GB2502989A - Investigating the propagation of a crack in a rail - Google Patents
Investigating the propagation of a crack in a rail Download PDFInfo
- Publication number
- GB2502989A GB2502989A GB201210352A GB201210352A GB2502989A GB 2502989 A GB2502989 A GB 2502989A GB 201210352 A GB201210352 A GB 201210352A GB 201210352 A GB201210352 A GB 201210352A GB 2502989 A GB2502989 A GB 2502989A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rail
- top surface
- crack
- eddy current
- current sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000463 material Substances 0.000 claims abstract description 43
- 238000005520 cutting process Methods 0.000 claims abstract description 35
- 238000005259 measurement Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 44
- 238000007689 inspection Methods 0.000 claims description 22
- 238000003384 imaging method Methods 0.000 claims description 9
- 238000011835 investigation Methods 0.000 claims description 9
- 238000003860 storage Methods 0.000 claims description 4
- 239000000919 ceramic Substances 0.000 description 3
- 230000002596 correlated effect Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 238000003801 milling Methods 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N19/00—Investigating materials by mechanical methods
- G01N19/06—Investigating by removing material, e.g. spark-testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/08—Testing mechanical properties
- G01M11/081—Testing mechanical properties by using a contact-less detection method, i.e. with a camera
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
- G01M5/0025—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings of elongated objects, e.g. pipes, masts, towers or railways
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
- G01M5/0033—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining damage, crack or wear
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
- G01M5/0091—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by using electromagnetic excitation or detection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/04—Devices for withdrawing samples in the solid state, e.g. by cutting
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N19/00—Investigating materials by mechanical methods
- G01N19/08—Detecting presence of flaws or irregularities
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8803—Visual inspection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
- G01N27/9013—Arrangements for scanning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
- G01N27/9073—Recording measured data
- G01N27/9086—Calibrating of recording device
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
- G01N2203/0062—Crack or flaws
- G01N2203/0066—Propagation of crack
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/0641—Indicating or recording means; Sensing means using optical, X-ray, ultraviolet, infrared or similar detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/0641—Indicating or recording means; Sensing means using optical, X-ray, ultraviolet, infrared or similar detectors
- G01N2203/0647—Image analysis
Abstract
Investigating the propagation of a crack in a rail 12 comprises recording an image of the top surface 20 of the rail and then removing a layer of material from the top surface of the rail. Recording an image of the top surface 20 of the rail 12 and removing a layer of material from the top surface of the rail is repeated a plurality of times. The plurality of images obtained are analysed to track the propagation of the crack through the rail 12. The depth of the crack may be determined by analysing the images to the point where the crack has disappeared and counting the layers of material that have been removed. The image may be recorded by a camera 26 in a fixed position and the layers of material may be removed by a cutting apparatus 24. The rail 12 may be a railway rail. A further embodiment relates to calibrating an eddy current sensor and includes the additional step of running an eddy current sensor over the cracked rail 12 and recording the measurement data.
Description
Method and apparatus for Inspecting tails
Field of the Invention
The present invention concerns a method and apparatus for inspecting rails. More particularly, but not exclusively, this invention concerns a method and apparatus for investigating the propagation of cracks in a railway rail. The invention also concerns a method and apparatus for calibrating a rail inspection system comprising an eddy current sensor.
Background of the Invention -----
Metals cracking under conditions of repeated stress cycling is a well known phenomenon. Eddy current sensors may be used to inspect a metal article for cracks. For example, UK Patent Publication Number GB 2469009 discloses an eddy current sensor that may be used in the railway industry for inspecting rails for cracks. In *the majority of case, a metal article is stressed by repeated pure bending. As a consequence, cracks grow into the material at right angles to the outer surface of the article, However, railway rails are stressed in an extremely complex manner with the result that cracks propagate through the rail at a wide variety of angles to the surface of the rail, for example, between 5 degrees and 25 degrees to the surface, as opposed to 90 degrees as is more conventional. There is no way of predicting what direction a crack will propagate in due to the complexity of the loading as described.
Therefore, while eddy current sensors may detect the presence of a crack in a rail, it may not be possible to accurately determine how the crack has propagated through the rail. This may cause problems when attempting to classify the seriousness of a crack, for example when determining whether or not the section of rail needs replacing. While eddy current systems may be calibrated using a series of notches in a rail test piece, each cut to a different depth by electrical discharge machining, these notches are cut at 90 degrees to the surface of the rail.
As mentioned, crack propagation in a rail is often at angles other than 90 degrees to the surface of the rail, and so such calibration may not be accurate.
