 4 leads said outer coil lower end, exports electric wire with the outer coil electric current for two and links to each other, and two and outer coil current return electric wire, current input terminal mouth all are connected with outer coil current return electric wire with outer coil electric current output electric wire; Said current input terminal mouth and voltage output end mouth are fixed on the two ends on top, the shell outside respectively; Said current input terminal mouth and external signal generator, voltage output end mouth and external signal treatment facility.
Concrete, in said inner coil and the outer coil diameter of wire by its encourage and frequency and the wavelength of accepting ultrasonic guided wave signals determines.
Concrete, the lead in said inner coil and the outer coil is hard coil or soft circuitry lines, for example can be hard coils such as enameled wire, also can be the soft circuitry lines such as winding displacement of printed circuit board (PCB).
Preferably, every section width that replaces the both positive and negative polarity coil is the half the of supersonic guide-wave wavelength in said inner coil and the outer coil.
Concrete, said external signal generator specifically comprises: be used to produce the waveform generator that detects required electrical signal of the frequency; Be used for power amplifier with the electric signal amplification.
Concrete, said external signal treatment facility specifically comprises: the preposition modulate circuit that is used for electromotive force signal is converted to digital signal; Data acquisition unit; Be used to calculate the processor of damage position and lesion size.
Another object of the present invention realizes through following technical scheme: a kind of rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave; At first the external signal generator produces to detect and uses signal, after amplifying, is input to the current input terminal mouth, and inner coil produces a dynamic magnetic field according to the variation of input signal; Magnetic field with the permanent magnet generation is coupled simultaneously; Inspire along the supersonic guide-wave of rail longitudinal propagation,, can pass a defect reflection signal back in case supersonic guide-wave runs into the rail defective; This defect reflection signal is converted to the alternating magnetic field of this frequency; This alternating magnetic field inspires induction electromotive force in outer coil, come to measure indirectly the time and intensity that the defect reflection guided wave signals produces according to this induction electromotive force, thereby confirms the position of damage and the size of damage.
Specifically may further comprise the steps:
(1) calculates the dispersion curve of rail according to rail model and sectional dimension, select the guided wave centre frequency of the type rail supersonic guide-wave damage check according to dispersion curve;
(2) produce one through waveform generator and detect required electric signal, this electric signal waveform is consistent with detection guided wave waveform and guided wave centre frequency; Then this electric signal is imported power amplifier, electric signal is amplified;
(3) electric signal after will amplifying gets into inner coil through the current input terminal mouth; Each section replaces the both positive and negative polarity coil produces corresponding frequencies in rail under the electric signal effect dynamic magnetic field in the inner coil, and the quiescent biasing magnetic field that this magnetic field and permanent magnet produce is coupled, and makes the magnetized state of object to be detected that the variation under this frequency take place; Make and change on the object to be detected longitudinal size; Be magnetostrictive strain, thus the excitation ultrasound guided wave, and supersonic guide-wave is along the rail longitudinal propagation; Simultaneously; Outer coil through magnetostrictive back wash effect produce one with the corresponding initial induction electromotive force of the supersonic guide-wave that is encouraged, this initial induction electromotive force outputs to the external signal treatment facility through the voltage output end mouth, the external signal treatment facility writes down the size and the generation time of this initial induction electromotive force;
(4) in case there is supersonic guide-wave to run into the rail defective; Can pass a defect reflection signal back; Utilize magnetostrictive back wash effect, can produce an identical alternating magnetic field of frequency with it in the outer coil, this alternating magnetic field inspires one and the corresponding feedback-induced electromotive force of defect reflection guided wave in outer coil; This feedback-induced electromotive force outputs to the external signal treatment facility through the voltage output end mouth, the size and the generation time of this feedback-induced electromotive force of external signal treatment facility record;
(5) according to the relational expression of induction electromotive force and ultrasonic guided wave signals intensity, initial induction electromotive force and the size of feedback-induced electromotive force and the quantitative relationship between induction electromotive force and the ultrasonic guided wave signals intensity; Intensity conversion through initial induction electromotive force and feedback-induced electromotive force is also measured the intensity of defect reflection guided wave signals, thereby confirms the extent of damage; Confirm the quantitative relationship between ultrasonic guided wave signals intensity and the defect size according to the stress wave principle; Simultaneously; Mistiming between the time of the induction electromotive force that produces through defect reflection signal that equipment write down and the time of the induction electromotive force of excitation supersonic guide-wave generation; With the distance of confirming that supersonic guide-wave is propagated in rail, thereby obtain the accurate position that defective exists.
