[go: up one dir, main page]

GB2421075A - Optical-fibre interstice displacement sensor - Google Patents

Optical-fibre interstice displacement sensor Download PDF

Info

Publication number
GB2421075A
GB2421075A GB0427051A GB0427051A GB2421075A GB 2421075 A GB2421075 A GB 2421075A GB 0427051 A GB0427051 A GB 0427051A GB 0427051 A GB0427051 A GB 0427051A GB 2421075 A GB2421075 A GB 2421075A
Authority
GB
United Kingdom
Prior art keywords
displacement
sensor
interstice
translation member
strain
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Withdrawn
Application number
GB0427051A
Other versions
GB0427051D0 (en
Inventor
Ian Richard Peirce
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Insensys Ltd
Original Assignee
Insensys Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Insensys Ltd filed Critical Insensys Ltd
Priority to GB0427051A priority Critical patent/GB2421075A/en
Publication of GB0427051D0 publication Critical patent/GB0427051D0/en
Publication of GB2421075A publication Critical patent/GB2421075A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00Measuring force or stress, in general
    • G01L1/24Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
    • G01L1/242Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/16Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
    • G01B11/165Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge by means of a grating deformed by the object
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/16Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
    • G01B11/18Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Transform (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

Interstice displacement sensing apparatus 10 comprising an interstice displacement sensor 12, optical fibre grating strain sensor interrogation apparatus 14 and processing means 16, operable to determine a change in the size and/or configuration of a crack 18 in a structural member 20. The interstice displacement sensor 12 comprises a displacement translation member 22, in the form of a curved strip of flexible material, first and second fibre Bragg grating (FBG) strain sensors 24, 26, and fixing means 28, 30. The FBG strain sensors 24, 26 are respectively coupled to the displacement translation member 22 at first and second measurement locations 22a, 22b. The sensor 12 can detect a change in the size and/or configuration of the crack 18 due to movement of the crack within the plane of the crack (arrow A) and/or due to movement of the crack within a generally perpendicular plane of (arrow B).