Conventional crack propagation investigation techniques may comprise the vertical sectix1ing of a rail, polishing the cut surface, and then taking an image of the polished surface. However, such a technique is time consuming, difficult to control accurately, and expensive.
Additionally, only a single crack may be investigated at a time.
The present invention seeks to mitigate the above- 2C mentioned problems,
Summary of the Invention
The present invention provides, according to a first aspect, a method of investigating the propagation of a crack in a rail, the method comprising the following steps: recording an image of the top surface of the rail, removing a layer of material from the top surface of the rail; repeating the steps of recording an image of the top surface of the rail and removing a layer of material from the top surface of the rail a plurality of times; and analysing the plurality of images obtained to track the propagation of the crack through the rail.
The cross section of a rail typically provides an asymmetric I-beam, comprising a head, a web, and a foot.
The top surface of the rail should be understood to mean the exposed top surface of the head of the rail. Typically this will be the uppermost portion of the rail when the rail has been installed for use, but top surface should not be considered to limit the invention to a rail being disposed in any particular plane. Therefore, while typically the method of inspection will include the rail being disposed with the top surface uppermost, it also covers the rail being disposed on a side during the crack investigation process, so the top surface is in an approximately vertical plane.
The layers of material may be removed in a plane approximately parallel to the plane of the top surface of the rail. Where the top surface of the rail is curved, the layers of material may be removed in a plane approximately tangential to the middle point of the top surface. The layers of material may be removed in an approximately horizontal plane, when the top surface of the rail is the uppermost portion of the rail. The layers of material may be of consistent thickness. For example, each layer of material removed may be 0.2mm thick or 0.5mm thick.
Removing the layers of material at constant thickness may allow the depth of a crack to be determined. The depth of a crack may be determined by analysing the images to the point where the crack is no longer visible, and counting the layers of material that have been removed to get to that point. Removing layers of material of constant thickness allows the depth to be calculated by simple addition.
The analysis of the plurality of images may indicate the direction at which the crack propagates through the rail. Comparison of co-registered images of the rail as the plurality of layers are removed will show the direction of propagation of a crack. This information may also be used to calculate the angle of propagation when combined with the depth information obtained.
The layers of material may be removed by a cutting apparatus. The cutting apparatus may be numerically controlled. The method may include the step of securing the rail to a bed of the cutting apparatus. The rail may be secured such that it cannot move during the removal of material from the top surface. The cutting apparatus ma be a milling machineS. The milling machine may comprise a ceramic cutting head, The layers of material may be removed from the top surface of the rail by the cutting head moving in a transverse direction. The layers of material may be removed from the top surface of the rail by the cutting head moving in a longitudinal direction.
The step of recording an image of the top surface of the rail may comprise taking a photograph of the top surface. The image may be taken by a camera in a fixed position. Taking a plurality of images from a fixed position allows the propagation of the crack through the rail to be accurately tracked as layers of material are removed. The removal of layers from the top surface of the rail may be stopped once the crack no longer propagates through the rail.
The method may include the step of adding a dye penetrant to the crack in order to increase the visual distinctiveness of the crack. The method may comprise the step of magnetic particle inspection of the crack. Such steps may assist in electronic image analysis of the crack propagation -The method may include the step of running an eddy current sensor over the rail. The eddy current sensor may be run over the rail before any layers of material are removed from the top surface of the rail. The eddy current sensor may be run over the rail after each layer of material has been removed from the top surface. The method may include the step of calibrating the eddy current sensor in dependence on the propagation of the crack through the rail as determined by the steps of removing layers of material and image recording. The calibration step may comprise correlating the measured depth of the crack with the response of the eddy current sensor when scanning the crack.
Acbording to a second aspect, the invention provides a rail inspection apparatus configured for investigating the propagation of a crack through a rail comprising: a cutting head configured to remove a plurality of layers from the top surface of a rail; a mounting bed located below the cutting head configured to securely fix a rail in position; imaging apparatus configured to capture images of the top surface of a rail mounted to the mounting bed.
The imaging apparatus may be fixed in position relative to the mounting bed. The rail inspection apparatus may comprise a control means, the control means configured to control the cutting head.
The imaging apparatus may further comprise an image storage means configured to receive and store images captured by the imaging apparatus.
The control means may include the image storage means.
The rail inspection apparatus may include a monitor for displaying images captured by the imaging apparatus.
The rail inspection apparatus may include an eddy current sensor.