Employed supersonic guide-wave method damage check principle is according to the elastic stress wave propagation principle among the present invention.That is, supersonic guide-wave belongs to a kind of propagation condition of elastic stress wave, and is as shown in Figure 7.Elastic stress wave is along elongate rod architecture (as: rail; When pipeline etc.) propagating; When running into this structure because of physical dimension or the caused wave impedance variation of change in shape; As: have crack 18 in the rail, this cross section, place, crack (can be xsect or oblique section) is when physical dimension changes, and the variation of wave impedance must take place at this section rail.According to the stress wave principle; When in slim-lined construction, being energized longitudinal ultrasonic guided wave 15; When it is transmitted to crack 18; Wave impedance can change, and the longitudinal ultrasonic guided wave 15 of original incident can return to form flaw echo 16 by antireflection part, and part meeting transmission is crossed this cross section continuation propagation and formed transmitted wave 17.Therefore, time of arrival through recording defect reflection wave 16 signals and multiply by the then position that exists of decidable damage of speed that this ripple propagates in rail.The benefit of this principle is, when the small sightless damage of range estimation took place geometrical scale, the variation of its wave impedance was quite huge, to such an extent as to enough cause one can be by oscillograph recording observable defect reflection signal also.So this method is for finding that there is significant meaning in the inner crack of small infant cracking and rail, the probability that greatly reduction accident takes place.
The detection principle of magneto strictive sensor realizes through magneto-striction phenomenon.Its structure as shown in Figure 1 is to place a permanent magnet in the detected material external object to be detected is magnetized, thus it to require object to be detected be ferromagnet.And at object to be detected near surface (noncontact) layout one deck coil (the design's inner coil is 3).When coil feeds the electric current with certain change of frequency; Can in object to be detected, produce the dynamic magnetic field of corresponding frequencies; Coupling takes place in the quiescent biasing magnetic field that this magnetic field and permanent magnet produce, and makes the magnetized state of object to be detected that the variation under this frequency take place, and makes to change on the object to be detected longitudinal size; Be magnetostrictive strain, thus the excitation ultrasound guided wave.Otherwise; Utilize magnetostrictive back wash effect; When the defect reflection signal is passed back; Can produce the dynamic change magnetic field that frequency is identical with it, in coil (outer coil 5 among the present invention), produce induction electromotive force simultaneously, the defective that just can obtain guided wave through the size of outer coil 5 these induction electromotive forces of measurement transmits.Mistiming between the induction electromotive force that the flaw echo that receives through record inner coil 3 pumping signals and outer coil 5 causes, just can confirm the position of damaging.Because certain distance is arranged between coil and the object to be detected; Therefore the benefit of this sensor is to realize to long distance; Ferromagnet carries out contactless damage check on a large scale; And can adapt to higher temperature and bad working environment, be suitable for the online damage check of the rail that the track inspection vehicle is in operation.
The principle of work of apparatus of the present invention is through the permanent magnet in this equipment yoke to be magnetized, thereby around it, produces a quiescent biasing magnetic field, and will be magnetized by the rail of this equipment overlay area.In current feedback circuit, import the AC signal (for example, 10 cycle sinusoidal electric signals of 300KHz Hanning window modulation commonly used) of fixed frequency then through signal generation apparatus.This electric current is laid the rule conduction according to inner coil; Its through galvanomagnetic effect can produce one with the same dynamic magnetic field of institute's galvanization change frequency; The static magnetic field that permanent magnet produces is upset, and the alternate of this frequency takes place in rail surface magnetization state, thereby vertically produces the change in size under this frequency at it; Then motivate the longitudinal ultrasonic guided wave of this frequency, as shown in Figure 3.Reflection takes place and be delivered to this equipment place when the longitudinal ultrasonic guided wave runs into defective; According to magnetostrictive back wash effect principle; The defect reflection signal of this frequency can be converted to the alternating magnetic field of this frequency, and there are quantitative relationship in alternating magnetic field intensity and guided wave signals intensity.Simultaneously, this alternating magnetic field can inspire induction electromotive force in outer coil, and this winding wire is connected with rear end voltage output end mouth induction electromotive force is exported.
