A distributed optical fiber spatial strain testing device and testing method

Abstract

The present invention provides a distributed optical fiber spatial strain testing device and a testing method, belonging to the technical field of distributed optical fiber measurement. The device includes a test base; a loading mechanism installed on the test base for applying loads of different magnitudes to several nodes of the optical fiber in different directions; a coordinate measurement mechanism installed on the test base for measuring the coordinates of the nodes in three-dimensional space; and a strain measurement mechanism for measuring the strain data generated by the optical fiber after being loaded. The present invention applies loads of different magnitudes to several nodes of the optical fiber to be tested in different directions through the loading mechanism, so as to simulate different parts of the optical fiber being subjected to stresses of different directions and magnitudes, and collects the strain data of the optical fiber to be tested when it is subjected to stress through the strain measurement mechanism. Furthermore, the relationship between the stress direction of the optical fiber and the generated strain is explored based on the stress direction and magnitude, the generated strain magnitude, and the generated deformation of the optical fiber to be tested when it is subjected to stress.

Description

Technical Field

[0001] The present invention relates to the technical field of distributed optical fibers, and particularly to a distributed optical fiber spatial strain testing device and a testing method. Background Art

[0002] Distributed optical fiber sensing technology is a new type of sensing (strain, temperature) and transmitting external signals technology that has developed in recent years with the development of optical fiber communication technology. It has the advantages of full distribution, high precision, long service life, strong anti-interference ability, corrosion resistance, long-distance monitoring, etc. Especially for distributed optical fiber sensors, they are small in size, light in weight, convenient for laying and installation, and will not have a great impact on the performance and mechanical parameters of the monitored object when implanted.

[0003] In engineering practice, when the stress state of a structure changes, it will cause the structure to deform and displace. During this process, the strain data will also change accordingly. When the structure is subjected to forces from different directions and of different magnitudes, its strain has a clear directionality. However, the current application of distributed optical fiber sensing technology in structural monitoring mainly focuses on the acquisition of strain data, often ignoring the direction information in the strain data, while the actual displacement deformation of the structure is a three-dimensional variable, and its directionality is crucial.

[0004] Therefore, in order to determine and predict the displacement deformation of a structure by analyzing the distributed optical fiber strain monitoring data, it is necessary to incorporate the consideration of the directionality of strain in the data processing and analysis stage. This requires studying the strain direction information contained in the optical fiber sensing data under the action of stresses in different directions, so as to more comprehensively reflect the deformation characteristics of the structure. In this way, not only can the accuracy of the structural displacement deformation monitoring be improved, but also the reliability of the monitoring results can be enhanced, providing a more solid scientific basis for the safety assessment and maintenance of engineering structures.

[0005] In summary, how to test the influence of the stress direction on the optical fiber has become an urgent problem to be solved. Summary of the Invention

[0006] The present invention provides a distributed optical fiber spatial strain testing device and a testing method to solve the defect in the prior art that it is difficult to test the influence of the stress direction on the optical fiber strain, and to realize a distributed optical fiber spatial strain testing device for testing the influence of different stresses on the optical fiber strain.

[0007] The present invention provides a distributed optical fiber spatial strain testing device, including:

[0008] A test base;

[0009] A loading mechanism, installed on the test base, for applying loads of different magnitudes to several nodes of the optical fiber to be tested in different directions;

[0010] A coordinate measuring mechanism, installed on the test base, for measuring the coordinates of the node in three-dimensional space;

[0011] A strain measuring mechanism, for measuring the strain data generated by the optical fiber under test after being loaded.

[0012] According to a distributed optical fiber space strain testing device provided by the present invention, the loading mechanism includes a mounting base detachably fixed on the test base, a sliding rod vertically connected to the mounting base in a lifting manner, and a traction rope;

[0013] The traction rope is supported by the top end of the sliding rod, and one end of the traction rope is connected to the node, and the other end is provided with a load adjusting member.