According to a third aspect, the invention provides, a method of calibrating an eddy current sensor for inspecting rails, the method comprising the steps of: running an eddy current sensor over a cracked rail and recording the measurement data obtained; recording an image of the top surface of the rail, removing a layer of material from the top surface of the rail; repeating the steps of recording an image of the top surface of the rail and removing a layer of material from the top surface of the rail a plurality of times; analysing the plurality of images obtained to track the propagation of the crack through the rail; and co±relating the data regarding the propagation of the crack through the rail with the measurement data obtained by the eddy current sensor.
It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into pther aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa
Description of the Drawings
Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: Figure 1 shows a schematic view of a rail inspection apparatus according to a first embodiment of the invention and a rail under inspection; Figure 2 shows a schematic view of a rail inspection apparatus as shown in figure 1 with the cutting head substituted with an eddy current sensor; Figure 3 shows an example photograph of a top surface of a rail; Figure 4 shows a photograph of the rail shown in figure 3 with 1.6mm of the top surface removed; Figures 5A to 5S show a series of photographs of the top surface of a rail, with a 0.2mm layer of material removed from the top surface of the rail in each sequential figure; and Figure 6 shows an example top surface of a rail alQng with the readings obtained by an eddy current sensor that has been run along the top surface of that rail.
Detailed Description
Figure 1 shows a schematic view of a rail inspection apparatus 10 according to a first embodiment of the invention and a rail 12 under inspection. The rail 12 may include one or more cracks as will be described and shown in greater detail in the fOllowing figures. The rail 12 comprises a head 14, a web 16 and a foot 18. The head 14 comprises a top surface 20 and the foot 18 of the rail 12 is mouned to a fixing bed 22 of the rail inspection apparatus 10. The apparatus 10 further comprises a numerically controlled ceramic cutting head 24 and a camera 26 mounted in a fixed position above the rail 12. The cutting head 24 and camera 26 are controlled by a control unit 28, which also includes a memory to store images taken by the camera 26.
The cutting head 24 is arranged to move across the top surface 20 of the rail 12 in a traverse direction in comparison to the longitudinal axis of the rail 12, the traverse direction as indicated by the arrow A. As the cutting head 24 moves across the rail 12, it removes a thin section of material from the top surface 20. The cutting head 24 is 100mm in diameter, with the result that a 100mm long section of material is removed from the top surface 20.
The thickness of the layer of material removed may be set by the control unit 28 and may vary according to the preferences of a user. In this particular embodiment, the cutting head 24 is arranged to remove 0.2mm of the top surface 20 per cutting pass. Prior to the first cutting pass, and following each subsequent cutting pass, the camera 26 is arranged to take a photograph of the top surface 20 of the rail 12. The ceramic cutting head 24 allows a very accurate and clean cut to be made across the top surface 20 of the rail as will be seen in the following figures.
The process of investigating the propagation of cracks in the rail is as follows. The camera 26 takes a photograph of the top surface of the rail. This photograph will capture the position of the cracks as they appear prior to the rail being cut. The cutting head 24 then removes 0.2mm of the top surface of the rail 12 with a first cutting pass.
The camera 26 then takes another photograph of the top surface 20 of the rail, in this case showing the position of the cracks 0.2mm further into the rail. This process of cutting passes and subsequent photographing of the top surface is repeated until all of the cracks in the rail 12 have disappeared. The photographs may be used to calculate the depth of a crack, by examining the number of photographs taken before the crack disappears, and counting the number of 0.2mm sections of material have been removed. The photographs may also be used to track the direction of propagation of a crack within the rail by plotting the change of position of the cracks as the various layers of material are removed.
The apparatus as shown in figure 1 may be modified by adding an eddy current sensor as shown in figure 2. The eddy current sensor may be mounted to a standard tool receiving head on the milling machine, replacing the cutting head 24. Such an arrangement will make it easy to add or remove the eddy current sensor to the apparatus as required.
Prior to the first cutting pass, the eddy current sensor may be run over the rail to detect whatever cracks are present.
The rail may include copper boundary markers spaced to provide boundaries for the eddy current sensor readings.
The boundaries may correspond to the part of the rail where the material will be removed by the cutting head. Once the rail has been scanned by the eddy current sensor, the crack investigation process may proceed as described above. The data provided by the crack investigation, depth and direction of crack propagation, may be correlated with the readings obtained by the eddy current sensor. This may provide improved classification of cracks in rails when an eddy current sensor is used in rails in situ, for example,
-
an eddy current sensor as disclosed in U-K patent publication number GB 2469009.
In an alternative embodiment the eddy current sensor may be run over the top surface of the rail after every cutting pass. The plurality of eddy current readings may be correlated with the data provided by the crack investigation as previously described.