There is following funtcional relationship between induction electromotive force and the ultrasonic guided wave signals intensity:
V R ( k , t ) = - 2 πkw μ r 2 λ 2 ns H 0 E | ∫ 0 l f ( ξ ) e jkξ dξ | 2 e - jk ( d - vt ) ;
Wherein k is the supersonic guide-wave wave number, and n is the number of turn of receiving coil, and s is the cross-sectional area of receiving coil, and l is the length of receiving coil, and d is the axial distance between receiving coil and drive coil, and v is a supersonic guide-wave velocity of wave in the ferromagnetic material, μ rFrom being the ferromagnetic material relative permeability, λ is the ferromagnetic material magnetostriction constant, H 0It is the function of coil turn and electric current.
Can confirm the quantitative relationship between the intensity of size and supersonic guide-wave of induction electromotive force through this formula; Simultaneously, can confirm the quantitative relationship between ultrasonic guided wave signals intensity and the rail defect size according to the stress wave principle; And the time that induction electromotive force produces is poor with the time life period of excitation guided wave, this mistiming be guided wave in rail, propagate and run into defect reflection after pass the time that excites the position back.Therefore, can come to measure indirectly the time and intensity that the defect reflection guided wave signals produces through this induction electromotive force of apparatus measures, thereby confirm the position of damage and the size of damage.
The present invention compared with prior art has following advantage and beneficial effect:
The inventive method all is applied to the rail damage check with magnetostrictive technology and longitudinal ultrasonic guided wave method, and the longitudinal ultrasonic guided wave is different from traditional ultrasound wave, and it has very strong directionality, is similar to the difference of laser and normal optical.This detection method is to growing one of method apart from the rod-like structure damage check.Because the supersonic guide-wave that this method is used can be effectively at the rail surface excitation, guided wave can be distributed and in the whole cross section of rail along vertically propagation at a high speed of rail.Therefore this method can not only detect rail cross section major injuries such as rail break, can detect rail surface and inner early stage sightless wire fine crack simultaneously, so this method can improve the efficient of rail damage EARLY RECOGNITION.Fast the speed of propagating in this medium like the velocity of sound owing to guided wave simultaneously in the speed of propagating in the medium, so this detection method efficient is high.This method good directionality, penetration capacity is strong, energy high (energy is greater than sound wave) and comparatively concentrated.The detection principle of magneto strictive sensor realizes through magneto-striction phenomenon.The benefit of this sensor is to realize the long distance contactless damage check of ferromagnet on a large scale, and can adapt to higher temperature and bad working environment, is suitable for the online damage check of the rail that the track inspection vehicle is in operation.Not only can check the geometry flatness that rail is surperficial through the two combination, can find rail surface and inner fine crack and nuclear wound simultaneously, can find the rail earlier damage effectively, the accident probability that reduction causes because of reasons such as rail damage or fractures.This method detects distance, and detection efficiency is high.Each excitation ultrasound guided wave only needs the hundreds of microsecond with the completion damage check, so this equipment can carry the online damage check that on the track inspection vehicle, realizes rail.
Description of drawings
Fig. 1 is apparatus of the present invention mechanical part structural representation;
Fig. 2 is a STRUCTURE DECOMPOSITION synoptic diagram shown in Figure 1;
Fig. 3 is that inner coil of the present invention and circuit connecting mode reach and interior layer line holder putting position synoptic diagram;
Fig. 4 is the circuit theory synoptic diagram of inner coil of the present invention and current feedback circuit;
Fig. 5 is that outer coil of the present invention and circuit connecting mode reach and outer layer line holder putting position synoptic diagram;
Fig. 6 is the circuit theory synoptic diagram of outer coil of the present invention and voltage sensor;
Fig. 7 is a longitudinal ultrasonic guided wave damage check principle schematic;
Fig. 8 is a magnetostriction excitation supersonic guide-wave principle schematic in the rail;
Fig. 9 is apparatus of the present invention operating process synoptic diagram;
Figure 10 is the schematic appearance when apparatus of the present invention are used among the embodiment;
Figure 11 is a signal graph measured in the embodiment of the invention.
Among Fig. 2: the 1-rail; The holder of 2-line; The 3-inner coil; The outer layer line holder of 4-; 5 outer coils, 6-yoke, 7-permanent magnet, 8 shells, 9-current input terminal mouth, 10-electrical inner layer coil current input electric wire, 11-inner coil electric current output electric wire, 12-outer coil electric current output electric wire, 13-outer coil current return electric wire, 14-voltage output end mouth.