Description

Interstice displacement sensor and sensing apparatus The invention relates
to an interstice displacement sensor and to interstice displacement sensing apparatus incorporating the sensor.
The civil engineering industry requires changes in interstices, such as cracks within structural members and joins between structural members, to be measured and monitored. In the case of cracks, such as a crack in the middle of a concrete structure, the propagation of a crack across the structural member may need to be monitored. In the case of joins, such as expansion gaps between road bridge sections, any relative movement of the gap between bridge sections may need to be measured and/or monitored. Changes in cracks and joins must often be monitored at a large number of locations across a structure.
A known approach for monitoring crack displacement is the use of electrical or optical fibre Bragg grating based strain gauges located across a crack to be monitored. These strain sensors are directly or indirectly bonded to the structure across the crack, and are located within the plane of the crack. Movement of a structural member perpendicular to a crack has been measured using a cantilever beam, having strain sensors coupled to it, located across the crack.
According to a first aspect of the present invention there is provided an interstice displacement sensor comprising: a displacement translation member of curved configuration, to be located across an interstice to be monitored; a first strain sensor coupled to the displacement translation member at a first measurement location; wherein, a change in the size or configuration of the interstice being monitored is related to a displacement of one or more structural elements defining the interstice, such displacement causing a change in the bend induced strain conditions existing within the displacement translation member at the measurement location, thereby changing the strain conditions experienced by the strain sensor.
The interstice displacement sensor preferably further comprises a second strain sensor coupled to the displacement translation member at a second measurement location, wherein a change in the size or configuration of the interstice being monitored is related to a displacement of one or more structural elements defining the interstice, such displacement causing a change in the axial strain and/or bend induced strain conditions existing within the displacement translation member at one or both measurement locations, thereby changing the strain conditions experienced by the or each respective strain sensor.
The interstice displacement sensor may additionally comprise a secondary displacement translation member of curved configuration, to be located across the interstice to be monitored, and third and fourth strain sensors respectively coupled to the secondary displacement translation member at first and second measurement locations, the secondary displacement translation member being arranged generally perpendicularly to the displacement translation member.
The or each strain sensor preferably comprises an optical fibre strain sensor. The or each optical fibre strain sensor preferably comprises a fibre grating strain sensor. The fibre grating strain sensor may be a fibre Bragg grating or may be a fibre Bragg grating Fabry-Perot etalon.
The or each displacement translation member preferably comprises a strip of a flexible material having a curved configuration. The or each displacement translation member preferably comprises a generally n-shaped strip of a flexible material, such as carbon fibre composite material, and most preferably comprises a generally sine curve shaped strip of a flexible material.
The or each displacement translation member may alternatively comprise a generally corkscrew shaped strip of a flexible material, such as carbon fibre composite material.
The strain sensors are preferably provided at first and second spaced locations along the displacement translation member.
Preferably, the strain conditions within the displacement translation member at each measurement location are substantially uniform along the length of the respective grating.
The interstice displacement sensor preferably additionally comprises fixing means provided at each end of the or each displacement translation member, for fixing the or each displacement translation member at each end to the or each structural member defining the interstice.
The interstice displacement sensor may further comprise first and second bridging elements to be respectively provided at each end of the or each displacement translation member. Each bridging element preferably comprises a strip of material having a high modulus of elasticity.
The interstice displacement sensor may further comprise a temperature sensor provided on the or each displacement translation member. The temperature sensor is preferably an optical fibre temperature sensor. The optical fibre temperature sensor preferably comprises a fibre grating temperature sensor. The fibre grating temperature sensor may be a fibre Bragg grating or may be a fibre Bragg grating Fabry-Perot etalon.
Accord ing to a second aspect of the invention there is provided interstice displacement sensing apparatus comprising: an interstice displacement sensor according to the first aspect of the invention; strain sensor interrogation apparatus operable to interrogate the strain sensors; and processing means operable to determine a change in the size and/or configuration of an interstice being measured from measurement information received from the interrogation apparatus.
Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic representation of interstice displacement sensing apparatus according to a first embodiment of the invention; Figure 2a is a diagrammatic side view of the displacement translation member of Figure 1 at zero interstice displacement; Figure 2b is a diagrammatic side view of the displacement translation member of Figure 1 at a positive interstice displacement in the plane of the interstice; Figure 3a is a diagrammatic side view of the displacement translation member of Figure 1 at zero interstice displacement; Figure 3b is a diagrammatic side view of the displacement translation member of Figure I at a positive interstice displacement in a perpendicular plane to the plane of the interstice; Figure 4 is a diagrammatic representation of an interstice displacement sensor according to a second embodiment of the invention; Figure 5 is a diagrammatic representation of an interstice displacement sensor according to a third embodiment of the invention; Figure 6 is a diagrammatic representation of an interstice displacement sensor according to a fourth embodiment of the invention; Figure 7 is a diagrammatic representation of an interstice displacement sensor according to a fifth embodiment of the invention; and Figure 8 is a diagrammatic representation of an interstice displacement sensor according to a sixth embodiment of the invention.
Referring to Figure 1, interstice displacement sensing apparatus 10 according to a first embodiment of the invention comprises an interstice displacement sensor 12, strain sensor interrogation apparatus 14 and processing means 16, operable to determine a change in the size and/or configuration of the interstice, which in this example comprises a crack 18 in a concrete structural member 20 (only part of which is shown for clarity).
In this example the interstice displacement sensor 12 comprises a displacement translation member 22, a first strain sensor 24, a second strain sensor 26 and fixing means 28, 30.
The displacement translation member 22 takes the form of a strip of flexible moulded carbon fibre composite material which is generally sine curved in shape. The end sections of the displacement translation member 22 have a radius of curvature R(0).