Figure 3 shows an example photographic image that may be taken by the camera 26. The top surface of the rail shows a plurality of cracks 40. The copper strips 42 act as location references for the eddy current scan as previously described. Figure 4 shows the same rail with 1.6mm of the top surface removed and the propagation of the cracks 40 through the rail. -Figures 5A to SS shOw a series of photographs taken during a crack investigation process as described, with each photograph taken at 0.2mm steps. It can be seen that the curved top surface of the rail results in a small section being removed initially, with the width of the section increasing as further cutting passes are made. The depth of each crack is calculated from the cutting pass which first cuts the crack to when the crack disappears. This will prevent any errors being created by the initial curve of the top surface.
Figure 6 shows a photographic image of the top surface of a rail, alongside the readings obtained by an eddy current sensor run along the top surface of the rail. The eddy current sensor has 9 channels, each channel connected to an individual sensor, where the individual sensors are spaced transversely across the rail during the scanning processes. As can be seen, the response of the eddy current sensor is affected by the presence of cracks in the top - -1_i -surface of the rail, and the investigation process detailed herein allows the information obtained about the propagation of the cracks to be correlated with the response of the eddy current sensor when run over said cracks..
whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.
The rail inspection method and apparatus may be used to investigate other potential rail defects, such as squats and transverse defects.
Where in the foregoing description, integers or
elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments. .
Claims (24)
- -12 -Claims 1. A method of investigating the propagation of a crack in a rail, the method comprising the following steps: recording an image of the top surface of the rail, removing a layer of material from the top surface of the rail; repeating the steps of recording an image of the top surface of the rail and removing a layer of material from the top surface of the rail a plurality of times; and analysing the plurality of images obtained to track the propagation of the crack through the rail.
- 2. A method as claimed in claim 1, wherein the layers of material are removed in a plane approximately parallel to the plane of the top surface of the rail.
- 3. A method as claimed in claim 1 or claim 2, wherein the layers of material are removed in an approximately horizontal plane.
- 4. A method as claimed in any of claims 1 to 3, wherein the layers of material removed are of consistent thickness.
- 5. A method as claimed in any preceding claim, comprising the step of determining the depth of a crack by analysing the images to the point where the crack has disappeared, and counting the layers of material that have been removed to get to that point.
- 6. A method as claimed in any preceding claim, wherein the layers of material are removed by a cutting apparatus.-13 -
- 7. A method as claimed in any preceding claim, wherein the step of recording an image of the top surface of the rail comprises taking a photograph of the top surface.S
- 8. A method as claimed in any preceding claim, wherein the image is recorded by a camera in a fixed position.
- 9. A method as claimed in any preceding claim, wherein the 13 removal of layers from the top surface of the rail is stopped once the images recorded indicate the crack no longer propagates through the rail.
- 10. A method as claimed in any preceding clalin, further comprising the step of running an eddy current sensor over the top surface of the rail.
- 11. A method as claimed in claim 10, wherein the eddy current sensor is run over the top surface of the rail before any layers of material are removed from the top surface of the rail.
- 12. A method as claimed in claim 10, wherein the eddy current sensor is run over the top surface of the rail after each layer of material has been removed.
- 13. A method as claimed in any of claims 10 to 12, further comprising the step of calibrating the eddy current sensor in dependence on the propagation of the crack through the rail as identified by the investigation process.-
- 14 - 14. A rail inspection apparatus configured for investigating the propagation of a crack through a rail comprising: a cutting head configured to remove a plurality of layers from the top surface of a rail; a mounting bed lccated below the cutting head configured to securely fix a rail in position; imaging apparatus configured to capture images of the top surface of a rail mounted to the mounting bed.
- 15. A rail inspection apparatus as claimed in claim 14, wherein the imaging apparatus is fixed in position relative to the mounting bed.
- 16. A rail inspection apparatus as claimed in claim 14 or 15, further comprising a control means, the control means configured to control the cutting head.
- 17. A rail inspection apparatus as claimed in any of claims 14 to 16, further comprising an image storage means configured to receive and store images captured by the imaging apparatus.
- 18. A rail inspection apparatus as claimed in claim 17, wherein the control means includes the image storage means.
- 19. A rail inspection apparatus as claimed in any of claims 14 to 18, further comprising a monitor for displaying images captured by the imaging apparatus.