Among Fig. 4: -inner coil replaces the coil that both positive and negative polarity is arranged for first section; -inner coil replaces the coil that both positive and negative polarity is arranged for second section; -be arranged in inner coil bottom left lead that links to each other with front end inner coil electric current input electric wire; -be arranged in inner coil bottom left lead that links to each other with front end inner coil electric current output electric wire; -be arranged in inner coil bottom, right side lead that links to each other with front end inner coil electric current input electric wire; -be arranged in inner coil bottom, right side lead that links to each other with front end inner coil electric current output electric wire.
Among Fig. 6: -outer coil replaces the coil that both positive and negative polarity is arranged for first section; -outer coil replaces the coil that both positive and negative polarity is arranged for second section; -be arranged in outer coil bottom left lead that links to each other with rear end outer coil current return electric wire; -be arranged in outer coil bottom left lead that links to each other with rear end outer coil electric current output electric wire; -be arranged in outer coil bottom, right side lead that links to each other with rear end outer coil electric current output electric wire; -be arranged in outer coil bottom, right side lead that links to each other with rear end outer coil electric current current return electric wire.
Among Fig. 7: the longitudinal ultrasonic guided wave of 15-incident; The 16-flaw echo; The 17-transmitted wave; The 18-crack.
Among Fig. 8: the AC signal of the fixed frequency that 19-imports in current feedback circuit through signal generation apparatus.
Among Fig. 9: rail damage detection apparatus mechanical part among 20-the present invention.
Among Figure 10: first first defective preset of 21-at flange of rail bearing position; Second first defective preset of 22-at flange of rail bearing position; The 3rd first defective preset of 23-at flange of rail bearing position.
Among Figure 11: the initial induction electromotive force of 24-oscillograph recording; The feedback-induced electromotive force of defective 23 correspondences of 25-oscillograph recording; The feedback-induced electromotive force of defective 22 correspondences of 26-oscillograph recording; The feedback-induced electromotive force of defective 21 correspondences of 27-oscillograph recording; The induction electromotive force that 28-end reflections signal is corresponding.
Embodiment
Below in conjunction with embodiment and accompanying drawing the present invention is described in further detail, but embodiment of the present invention is not limited thereto.
Embodiment 1
A kind of rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave, it has the detection distance, and detection time is short, detects in real time in the contactless track inspection vehicle on-line operation, and can find advantage such as rail infant cracking damage.Its mechanical part is as shown in Figure 1.Its outward appearance is the rectangular parallelepiped of a lower ending opening, and lower ending opening position shape is similar with the shape of rail rail head, will be slightly than rail greatly to guarantee the noncontact of itself and rail; Top is connected with the track inspection vehicle.It comprises interior layer line holder 2, inner coil 3, outer layer line holder 4, outer coil 5, yoke 6, permanent magnet 7, shell 8, current input terminal mouth 9, electrical inner layer coil current input electric wire 10, inner coil electric current output electric wire 11, outer coil electric current output electric wire 12, outer coil current return electric wire 13, voltage output end mouth 14, and is specifically as shown in Figure 2.Interior layer line holder 2 is positioned on the shell 8 and fixes.Inner coil 3 is positioned in the interior layer line holder 2, and is connected with inner coil electric current input electric wire 10, inner coil electric current output electric wire 11 and current input terminal mouth 9, and method of attachment is as shown in Figure 3.Its circuit theory is as shown in Figure 4; Inner coil 3 is divided into plurality of sections and replaces the both positive and negative polarity coil; Present embodiment is illustrated as three sections; section and arranged alternate; In inner coil 3 lower ends 4 leads are arranged; Line links to each other with leading portion end layer line loop current input electric wire 10; Line links to each other with inner coil electric current output electric wire 11, and two electric wires link to each other with current