The first and second strain sensors 24, 26 each comprise an optical fibre Bragg grating (FBG) strain sensor having a resonant wavelength of 1 550nm and a linewidth of 7Opm.
The first FBG strain sensor 24 is provided at a first measurement location 22a on the displacement translation member 22 and the second FBG strain sensor 26 is provided at a second measurement location 22b. The measurement locations 22a, 22b have been selected such that the strain conditions experienced by the respective FBG strain sensors 24, 26 are substantially uniform along the length of each FBG 24, 26.
The FBG strain sensors 24, 26 are provided within an optical fibre 32 which is bonded to the upper surface of the displacement translation member 22. It will be appreciated that the FBG strain sensors 24, 26 may alternatively be bonded to the lower surface or may be embedded within the displacement translation member 22.
Fixing means 28, 30 are provided at each end of the displacement translation member 22 for securely fixing the displacement translation member 22 to the structural member 20 on either side of the crack 18.
The strain sensor interrogation apparatus 14 here takes the form of an optical fibre grating interrogation apparatus. The design and operation of suitable optical fibre grating interrogation apparatus will be well known to the person skilled in the art, and so will not be described in detail here. One particularly suitable optical fibre grating interrogation apparatus is described in the applicant's co-pending PCT application The output from the optical fibre grating interrogation apparatus 14 is passed to the processing means, which here takes the form of a personal computer, operable to convert the wavelength information obtained by the optical fibre grating interrogation apparatus 14 into the strain experienced by the FBG strain sensor 24, 26 being interrogated. The measured strain information is then used to ascertain the shape of the displacement translation member 22, as will be described in more detail below. Any change in the size and/or configuration of the crack 18 can then be determined.
The interstice displacement sensor 12 can detect a change in the size and/or configuration of the crack 18 due to movement of the crack within the plane of the crack (indicated by arrow A in Figures 1 and 2) and/or due to movement of the crack within a plane generally perpendicular to the plane of the crack (indicated by arrow B in Figures 1 and 3).
Figures 2a and 2b illustrate the change in the shape of the displacement translation member 22 caused by an increase in the width of the crack 18 i.e. a displacement within the plane of the crack. The initial shape of the displacement translation member 22 (at zero displacement) is shown in Figure 2a, where both ends of the displacement translation member 22 have the same radius of curvature R(0). Following the displacement within the plane of the crack, the shape of the displacement translation member 22 has changed to a broader, flatter shape, with the radii of curvature of the ends of the displacement translation member 22 changing by the same amount to a second, larger value R(1).
Figures 3a and 3b illustrate the change in the shape of the displacement translation member 22 caused by an increase in the height of the structural member 20 on one side (right hand side in the Figure) of the crack 18 i.e. a displacement in the plane perpendicular to the plane of the crack. The initial shape of the displacement translation member 22 (at zero displacement) is shown in Figure 3a, where both ends of the displacement translation member 22 have the same radius of curvature R(0). Following the perpendicular displacement of one side of the structural member 20, the shape of the displacement translation member 22 has changed to a less symmetrical shape, with the radii of curvature of each end of the displacement translation member 22 changing by different amounts. The radius of curvature of the first end of the displacement translation member 22 has decreased to R(2) and the radius of curvature of the other end of the displacement translation member 22 has increased to R(3).
When either perpendicular or in-plane movement of the crack occurs, the strain experienced by each FBG strain sensor 24, 26 changes as a result of a change in the axial and/or bend induced strain conditions existing within the displacement translation member 22 at each measurement location 22a, 22b. The change in strain experienced by the FBG strain sensors 24, 26 can be related to the perpendicular and/or in plane displacement of the crack as follows (assuming a symmetrical displacement translation member 22, as shown in Fig.1).
The strain c at the first measurement location 22a due to a displacement x in the plane of the crack (the x-direction) is given by 81x = kx where k is the strain modulus of the displacement translation member 22 in the xdirection, which is determined through calibration or numerical simulation of the crack sensor 10.
The strain 81y at the first measurement location 22a due to a displacement y perpendicular to the plane of the crack (the y-direction) is given by Ely = ky where k is the strain modulus of the displacement translation member 22 in the y- direction, which is determined through calibration or numerical simulation of the crack sensor 12.
The total strain at the first measurement location 22a is given by El = 81x + E1y kx + ky (Equation 1) The strain C2x at the second measurement location 22b due to a displacement x in the plane of the crack (the xdirection) is given by E2x = kx The strain 82y at the first measurement location 22b due to a displacement y perpendicular to the plane of the crack (the y-direction) is given by E2y = The total strain at the second measurement location 22b is given by 62 = 62x + 62y = kx - ky (Equation 2) Equations 1 and 2 can be solved to determine the displacement of the crack 18 in each of the in-plane (x) and perpendicular (y) directions, as follows: x = (El + E2)/2kx y = (61 - As the skilled person will appreciate, the strains experienced by the FBG strain sensors 24, 26 are dependent upon the distance of the strain sensors 24, 26 from the neutral axis of the displacement translation member 22 - the further the sensor 24, 26 from the neutral axis, the larger the strain experienced by the sensor 24, 26.
An interstice displacement sensor 40 according to a second embodiment of the invention is shown in Figure 4. The interstice displacement sensor 40 is substantially the same as the sensor 12 of the first embodiment, with the following modifications.
The same reference numbers are retained for corresponding features.
The interstice displacement sensor 40 of this embodiment additionally comprises a first bridging element 42 and a second bridging element 44 respectively provided between each end of the displacement translation member 22 and the respective fixing means 28, 30. Each bridging element 42, 44 comprises a strip of material having a high modulus of elasticity.
The bridging elements 42, 44 act to effectively reduce the width of the crack 18.
Because the displacement translation member 22 extends across an effective gap which is smaller than the actual width of the crack 18, any changes in the width of the crack 18 produce a correspondingly larger change in the width of the effective gap. As a result, small changes in the width of the crack 18 can be more accurately measured than if the displacement translation member 22 extended across the full width of the crack 18, as in the first embodiment.
An interstice displacement sensor 50 according to a third embodiment of the invention is shown in Figure 5. The interstice displacement sensor 50 is substantially the same as the sensor 12 of the first embodiment, with the following modifications. The same reference numbers are retained for corresponding features.