[0014] According to a distributed optical fiber space strain testing device provided by the present invention, the loading mechanism further includes a pulley installed at the top end of the sliding rod, and the traction rope is wound around the pulley, and the gravity of the load adjusting member is converted into a loading force on the corresponding node through the pulley.

[0015] According to a distributed optical fiber space strain testing device provided by the present invention, the coordinate measuring mechanism includes a cross laser, a pose adjusting part for adjusting the pose of the cross laser, and a scale member arranged on the test base.

[0016] According to a distributed optical fiber space strain testing device provided by the present invention, the pose adjusting part includes a base for installing the cross laser, a height adjusting component arranged on the base, and an angle adjusting component connected to the height adjusting component;

[0017] The height adjusting component is used for adjusting the height of the cross laser in the vertical direction;

[0018] The angle adjusting component is used for adjusting the orientation of the output end of the cross laser in the vertical direction.

[0019] According to a distributed optical fiber space strain testing device provided by the present invention, the height adjusting component includes a support rod vertically fixed on the base, a sliding connecting member slidably connected along the axial direction of the support rod, the cross laser is installed on the sliding connecting member, and a first fixing member for fixing the sliding connecting member on the support rod is further arranged on the support rod.

[0020] According to a distributed optical fiber space strain testing device provided by the present invention, the angle adjusting component includes a rotating shaft rotatably connected to the sliding connecting member around its own axial direction, and the axial direction of the rotating shaft is perpendicular to the axial direction of the support rod;

[0021] It further includes a mounting member for mounting the cross laser on the rotating shaft and an angle adjusting member for adjusting the rotation angle of the rotating shaft.

[0022] In a distributed optical fiber spatial strain testing device provided by the present invention, a first spirit level for judging the mounting levelness of the cross laser is horizontally arranged on the rotating shaft.

[0023] In a distributed optical fiber spatial strain testing device provided by the present invention, a second spirit level for judging the mounting levelness of the cross laser is vertically arranged on the rotating shaft, and the second spirit level is perpendicular to the first spirit level.

[0024] The present invention also provides a distributed optical fiber spatial strain testing method, including:

[0025] Applying loads with different directions and magnitudes to several nodes of the optical fiber to be tested fixed on the test base through a loading mechanism;

[0026] Measuring the three-dimensional spatial coordinates of the nodes under the loads through a coordinate measuring mechanism;

[0027] Measuring the strain data generated by the nodes under the loads through the strain measuring mechanism;

[0028] Determining the relationship between the stress direction of the optical fiber to be tested and the generated strain according to the loads, the three-dimensional spatial coordinates and the strain data.

[0029] The distributed optical fiber spatial strain testing device and testing method provided by the present invention apply loads with different magnitudes in different directions to several nodes of the optical fiber to be tested through a loading mechanism, so as to simulate different parts of the optical fiber being subjected to stresses with different directions and magnitudes, and collect the strain data of the optical fiber to be tested when it is stressed through a strain measuring mechanism, and measure the deformation data of the optical fiber to be tested when it is stressed through a coordinate measuring mechanism. Furthermore, the relationship between the stress direction of the optical fiber to be tested and the generated strain is explored according to the stress direction and magnitude, the generated strain magnitude and the generated deformation of the optical fiber to be tested when it is stressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is the overall structural schematic diagram of the distributed optical fiber spatial strain testing device provided by the present invention;

[0032] Figure 2 It is a schematic structural diagram mainly used to show the test base in the distributed optical fiber spatial strain testing device provided by the present invention;

[0033] Figure 3 It is one of the schematic structural diagrams mainly used to show the loading mechanism in the distributed optical fiber spatial strain testing device provided by the present invention;

[0034] Figure 4 It is the second schematic structural diagram mainly used to show the loading mechanism in the distributed optical fiber spatial strain testing device provided by the present invention;

[0035] Figure 5 It is one of the schematic structural diagrams mainly used to show the coordinate measuring mechanism in the distributed optical fiber spatial strain testing device provided by the present invention;

[0036] Figure 6 It is the second schematic structural diagram mainly used to show the coordinate measuring mechanism in the distributed optical fiber spatial strain testing device provided by the present invention;

[0037] Figure 7 It is a schematic flow chart of the distributed optical fiber spatial strain testing method provided by the present invention;

[0038] Figure 8 It is a spatial coordinate diagram of the optical fiber constructed in the distributed optical fiber spatial strain testing method provided by the present invention under different loading states.