input terminal mouth 9.According to the position that electric current input and output electric wire is put, each section coil alternative current direction.That is: first section coil right-hand member is connected with line ; Line links to each other 10 with inner coil input electric wire; Left end is connected with line ; Line links to each other with inner coil electric current output electric wire 11 again; Realize that electric current conducts from right to left, wherein dotted arrow is represented the direction of current conduction of first section coil ; Second section coil then left end is connected with line ; Line links to each other with inner coil input electric wire 10 again; Right-hand member is connected with line ; Line links to each other with inner coil electric current output electric wire 11 again; Realize that electric current conducts from left to right, solid arrow is represented direction of current in second section coil among the figure; The 3rd section coil and first section coil one appearance are for repeating first section connection method.As shown in Figure 2, on layer line holder 2 edges, the external layer line holder 4 in edge of layer line holder 2 was played a supporting role in making in outer layer line holder 4 was placed on.Outer coil 5 is arranged in the outer layer line holder 4, as shown in Figure 5, and be connected 14 with rear end outer coil electric current output electric wire 12, outer coil current return electric wire 13 and back segment voltage sensor, as shown in Figure 6.Outer coil 5 itself does not feed electric current; It can produce induction electromotive force in coil because of changes of magnetic field; It is divided into plurality of sections and replaces the both positive and negative polarity coil and (be illustrated as three sections; section and arranged alternate), electric current is positive and negative in the same alternate coils section with the method for attachment of inner coil and lead of circuit connecting method and the coil segment .The physical circuit method of attachment is as shown in Figure 5.Solid line is represented the direction of current of outer coil section among the figure, and dotted line is represented the direction of current in the outer coil section .As shown in Figure 2, inner coil 3 is realized insulated separation through outer layer line holder 4 and outer coil 5.Yoke 6 inboard edges with outer layer line holder 4 fix, and through the edge of outer layer line holder 4 it are played the support effect; Simultaneously, both sides, yoke 6 bottom are placed on the both sides of the edge, shell 8 bottom, and through both sides of the edge, shell bottom it are played fixing and supporting role.Permanent magnet 7 is pasted with yoke 6 mutually, to realize magnetic property.Simultaneously, permanent magnet 7 tops and inboard, shell 8 top fix, and through shell 8 it are realized constraint.In addition, said current input terminal mouth 9 and voltage output end mouth 14 are fixed on the two ends on top, the shell outside respectively, and be as shown in Figure 1.
What deserves to be mentioned is; The inner coil 3 in this equipment synoptic diagram and the lead thickness and the density degree of outer coil 5 are merely signal; Real winding wire is compact arranged; The diameter of lead by its encourage and accept frequency and the wavelength decision of ultrasonic guided wave signals; In addition every section alternately the width of both positive and negative polarity coil be the half the of supersonic guide-wave wavelength, promptly the section of among Fig. 4 with section of among section, Fig. 6 section is the half the of supersonic guide-wave wavelength with .Lead can be hard coils such as enameled wire, also can be the soft circuitry lines such as winding displacement of printed circuit board (PCB).
A kind of rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave based on said apparatus; At first the external signal generator produces to detect and uses signal; After amplifying, signal is input to the current input terminal mouth of this equipment from the signal output port of signal amplifier through lead; Inner coil produces a dynamic magnetic field according to the variation of input signal, and the magnetic field with the permanent magnet generation is coupled simultaneously, inspires along the supersonic guide-wave of rail longitudinal propagation; In case supersonic guide-wave runs into the rail defective; Can pass a defect reflection signal back, this defect reflection signal is converted to the alternating magnetic field of this frequency, and this alternating magnetic field inspires induction electromotive force in outer coil.