In this embodiment, the displacement translation member 22 has a more steeply curved shape than that of the first embodiment, with each end of the displacement translation member 22 having a larger radius of curvature, R(4). The larger radii of curvature results in a reduction in the magnitude of the strain transferred to the FBG strain sensors 24, 26. The displacement translation member 22 of this embodiment can therefore be used to measure larger displacements than the displacement translation member of Fig.1.
An interstice displacement sensor 60 according to a fourth embodiment of the invention is shown in Figure 6. The sensor 60 according to this embodiment is substantially the same as the sensor 12 of the first embodiment, with the following modifications.
The interstice displacement sensor 60 of this embodiment additionally comprises a secondary translation displacement member 62 arranged generally perpendicularly to the translation displacement member (which will now be referred to as the primary displacement translation member) 22 i.e. the secondary translation displacement member 62 lies within the plane of the crack 18 and the primary translation displacement member 22 lies within the plane perpendicular to the plane of the crack 18.
The secondary displacement translation member 62 is of the same size and configuration as the primary displacement translation member 22. The secondary displacement translation member 62 is provided with a third FBG strain sensor 64, provided at a first measurement location 62a, and a fourth FBG strain sensor 66, provided at a second measurement location 62b. Third and fourth fixing means 68, 70 are respectively provided at each end of the secondary displacement translation member 62, for fixing the secondary displacement translation member 62 to the structural member 20.
In this example, the interstice displacement sensor 60 additionally comprises a temperature sensor, in the form of an FBG temperature sensor 72, provided at one end of the primary displacement translation member 22. The FBG temperature sensor 72 is provided to measure the temperature at the interstice displacement sensor 60, thereby allowing the strain measurements made by the FBG strain sensors 24, 26, 64, 66 to be temperature compensated. The provision of an FBG temperature sensor for temperature compensating FBG strain sensors will be well known to the skilled person and so will not be described in detail here.
The FBG temperature sensor 72 and the four FBG strain sensors 24, 26, 64, 66 are provided within a single optical fibre 74, which extends along the primary displacement translation member 22 and the secondary displacement translation member 62. The optical fibre 74 is bonded to the upper surface of each of the primary displacement translation member 22 and the secondary displacement translation member 62. It will be appreciated that the optical fibre 74 may alternatively be bonded to the lower surface one or both displacement translation members 22, 62, or may be embedded within one or both displacement translation members 22, 62.
The interstice displacement sensor 60 of this embodiment is operable to measure displacement in three dimensions, as indicated by arrows A, B and C in Figure 6.
An interstice displacement sensor 80 according to fifth embodiment of the invention is shown in Figure 7. The sensor 80 of this embodiment is broadly the same as the sensor 12 of the first embodiment, with the following modifications.
In this embodiment, the displacement translation member 82 is formed into a corkscrew spring shape. Six FBG strain sensors 84, 86, 88, 90, 92, 94 are provided within an optical fibre 96, which is bonded to the external surface of the displacement translation member 82. The FBG strain sensors are arranged into a first set 84, 88, 92 and a second set 86, 90, 94, with the first set of sensors being located at a 90 degree rotation to the second set of sensors i.e. each sensor 84, 88, 92 in the first set is located at 3 o'clock and each sensor 86, 90, 94 is located at 12 o'clock.
Due to the arrangement of the FBG strain sensors 84, 86, 88, 90, 92, 94, the interstice displacement sensor 80 can differentiate between axial extension of the displacement translation member 82 and rotation of one or both ends of the displacement translation member 82. The interstice displacement sensor 80 of this embodiment can therefore be used to measure displacement in the plane of the interstice (indicated by arrow A) and/or rotation of the structural member at one or both ends of the displacement translation member 82 (indicated by arrow D).
Figure 8 shows an interstice displacement sensor 100 according to a sixth embodiment of the invention. The interstice displacement sensor 100 according to this embodiment is substantially the same as the interstice displacement sensor 12 according to the first embodiment, with the following modifications. The same reference numbers have been retained for corresponding features.
In this embodiment, the interstice displacement sensor 100 has only one FBG strain sensor 24, which detects bending strain within the displacement translation member 22.
The interstice displacement sensor 100 is operable to measure displacement in one dimension (indicated by arrow A), enabling changes in the width of the crack 18 to be monitored.
Various modifications may be made without departing from the scope of the invention.
For example, the displacement translation member may be of a different size and/or configuration to those described. The strain sensors may comprise a different type of strain sensor, including a different type of optical fibre strain sensor such as a fibre Bragg grating Fabry-Perot etalon. A different number of strain sensors may be used to that described and where the strain sensors are described as FBG strain sensors, they may have a different resonant wavelength or linewidth to those described, and may be provided within a different number of optical fibres.
Where the interstice is described as a crack it will be appreciated that the sensor and the sensing apparatus may be used on a different type of interstice, such as a join or gap between structural members. Where a change in the size and/or configuration of the crack is described as being due to an increase in the width of the crack it will be appreciated that the sensor can also detect changes due to a decrease in the width of the crack. Where a change in the configuration of the crack is described as being due to an increase in the height of the structural member on one side of the crack it will be appreciated that the height of the structural member on the other side of the crack may alternatively or additionally increase, and that the heights may alternatively decrease.
The described embodiments provide various advantages, as follows. The interstice displacement sensor and the interstice displacement sensing apparatus enable the movement and/or growth of a crack to be measured and monitored. The displacement translation member permits movement of an interstice in up to 3 dimensions, in up to 2 perpendicular planes, to be detected, by transferring movement of an interstice, such as a crack, into axial strain and/or bend induced strain within the displacement translation member. Where the displacement translation member is arranged perpendicularly to the plane of the crack, shear movement of the crack can be measured.
The size and shape of the or each displacement translation member, and the materials from which it is fabricated, can be selected in order to translate crack movement of a predicted magnitude into strain levels of appropriate magnitude for the strain sensors and interrogation system. The interstice displacement sensor can thereby be used to measure a wide range of interstice movements: from hand high accuracy measurement of relatively small movements to large displacements of up to several metres.