- 20. A rail inspection apparatus as claimed in any of calims 14 to 19, further comprising an eddy current sensor.-15 -
- 21. A method of calibrating an eddy current sensor for inspecting rails, the method comprising the steps of: running an eddy current sensor over a cracked rail and recording the measurement data obtained; recording an image of the top surface of the rail, removing a layer of material from the top surface of the rail; repeating the steps of recording an image of the top surface of the rail and removing a layer of material from the top surface of the rail a plurality of times; analysing the plurality of images obtained to track the propagation of the crack through the rail; and correlating the data regarding the propagation of the crack through the rail with the measurement data obtained by the eddy current sensor.
- 22. A method of investigation the propagation of a crack in a rail substantially as herein described with reference to any of Figs. 1 to 6 of the accompanying drawings.
- 23. A rail inspection system substantially as herein described with reference to any of Figs. 1 to 6 of the accompanying drawings.
- 24. A method of calibrating an eddy current sensor as described with reference to any of Figs. 1 to 6 of the accompanying drawings.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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GB201210352A GB2502989A (en) | 2012-06-12 | 2012-06-12 | Investigating the propagation of a crack in a rail |
PCT/GB2013/051483 WO2013186532A1 (en) | 2012-06-12 | 2013-06-05 | Method and apparatus for inspecting rails |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB201210352A GB2502989A (en) | 2012-06-12 | 2012-06-12 | Investigating the propagation of a crack in a rail |
Publications (2)
Publication Number | Publication Date |
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GB201210352D0 GB201210352D0 (en) | 2012-07-25 |
GB2502989A true GB2502989A (en) | 2013-12-18 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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GB201210352A Withdrawn GB2502989A (en) | 2012-06-12 | 2012-06-12 | Investigating the propagation of a crack in a rail |
Country Status (2)
Country | Link |
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GB (1) | GB2502989A (en) |
WO (1) | WO2013186532A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017100665A1 (en) | 2015-12-09 | 2017-06-15 | Massachusetts Materials Technologies Llc | Measurement of material properties under local tensile stress through contact mechanics |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0103141A2 (en) * | 1982-08-12 | 1984-03-21 | Magnaflux Corporation | Surface treating and testing apparatus |
US5673203A (en) * | 1994-10-11 | 1997-09-30 | United Technologies Corporation | Crack monitoring apparatus |
JP2001174413A (en) * | 1999-12-16 | 2001-06-29 | Keisoku Kensa Kk | Method of detecting and displaying surface crack of monorail |
WO2011036330A1 (en) * | 2009-09-28 | 2011-03-31 | Lectorcam, S.L | Device for monitoring and tracking crack propagation |
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AUPN992596A0 (en) * | 1996-05-17 | 1996-06-13 | Technological Resources Pty Limited | Magnetic detection of discontinuities in magnetic materials |
US6563309B2 (en) * | 2001-09-28 | 2003-05-13 | The Boeing Company | Use of eddy current to non-destructively measure crack depth |
GB0800406D0 (en) * | 2008-01-10 | 2008-02-20 | Sperry Rail International Ltd | Sensor assembly |
JP2009216559A (en) * | 2008-03-11 | 2009-09-24 | Hitachi-Ge Nuclear Energy Ltd | Eddy current inspecting device |
-
2012
- 2012-06-12 GB GB201210352A patent/GB2502989A/en not_active Withdrawn
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2013
- 2013-06-05 WO PCT/GB2013/051483 patent/WO2013186532A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0103141A2 (en) * | 1982-08-12 | 1984-03-21 | Magnaflux Corporation | Surface treating and testing apparatus |
US5673203A (en) * | 1994-10-11 | 1997-09-30 | United Technologies Corporation | Crack monitoring apparatus |
JP2001174413A (en) * | 1999-12-16 | 2001-06-29 | Keisoku Kensa Kk | Method of detecting and displaying surface crack of monorail |
WO2011036330A1 (en) * | 2009-09-28 | 2011-03-31 | Lectorcam, S.L | Device for monitoring and tracking crack propagation |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2017100665A1 (en) | 2015-12-09 | 2017-06-15 | Massachusetts Materials Technologies Llc | Measurement of material properties under local tensile stress through contact mechanics |
EP3391020A4 (en) * | 2015-12-09 | 2019-07-24 | Massachusetts Materials Technologies LLC | Measurement of material properties under local tensile stress through contact mechanics |
US11378502B2 (en) | 2015-12-09 | 2022-07-05 | Massachusetts Materials Technologies Llc | Measurement of material properties under local tensile stress through contact mechanics |
Also Published As
Publication number | Publication date |
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GB201210352D0 (en) | 2012-07-25 |
WO2013186532A1 (en) | 2013-12-19 |
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