Specifically may further comprise the steps:
(1) obtains the dispersion curve of rail according to rail model and sectional dimension through the GUIGUW computed in software, select to be fit to the guided wave centre frequency of the type rail supersonic guide-wave damage check according to dispersion curve;
(2) produce one through waveform generator and detect required electric signal, this electric signal waveform is consistent with detection guided wave waveform and centre frequency; This electric signal is imported power amplifier, electric signal is amplified;
(3) as shown in Figure 9; Electric signal after amplifying is got into inner coil through the current input terminal mouth; Each section replaces the both positive and negative polarity coil produces corresponding frequencies in rail under the electric signal effect dynamic magnetic field in the inner coil, and the quiescent biasing magnetic field that this magnetic field and permanent magnet produce is coupled, and makes the magnetized state of object to be detected that the variation under this frequency take place; Make and change on the object to be detected longitudinal size; Be magnetostrictive strain, thus the excitation ultrasound guided wave, and supersonic guide-wave is along the rail longitudinal propagation.At this moment, outer coil through magnetostrictive back wash effect produce one with the corresponding induction electromotive force of the supersonic guide-wave that is encouraged.This induction electromotive force is through the output of voltage output end mouth.Voltage output end mouth and external signal treatment facility connect through lead like oscillographic signal input port, write down the size and the generation time of initial induction electromotive force through the external signal treatment facility, like signal among Figure 11 24;
(4) be provided with defective in the present embodiment on the rail in advance; Shown in figure 10; In case the supersonic guide-wave along the rail longitudinal propagation runs into the rail defective, can pass a defect reflection signal back, utilize magnetostrictive back wash effect; Can produce an identical alternating magnetic field of frequency with it in the outer coil, this alternating magnetic field inspires another and the corresponding feedback-induced electromotive force of defect reflection guided wave in outer coil.This feedback-induced electromotive force is through the output of voltage output end mouth.Voltage output end mouth and external signal treatment facility connect through lead like oscillographic signal input port, through the size and the generation time of external signal treatment facility record feedback-induced electromotive force, like the signal among Figure 11 25,26,27;
(5) owing to there is following funtcional relationship between induction electromotive force and the ultrasonic guided wave signals intensity:
V R ( k , t ) = - 2 πkw μ r 2 λ 2 ns H 0 E | ∫ 0 l f ( ξ ) e jkξ dξ | 2 e - jk ( d - vt ) ;
Wherein k is the supersonic guide-wave wave number, and n is the number of turn of receiving coil, and s is the cross-sectional area of receiving coil, and l is the length of receiving coil, and d is the axial distance between receiving coil and drive coil; V is a supersonic guide-wave velocity of wave in the ferromagnetic material, μ rFrom being the ferromagnetic material relative permeability, λ is the ferromagnetic material magnetostriction constant, H 0It is the function of coil turn and electric current.
Can confirm the quantitative relationship between the intensity of size and supersonic guide-wave of induction electromotive force through this formula; Intensity conversion through initial induction electromotive force and feedback-induced electromotive force is also measured the intensity of defect reflection guided wave signals, thereby can confirm the extent damaged.Simultaneously, can confirm the quantitative relationship between ultrasonic guided wave signals intensity and the rail defect size according to the stress wave principle; And the time that induction electromotive force produces is poor with the time life period of excitation guided wave, this mistiming be guided wave in rail, propagate and run into defect reflection after pass the time that excites the position back.Therefore, can come to measure indirectly the time and intensity that the defect reflection guided wave signals produces through this induction electromotive force of apparatus measures, thereby confirm the position of damage and the size of damage.
In the present embodiment, in the said step (1), it is the 10 cycle sinusoidal electric signals of centre frequency as the modulation of 375KHz Hanning window that signal is used in the detection of generation.The rail length that adopts test to use in the step (4) is 2 meters.Adopt each defective locations after these apparatus and method are tested to be: the defective 1 at flange of rail bearing position is 1.65 meters apart from the guided wave transmitting terminal.The defective 2 at flange of rail bearing position is 1.1 meters apart from the guided wave transmitting terminal.The defective 3 at flange of rail bearing position is 0.55 meter apart from the guided wave transmitting terminal.Through the comparison and detection position of Figure 11 and actual prefabricated defective as a result, prove that fully this method can realize accurately locating defective, error is merely the millimeter level.Simultaneously, can find out from monitoring result Figure 11 that 2 meters whole testing processes of long rail are 0.1 millisecond of time spent only, the efficient and pinpoint accuracy of visible this detection method.
The foregoing description is a preferred implementation of the present invention; But embodiment of the present invention is not restricted to the described embodiments; Other any do not deviate from change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; All should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (9)

1. based on the rail damage detection apparatus of magnetostriction and longitudinal ultrasonic guided wave; It is characterized in that; Comprise shell; And setting interior layer line holder, inner coil, outer layer line holder, outer coil, yoke, permanent magnet in the enclosure; And the current input terminal mouth, inner coil electric current input electric wire, the inner coil electric current output electric wire that are arranged on shell one end, and the outer coil electric current output electric wire, outer coil current return electric wire, the voltage output end mouth that are arranged on the shell other end, said shell upper is fixedly connected with the rail inspection vehicle; The layer line holder is the rectangular parallelepiped of a lower ending opening in said, and the shape of its lower ending opening position shape and rail rail head is complementary, and inner coil is arranged in the interior layer line holder; Outer layer line holder is arranged on the outside of inner coil; Be fixedly connected with interior layer line holder edge, outer coil is arranged in the outer layer line holder, and yoke is arranged on the outside of outer layer line holder; The inboard edge with outer layer line holder of yoke fixes; Permanent magnet sticks on top, the yoke outside, and permanent magnet top and inboard, shell top fix, and interior layer line holder and yoke bottom all are fixedly installed on the both sides of the edge, shell bottom; Said inner coil and outer coil are plurality of sections and replace both positive and negative polarity coil composition; There are 4 leads said inner coil lower end, imports electric wire with the inner coil electric current for two and links to each other, and two and inner coil electric current output electric wire, current input terminal mouth all are connected with inner coil electric current output electric wire with inner coil electric current input electric wire; There are 4 leads said outer coil lower end, exports electric wire with the outer coil electric current for two and links to each other, and two and outer coil current return electric wire, current input terminal mouth all are connected with outer coil current return electric wire with outer coil electric current output electric wire; Said current input terminal mouth and voltage output end mouth are fixed on the two ends on top, the shell outside respectively; Said current input terminal mouth links to each other with the external signal generator, and the voltage output end mouth links to each other with the external signal treatment facility.