Claims (18)

  1. Claims 1. An interstice displacement sensor comprising: a displacement
    translation member of curved configuration, to be located across an interstice to be monitored; a first strain sensor coupled to the displacement translation member at a first measurement location, wherein, a change in the size or configuration of the interstice being monitored is related to a displacement of one or more structural elements defining the interstice, such displacement causing a change in the bend induced strain conditions existing within the displacement translation member at the measurement location, thereby changing the strain conditions experienced by the strain sensor.
  2. 2. A sensor as claimed in claim 1, wherein the sensor further comprises a second strain sensor coupled to the displacement translation member at a second measurement location, wherein a change in the size or configuration of the interstice being monitored is related to a displacement of one or more structural elements defining the interstice, such displacement causing a change in the axial strain and/or bend induced strain conditions existing within the displacement translation member at one or both measurement locations, thereby changing the strain conditions experienced by the or each respective strain sensor.
  3. 3. A sensor as claimed in claims I or 2, wherein the sensor additionally comprises a secondary displacement translation member of curved configuration, to be located across the interstice to be monitored, and third and fourth strain sensors respectively coupled to the secondary displacement translation member at first and second measurement locations, the secondary displacement translation member being arranged generally perpendicularly to the displacement translation member.
  4. 4. A sensor as claimed in any preceding claim, wherein the or each strain sensor comprises an optical fibre strain sensor.
  5. 5. A sensor as claimed in claim 4, wherein the or each optical fibre strain sensor comprises a fibre grating strain sensor, such as a fibre Bragg grating or a fibre Bragg grating Fabry-Perot etalon.
  6. 6. A sensor as claimed in any preceding claim, wherein the or each displacement translation member comprises a strip of a flexible material having a curved configuration.
  7. 7. A sensor as claimed in claim 6, wherein the or each displacement translation member comprises a generally n-shaped strip of a flexible material.
  8. 8. A sensor as claimed in claim 7, wherein the or each displacement translation member comprises a generally sine curve shaped strip of a flexible material.
  9. 9. A sensor as claimed in any of claims I to 6, wherein the or each displacement translation member comprises a generally corkscrew shaped strip of a flexible material, the strain sensors being provided at first and second spaced locations along the displacement translation member.
  10. 10. A sensor as claimed in any preceding claim, wherein the strain conditions within the displacement translation member at each measurement location are substantially uniform along the length of the respective grating.
  11. 11. A sensor as claimed in any preceding claim, wherein the interstice displacement sensor additionally comprises fixing means provided at each end of the or each displacement translation member, for fixing the or each displacement translation member at each end to the or each structural member defining the interstice.
  12. 12. A sensor as claimed in any preceding claim, wherein the interstice displacement sensor further comprises first and second bridging elements to be respectively provided at each end of the or each displacement translation member.
  13. 13. A sensor as claimed in claim 12, wherein each bridging element comprises a strip of material having a high modulus of elasticity.
  14. 14. A sensor as claimed in any preceding claim, wherein the interstice displacement sensor further comprises a temperature sensor provided on the or each displacement translation member.
  15. 15. A sensor as claimed in claim 14, wherein the temperature sensor is an optical fibre grating temperature sensor, such as a fibre Bragg grating or a fibre Bragg grating Fabry-Perot etalon.
  16. 16. Interstice displacement sensing apparatus comprising: an interstice displacement sensor according to the first aspect of the invention; strain sensor interrogation apparatus operable to interrogate the strain sensors; and processing means operable to determine a change in the size and/or configuration of an interstice being measured from measurement information received from the interrogation apparatus.
  17. 17. An interstice displacement sensor substantially as described above with reference to the accompanying drawings.
  18. 18. Interstice displacement sensing apparatus substantially as described above with reference to the accompanying drawings.
GB0427051A 2004-12-09 2004-12-09 Optical-fibre interstice displacement sensor Withdrawn GB2421075A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0427051A GB2421075A (en) 2004-12-09 2004-12-09 Optical-fibre interstice displacement sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0427051A GB2421075A (en) 2004-12-09 2004-12-09 Optical-fibre interstice displacement sensor