[0039] Reference numerals:

[0040] 1. Test base; 11. Bottom plate; 12. Back plate; 13. Side plate; 2. Coordinate measuring mechanism; 21. Cross laser; 22. Base; 23. Height adjusting assembly; 231. Support rod; 232. Sliding connecting member; 233. Second knob; 24. Angle adjusting assembly; 241. Rotating shaft; 242. Third knob; 243. Fourth knob; 25. Coordinate grid paper; 261. First bubble level; 262. Second bubble level; 3. Strain measuring mechanism; 31. Optical fiber access port; 4. Loading mechanism; 41. Mounting seat; 42. Rotating screw; 43. Mounting block; 44. Slide bar; 45. First knob; 46. Towing rope; 47. Weight; 48. Pulley; 51. First optical fiber clamp; 52. Second optical fiber clamp; 6. Optical fiber to be measured. Detailed implementation manners

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts belong to the scope of protection of the present invention.

[0042] The following will introduce a distributed optical fiber spatial strain measurement device of the present invention in conjunction with Figures 1 to 4 As shown in Figure 1 it includes:

[0043] A test base 1;

[0044] With reference to Figure 1 and Figure 2 , the test base 1 includes a rectangular bottom plate 11, two side plates 13 vertically fixed to both ends of the bottom plate 11 respectively, and a back plate 12 vertically fixed to one side of the bottom plate 11 in the length direction, thus forming an open box shape, which is used as an installation base for testing the optical fiber 6 to be measured.

[0045] Optionally, the fixed connection can be welding or a detachable fixed connection such as bolt connection.

[0046] A strain measurement mechanism 3 for measuring the strain data generated by the optical fiber 6 to be measured after being loaded.

[0047] The strain measurement mechanism 3 is used to measure the strain data generated by the optical fiber 6 to be measured after being stressed. Optionally, the strain measurement mechanism 3 can be an optical fiber strain analyzer. In this embodiment, an AQ8603 optical fiber strain analyzer is selected to measure the strain data of the optical fiber 6 to be measured after being stressed.

[0048] Specifically, on two opposite sides of the two side plates 13, a first optical fiber clamp 51 and a second optical fiber clamp 52 for clamping the optical fiber 6 to be measured are installed through positioning holes respectively.

[0049] The positioning holes are pre-opened at two opposite positions of the two side plates 13 for positioning and installing the first optical fiber clamp 51 and the second optical fiber clamp 52, so that after the first optical fiber clamp 51 and the second optical fiber clamp 52 are installed, the optical fiber 6 to be measured can be fixed in a direction parallel to both the bottom plate 11 and the back plate 12 at the same time.

[0050] In other feasible embodiments, multiple groups of positioning holes can also be opened at any opposite positions of the two side plates 13. The multiple groups of positioning holes can fix the optical fiber 6 to be measured at different positions of the test base 1, facilitating its measurement; they can also be used to fix multiple optical fibers 6 to be measured at the same time for testing.

[0051] One end of the optical fiber 6 to be measured is fixed to the first optical fiber fixture 51, and the other end is fixed by the second optical fiber fixture 52 and then connected to the optical fiber inlet 31 of the optical fiber strain analyzer. The optical fiber strain analyzer collects the strain data of the optical fiber 6 to be measured after applying a load to the optical fiber 6 to be measured.

[0052] It should be noted that after the optical fiber 6 to be measured is installed through the first optical fiber fixture 51 and the second optical fiber fixture 52, a certain length needs to be reserved at both ends. In this application, 2 meters are reserved at both ends.