2. the rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave according to claim 1 is characterized in that, in said inner coil and the outer coil diameter of wire by its encourage and accept frequency and the wavelength decision of ultrasonic guided wave signals.
3. the rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave according to claim 2 is characterized in that, the lead in said inner coil and the outer coil is hard coil or soft circuitry lines.
4. the rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave according to claim 3 is characterized in that, every section width that replaces the both positive and negative polarity coil is the half the of supersonic guide-wave wavelength in said inner coil and the outer coil.
5. the rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave according to claim 1 is characterized in that, said external signal generator specifically comprises: be used to produce the waveform generator that detects required electrical signal of the frequency; Be used for power amplifier with the electric signal amplification.
6. the rail damage detection apparatus based on magnetostriction and longitudinal ultrasonic guided wave according to claim 1 is characterized in that, said external signal treatment facility specifically comprises: the preposition modulate circuit that is used for electromotive force signal is converted to digital signal; Data acquisition unit; Be used to calculate the processor of damage position and lesion size.
7. based on the rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave of the described device of claim 1, it is characterized in that at first the external signal generator produces to detect and uses signal; After amplifying, be input to the current input terminal mouth; Inner coil produces a dynamic magnetic field according to the variation of input signal, and the magnetic field with the permanent magnet generation is coupled simultaneously, inspires along the supersonic guide-wave of rail longitudinal propagation; In case supersonic guide-wave runs into the rail defective; Can pass a defect reflection signal back, this defect reflection signal is converted to the alternating magnetic field of this frequency, and this alternating magnetic field inspires induction electromotive force in outer coil; Come to measure indirectly the time and intensity that the defect reflection guided wave signals produces according to this induction electromotive force, thereby confirm the position of damage and the size of damage.
8. the rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave according to claim 7 is characterized in that, specifically may further comprise the steps:
(1) calculates the dispersion curve of rail according to rail model and sectional dimension, select the guided wave centre frequency of the type rail supersonic guide-wave damage check according to dispersion curve;
(2) produce one through waveform generator and detect required electric signal, this electric signal waveform is consistent with detection guided wave waveform and guided wave centre frequency; Then this electric signal is imported power amplifier, electric signal is amplified;
(3) electric signal after will amplifying gets into inner coil through the current input terminal mouth; Each section replaces the both positive and negative polarity coil produces corresponding frequencies in rail under the electric signal effect dynamic magnetic field in the inner coil, and the quiescent biasing magnetic field that this magnetic field and permanent magnet produce is coupled, and makes the magnetized state of object to be detected that the variation under this frequency take place; Make and change on the object to be detected longitudinal size; Be magnetostrictive strain, thus the excitation ultrasound guided wave, and supersonic guide-wave is along the rail longitudinal propagation; Simultaneously; Outer coil through magnetostrictive back wash effect produce one with the corresponding initial induction electromotive force of the supersonic guide-wave that is encouraged, this initial induction electromotive force outputs to the external signal treatment facility through the voltage output end mouth, the external signal treatment facility writes down the size and the generation time of this initial induction electromotive force;
(4) in case there is supersonic guide-wave to run into the rail defective; Can pass a defect reflection signal back; Utilize magnetostrictive back wash effect, can produce an identical alternating magnetic field of frequency with it in the outer coil, this alternating magnetic field inspires one and the corresponding feedback-induced electromotive force of defect reflection guided wave in outer coil; This feedback-induced electromotive force outputs to the external signal treatment facility through the voltage output end mouth, the size and the generation time of this feedback-induced electromotive force of external signal treatment facility record;
(5) according to the relational expression of induction electromotive force and ultrasonic guided wave signals intensity, initial induction electromotive force and the size of feedback-induced electromotive force and the quantitative relationship between induction electromotive force and the ultrasonic guided wave signals intensity; Intensity conversion through initial induction electromotive force and feedback-induced electromotive force is also measured the intensity of defect reflection guided wave signals, thereby confirms the extent of damage; Confirm the quantitative relationship between ultrasonic guided wave signals intensity and the defect size according to the stress wave principle; Simultaneously; Mistiming between the time of the induction electromotive force that produces through defect reflection signal that equipment write down and the time of the induction electromotive force of excitation supersonic guide-wave generation; With the distance of confirming that supersonic guide-wave is propagated in rail, thereby obtain the accurate position that defective exists.