Publications (2)

Publication Number Publication Date
GB0427051D0 GB0427051D0 (en) 2005-01-12
GB2421075A true GB2421075A (en) 2006-06-14

Family

ID=34073479

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0427051A Withdrawn GB2421075A (en) 2004-12-09 2004-12-09 Optical-fibre interstice displacement sensor

Country Status (1)

Country Link
GB (1) GB2421075A (en)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008053036A1 (en) * 2006-11-02 2008-05-08 Siemens Aktiengesellschaft Arrangement for measuring torsion or torsion with deflection
WO2008101657A1 (en) * 2007-02-19 2008-08-28 Hottinger Baldwin Messtechnik Gmbh Optical strain gauge
ITFI20080223A1 (en) * 2008-11-17 2010-05-18 Stardax S R L DEVICE AND PROCEDURE FOR DETECTION OR GENERATION OF A BEND
CN101806584A (en) * 2010-04-20 2010-08-18 中国计量学院 Double-layer arched micro-strain sensor
GB2479263A (en) * 2010-03-31 2011-10-05 Gen Electric Monitoring relative displacement of end-winding components in an electric generator
US8234083B2 (en) 2008-09-22 2012-07-31 Vestas Wind Systems A/S Wind turbine rotor blade comprising an edge-wise bending insensitive strain sensor system
US8235326B2 (en) 2007-07-26 2012-08-07 Airbus Operations Limited Aircraft landing gear load sensor
US8310657B2 (en) 2008-03-31 2012-11-13 Vestas Wind Systems A/S Optical transmission strain sensor for wind turbines
US8348611B2 (en) 2008-07-01 2013-01-08 Vestas Wind Systems A/S Wind turbine having a sensor system for detecting deformation in a wind turbine rotor blade and corresponding method
FR2983954A1 (en) * 2011-12-13 2013-06-14 Renault Sa SPRING WITH INTEGRATED DEFORMATION SENSOR.
US8514409B2 (en) 2010-03-31 2013-08-20 General Electric Company System for monitoring a relative displacement of components
US8712703B2 (en) 2008-12-16 2014-04-29 Vestas Wind Systems A/S Turbulence sensor and blade condition sensor system
US8733164B2 (en) 2010-02-04 2014-05-27 Vestas Wind Systems A/S Wind turbine optical wind sensor
US8814514B2 (en) 2008-07-03 2014-08-26 Vestas Wind Systems A/S Embedded fibre optic sensor for wind turbine components
EP2842777A1 (en) * 2013-08-30 2015-03-04 PSS Consultancy & Equipment B.V. Optical fiber sensor for a vehicle suspension system
US9014863B2 (en) 2009-08-06 2015-04-21 Vestas Wind Systems A/S Rotor blade control based on detecting turbulence
CN104613860A (en) * 2015-01-26 2015-05-13 北京科技大学 Flexible wearable paper-based strain sensor and preparation method thereof
CN105806209A (en) * 2016-05-12 2016-07-27 北京科技大学 Cuttable and wearable stress sensor and preparation method thereof
DE102015115927A1 (en) * 2015-09-21 2017-04-06 fos4X GmbH Sensor patch and method of making a sensor patch
CN106767689A (en) * 2017-03-06 2017-05-31 沈阳建筑大学 A kind of wedge structure fiber grating dislocation meter
CN106767475A (en) * 2016-11-18 2017-05-31 北京航空航天大学 A kind of hole-edge crack diagnostic method that fiber grating spectral image analysis are pasted based on horizontal cloth
CN106840869A (en) * 2016-12-15 2017-06-13 北京航空航天大学 A kind of hole-edge crack diagnostic method for being based on fiber grating spectral image analysis under two kinds of cloth patch modes
DE102016225218A1 (en) * 2016-12-16 2018-06-21 Zf Friedrichshafen Ag Shock absorber or spring damper
US10401155B2 (en) 2017-05-12 2019-09-03 Saudi Arabian Oil Company Apparatus and method for smart material analysis
US10746534B2 (en) 2017-07-03 2020-08-18 Saudi Arabian Oil Company Smart coating device for storage tank monitoring and calibration
US10877192B2 (en) 2017-04-18 2020-12-29 Saudi Arabian Oil Company Method of fabricating smart photonic structures for material monitoring
WO2021227339A1 (en) * 2020-05-11 2021-11-18 浙江大学 Multi-scale flexible photosensitive mechanical pressure sensor
US20220120325A1 (en) * 2020-10-16 2022-04-21 Accenture Global Solutions Limited Springs with strain feedback