[0053] The loading mechanism 4 is installed on the test base 1 and is used to apply loads of different magnitudes to several nodes of the optical fiber 6 to be measured in different directions;

[0054] The loading mechanism 4 is detachably installed on the test base 1, and the number of loading mechanisms 4 is the same as the number of nodes that need to be loaded.

[0055] In a feasible implementation manner, as Figure 1 shown, three nodes that need to be loaded are predetermined on the optical fiber 6 to be measured. Therefore, three loading mechanisms 4 are correspondingly installed on the test base 1 to apply loads to each node respectively to simulate the stress received by the optical fiber 6 to be measured.

[0056] Optionally, by changing the installation position of the loading mechanism 4 on the bottom plate 11, the direction of the load applied by the loading mechanism 4 to the node can be changed, so as to simulate the stress on the optical fiber 6 to be measured in different directions.

[0057] Optionally, by changing the load magnitude of the output end of the loading mechanism 4 on the node, the stress of different magnitudes received by the optical fiber 6 to be measured can be simulated.

[0058] Furthermore, by applying loads of different directions and magnitudes to different nodes of the optical fiber 6 to be measured, the state of different positions of the optical fiber 6 to be measured receiving different stresses of different directions and magnitudes is simulated, and the strain data of the optical fiber 6 to be measured in the corresponding state is measured by using the optical fiber strain analyzer, so as to explore the relationship between the stress direction of the optical fiber and the generated strain.

[0059] Optionally, the number and positions of the nodes on the optical fiber 6 to be measured are determined according to the test requirements.

[0060] The coordinate measuring mechanism 2 is installed on the test base 1 and is used to measure the coordinates of the nodes in three-dimensional space;

[0061] Since the optical fiber is not rigid, after the loading mechanism 4 applies a load to the node of the optical fiber 6 to be measured, the position of the node in three-dimensional space will also change.

[0062] The coordinate measuring mechanism 2 is used to measure the coordinates of the nodes in three-dimensional space before and after the nodes are loaded, so as to describe the position change of the nodes through the coordinates, and can characterize the deformation generated by the optical fiber 6 to be measured after being loaded through the position change of the nodes, so as to explore the relationship between the stress direction of the optical fiber and the generated strain in combination with the deformation of the optical fiber.

[0063] In the present invention, different loads are applied to several nodes of the optical fiber 6 to be measured in different directions by the loading mechanism 4, so as to simulate different parts of the optical fiber being stressed in different directions and magnitudes. The strain data when the optical fiber 6 to be measured is stressed is collected by the strain measuring mechanism 3, and the deformation data when the optical fiber 6 to be measured is stressed is measured by the coordinate measuring mechanism 2. Furthermore, the relationship between the stress direction of the optical fiber and the generated strain is explored based on the stress direction and magnitude, the generated strain magnitude, and the generated deformation when the optical fiber 6 to be measured is stressed.

[0064] In a distributed optical fiber spatial strain testing device of the present invention, the loading mechanism 4 includes a mounting seat 41 detachably fixed to the test base 1, a sliding rod 44 vertically connected to the mounting seat 41 in a lifting manner, and a towing rope 46;

[0065] The towing rope 46 is supported by the top end of the sliding rod 44, and one end of the towing rope 46 is connected to the node and the other end is provided with a load adjusting member.

[0066] As Figure 3 and Figure 4 As shown, the loading mechanism 4 includes a C-shaped mounting seat 41. One end of the mounting seat 41 is threadedly connected with a rotating screw 42. The axial direction of the rotating screw 42 is perpendicular to the end face of the C-shaped mounting seat 41, and one end of the rotating screw 42 extends into the C-shaped mounting seat 41. Driving the rotating screw 42 to rotate can make the rotating screw 42 move along its axial direction. A handle is installed at the lower end of the rotating screw 42, and a pressing plate is arranged at the upper end.