9. the rail damage detecting method based on magnetostriction and longitudinal ultrasonic guided wave according to claim 8 is characterized in that, has following funtcional relationship in the step (5) between induction electromotive force and the ultrasonic guided wave signals intensity:
V R ( k , t ) = - 2 πkw μ r 2 λ 2 ns H 0 E | ∫ 0 l f ( ξ ) e jkξ dξ | 2 e - jk ( d - vt ) ;
Wherein k is the supersonic guide-wave wave number, and n is the number of turn of receiving coil, and s is the cross-sectional area of receiving coil, and l is the length of receiving coil, and d is the axial distance between receiving coil and drive coil, and v is a supersonic guide-wave velocity of wave in the ferromagnetic material, μ rFrom being the ferromagnetic material relative permeability, λ is the ferromagnetic material magnetostriction constant, H 0It is the function of coil turn and electric current.
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CN102865953A (en) * 2012-10-10 2013-01-09 北京理工大学 Precision clamping device for online ultrasonic detection of steel rail residual stress
CN102955004A (en) * 2012-10-31 2013-03-06 同济大学 Subway tunnel segment service performance detection method based on wave velocity determination
CN103512955A (en) * 2013-09-25 2014-01-15 暨南大学 Ultrasonic guided-wave method for identifying inclined crack of steel rail by using chaotic oscillator system
CN103529131A (en) * 2013-10-18 2014-01-22 国家电网公司 Adjustable magnetostrictive waveguide sensor
CN103529131B (en) * 2013-10-18 2015-12-02 国家电网公司 A kind of adjustable magnetostrictive waveguide sensor
CN103675099A (en) * 2013-12-16 2014-03-26 杭州浙大精益机电技术工程有限公司 Rail flange defect monitoring system and method based on magnetostrictive torsional guided waves
CN103675099B (en) * 2013-12-16 2016-05-04 杭州浙达精益机电技术股份有限公司 Reverse the flange of rail defect inspection system and method for guided wave based on magnetostriction
CN105136913A (en) * 2015-09-22 2015-12-09 杭州浙达精益机电技术股份有限公司 Magnetostrictive shearing guided wave energy converter for steel rail bottom defect detection
CN105571751B (en) * 2015-12-14 2018-02-13 中国铁路总公司 Gapless rail stress detection device and method based on supersonic guide-wave linear array
CN105571751A (en) * 2015-12-14 2016-05-11 中国铁路总公司 Seamless steel rail stress detection device and method based on ultrasonic guided-wave linear array
CN106320113A (en) * 2016-08-22 2017-01-11 合肥德泰科通测控技术有限公司 Railway field detection device
CN107941898A (en) * 2017-11-16 2018-04-20 北京工业大学 The cable wire defect and stress of a kind of magnetosonic multiplexing are detecting device integrated
CN108037186A (en) * 2017-11-29 2018-05-15 沈阳工业大学 The passive rail failure detector of magnetostrictive thin film formula
CN108037186B (en) * 2017-11-29 2021-01-22 沈阳工业大学 Magnetostrictive film type passive rail flaw detection device
CN108956772A (en) * 2018-07-20 2018-12-07 芜湖市联网汇通电子科技有限公司 A kind of underground railway track detection device and its application method
CN109187752A (en) * 2018-10-11 2019-01-11 哈尔滨工业大学(深圳) Detect the magnetostrictive guided-wave sensor and its detection method of elevator traction steel band

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