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113899303A (en) * 2021-11-11 2022-01-07 中国水利水电科学研究院 High-precision measuring device and method for dynamic displacement of structural microcracks
CN115096484A (en) * 2022-06-21 2022-09-23 唐山市神州科贸有限公司 Force measuring device and method for bridge stress monitoring
CN119984080A (en) * 2025-02-19 2025-05-13 大连理工大学 A three-dimensional crack meter based on fiber grating sensing technology

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5633494A (en) * 1991-07-31 1997-05-27 Danisch; Lee Fiber optic bending and positioning sensor with selected curved light emission surfaces
US20020088931A1 (en) * 2001-01-11 2002-07-11 Danisch Lee Allan Topological and motion measuring tool
US6727491B1 (en) * 1999-01-29 2004-04-27 Deutsche Telekom Ag Sensor and method for detecting changes in distance
US20040083808A1 (en) * 2002-11-06 2004-05-06 Rambow Frederick Henry Kreisler Apparatus and method for monitoring compaction

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5633494A (en) * 1991-07-31 1997-05-27 Danisch; Lee Fiber optic bending and positioning sensor with selected curved light emission surfaces
US6727491B1 (en) * 1999-01-29 2004-04-27 Deutsche Telekom Ag Sensor and method for detecting changes in distance
US20020088931A1 (en) * 2001-01-11 2002-07-11 Danisch Lee Allan Topological and motion measuring tool
US20040083808A1 (en) * 2002-11-06 2004-05-06 Rambow Frederick Henry Kreisler Apparatus and method for monitoring compaction

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008053036A1 (en) * 2006-11-02 2008-05-08 Siemens Aktiengesellschaft Arrangement for measuring torsion or torsion with deflection
WO2008101657A1 (en) * 2007-02-19 2008-08-28 Hottinger Baldwin Messtechnik Gmbh Optical strain gauge
US8327716B2 (en) 2007-02-19 2012-12-11 Hottinger Baldwin Messtechnik Gmbh Optical strain gauge
US8235326B2 (en) 2007-07-26 2012-08-07 Airbus Operations Limited Aircraft landing gear load sensor
US8310657B2 (en) 2008-03-31 2012-11-13 Vestas Wind Systems A/S Optical transmission strain sensor for wind turbines
US8348611B2 (en) 2008-07-01 2013-01-08 Vestas Wind Systems A/S Wind turbine having a sensor system for detecting deformation in a wind turbine rotor blade and corresponding method
US8814514B2 (en) 2008-07-03 2014-08-26 Vestas Wind Systems A/S Embedded fibre optic sensor for wind turbine components
US8234083B2 (en) 2008-09-22 2012-07-31 Vestas Wind Systems A/S Wind turbine rotor blade comprising an edge-wise bending insensitive strain sensor system
WO2010055496A1 (en) * 2008-11-17 2010-05-20 Stardax S.R.L. A device and method for detecting or generating a curvature
ITFI20080223A1 (en) * 2008-11-17 2010-05-18 Stardax S R L DEVICE AND PROCEDURE FOR DETECTION OR GENERATION OF A BEND
US8712703B2 (en) 2008-12-16 2014-04-29 Vestas Wind Systems A/S Turbulence sensor and blade condition sensor system
US9014863B2 (en) 2009-08-06 2015-04-21 Vestas Wind Systems A/S Rotor blade control based on detecting turbulence
US8733164B2 (en) 2010-02-04 2014-05-27 Vestas Wind Systems A/S Wind turbine optical wind sensor
GB2479263A (en) * 2010-03-31 2011-10-05 Gen Electric Monitoring relative displacement of end-winding components in an electric generator
US8514409B2 (en) 2010-03-31 2013-08-20 General Electric Company System for monitoring a relative displacement of components
US8379225B2 (en) 2010-03-31 2013-02-19 General Electric Company System for monitoring a relative displacement of components
GB2479263B (en) * 2010-03-31 2017-07-05 Gen Electric System for monitoring a relative displacement of components
CN101806584B (en) * 2010-04-20 2012-11-14 中国计量学院 Double-layer arched micro-strain sensor
CN101806584A (en) * 2010-04-20 2010-08-18 中国计量学院 Double-layer arched micro-strain sensor
WO2013087580A1 (en) * 2011-12-13 2013-06-20 Renault S.A.S. Spring having a built-in deformation sensor
FR2983954A1 (en) * 2011-12-13 2013-06-14 Renault Sa SPRING WITH INTEGRATED DEFORMATION SENSOR.
US9352629B2 (en) 2011-12-13 2016-05-31 Renault S.A.S. Spring having a built-in deformation sensor
WO2015028266A1 (en) * 2013-08-30 2015-03-05 Pss Consultancy & Equipment B.V. A vehicle and a vehicle suspension
EP2842777A1 (en) * 2013-08-30 2015-03-04 PSS Consultancy & Equipment B.V. Optical fiber sensor for a vehicle suspension system
CN104613860A (en) * 2015-01-26 2015-05-13 北京科技大学 Flexible wearable paper-based strain sensor and preparation method thereof
DE102015115927A1 (en) * 2015-09-21 2017-04-06 fos4X GmbH Sensor patch and method of making a sensor patch
US10684145B2 (en) 2015-09-21 2020-06-16 fos4X GmbH Sensor patch and method for producing a sensor patch
CN105806209A (en) * 2016-05-12 2016-07-27 北京科技大学 Cuttable and wearable stress sensor and preparation method thereof
CN106767475A (en) * 2016-11-18 2017-05-31 北京航空航天大学 A kind of hole-edge crack diagnostic method that fiber grating spectral image analysis are pasted based on horizontal cloth
CN106840869B (en) * 2016-12-15 2019-08-23 北京航空航天大学 A kind of hole-edge crack diagnostic method based on fiber grating spectral image analysis under two kinds of cloth patch modes
CN106840869A (en) * 2016-12-15 2017-06-13 北京航空航天大学 A kind of hole-edge crack diagnostic method for being based on fiber grating spectral image analysis under two kinds of cloth patch modes
DE102016225218A1 (en) * 2016-12-16 2018-06-21 Zf Friedrichshafen Ag Shock absorber or spring damper
CN106767689A (en) * 2017-03-06 2017-05-31 沈阳建筑大学 A kind of wedge structure fiber grating dislocation meter
US10877192B2 (en) 2017-04-18 2020-12-29 Saudi Arabian Oil Company Method of fabricating smart photonic structures for material monitoring
US10401155B2 (en) 2017-05-12 2019-09-03 Saudi Arabian Oil Company Apparatus and method for smart material analysis
US10895447B2 (en) 2017-05-12 2021-01-19 Saudi Arabian Oil Company Apparatus for smart material analysis
US10746534B2 (en) 2017-07-03 2020-08-18 Saudi Arabian Oil Company Smart coating device for storage tank monitoring and calibration
US11536561B2 (en) 2017-07-03 2022-12-27 Saudi Arabian Oil Company Smart coating device for storage tank monitoring and cailibration
WO2021227339A1 (en) * 2020-05-11 2021-11-18 浙江大学 Multi-scale flexible photosensitive mechanical pressure sensor
US20220120325A1 (en) * 2020-10-16 2022-04-21 Accenture Global Solutions Limited Springs with strain feedback
US11877937B2 (en) * 2020-10-16 2024-01-23 Accenture Global Solutions Limited Springs with strain feedback

Also Published As

Publication number Publication date
GB0427051D0 (en) 2005-01-12

Similar Documents

Publication Publication Date Title
GB2421075A (en) Optical-fibre interstice displacement sensor
Zhang et al. FBG-type sensor for simultaneous measurement of force (or displacement) and temperature based on bilateral cantilever beam
Wang et al. Optical fiber sensing technology for full-scale condition monitoring of pavement layers
US9109883B2 (en) High resolution large displacement/crack sensor
Liu et al. Fiber Bragg grating based displacement sensors: State of the art and trends
JP2000111319A (en) Optical fiber sensor
CN108519175A (en) The soil pressure measurement method of changeable fluid based on bragg grating
US10739169B2 (en) Flat profile optical fiber cable for distributed sensing applications
Zhang et al. Deflection distribution estimation of tied‐arch bridges using long‐gauge strain measurements
KR101220311B1 (en) Bending sensor apparatus
Jiang et al. Distinguishable circumferential inclined direction tilt sensor based on fiber Bragg grating with wide measuring range and high accuracy
Sun et al. Dynamic response measurement of offshore platform model by FBG sensors
CN107328369A (en) Fiber Bragg grating strain sensor
CN117073571B (en) Temperature self-compensating optical fiber strain sensor with hinge and stepped reducing grating combined
Sa’ad et al. A fiber Bragg grating-based inclinometer probe with enhanced sensitivity for a higher slope profiling resolution
Moerman et al. Measuring ground anchor forces of a quay wall with Bragg sensors
Guru Prasad et al. Fiber Bragg grating sensor package for submicron level displacement measurements
Shi et al. FBG displacement sensor with hyperbolic flexible hinge structure
Barino et al. Loading condition estimation using long-period fiber grating array
Saha et al. A comparative study of fiber Bragg grating based tilt sensors
CN112880578B (en) System and method suitable for monitoring dislocation of airport pavement seam structure
US20160341612A1 (en) Sensing cable with enhanced sensitivity
Ansari Structural health monitoring with fiber optic sensors
Rizk et al. Structural health monitoring of slab-column connections using FBG sensors
CN101608976A (en) Intelligently composite material pole tower health monitoring device

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)