[0067] Specifically, after the C-shaped mounting seat 41 is clamped to the edge of the bottom plate 11 away from the back plate 12, rotating the handle in the positive direction drives the rotating screw 42 to rotate, which can drive the pressing plate on the rotating screw 42 to press against the side of the bottom plate 11 close to the ground and clamp the bottom plate 11 together with the other end of the C-shaped mounting seat 41, thus realizing the installation of the loading mechanism 4.

[0068] Driving the rotating screw 42 to rotate in the reverse direction can complete the disassembly of the mounting seat 41. Adjusting the position of the mounting seat 41 in the length direction of the bottom plate 11 can realize the position adjustment of the mounting seat 41 in the length direction of the bottom plate 11; by adjusting the depth of the C-shaped mounting seat 41 inserted into the bottom plate 11, the position adjustment of the mounting seat 41 in the width direction of the bottom plate 11 can be realized to fix the mounting seat 41 at other positions of the bottom plate 11, so as to apply loads to the nodes of the optical fiber 6 to be measured in different horizontal directions.

[0069] Further, a square mounting block 43 is fixedly connected to the side of the C-shaped mounting seat 41 away from the bottom plate 11. A sliding rod 44 is vertically connected to the mounting block 43. After the mounting seat 41 is fixed to the bottom plate 11, the axial direction of the sliding rod 44 is the vertical direction.

[0070] The sliding rod 44 can be a rod of different shapes such as a round rod or a square rod. The sliding rod 44 in this embodiment is a round rod.

[0071] The sliding rod 44 passes through the mounting block 43. At the same time, a first knob 45 for fixing the lifting position of the sliding rod 44 is provided on one side of the mounting block 43.

[0072] In a feasible implementation manner, the first knob 45 is threadedly connected to the mounting block 43, and the axial direction of the threaded section of the first knob 45 is perpendicular to the axial direction of the sliding rod 44. When the first knob 45 is screwed to move towards the mounting block 43, the end of the first knob 45 close to the mounting block 43 presses the sliding rod 44 against the mounting block 43 to fix the sliding rod 44; when the first knob 45 is screwed in the reverse direction to drive the first knob 45 to move away from the mounting block 43, the sliding rod 44 can move up and down in the mounting block 43, so as to adjust the height of the top end of the sliding rod 44.

[0073] In other feasible implementation manners, a right-angle transmission structure such as a pair of bevel gears can also be adopted. Through cooperation with the limiting structure, the sliding rod 44 can be driven to move in the vertical direction by screwing the first knob 45, so as to change the height of the top end of the sliding rod 44.

[0074] Further, the loading mechanism 4 further includes a traction rope 46. The traction rope 46 is an inelastic thin rope or thread. One end of the traction rope 46 is connected to the node of the optical fiber 6 to be measured. Optionally, one end of the traction rope 46 is directly tied to the node of the optical fiber 6 to be measured. The traction rope 46 can be removed and tied to other nodes to apply loads to nodes at different positions.

[0075] The traction rope 46 is supported by the top end of the sliding rod 44, and a load adjusting member is provided at the other end of the traction rope 46. On this basis, the load size of the node tied with the traction rope 46 can be adjusted by adjusting the load adjusting member; the stress direction of the node tied with the traction rope 46 on the horizontal plane can be adjusted by changing the installation position of the mounting seat 41 on the bottom plate 11; the stress direction of the node tied with the traction rope 46 on the vertical plane can be adjusted by adjusting the lifting of the sliding rod 44.

[0076] Optionally, a guiding arc groove is engraved at the top end of the sliding rod 44, so that the traction rope 46 is clamped in the guiding arc groove, thereby realizing the limitation of the traction rope 46 during the process of moving the mounting seat 41 and / or the lifting sliding rod 44, so as to avoid the traction rope 46 from detaching from the connection with the sliding rod 44 as much as possible.

[0077] In a feasible implementation manner, continue to refer to Figure 3 , the load adjusting member is a weight 47. One end of the traction rope 46 far away from the optical fiber 6 to be measured is tied to the weight 47, and by adjusting the quantity and / or weight of the weight 47, the magnitude of the load received by the node tied with the traction rope 46 can be adjusted.

[0078] In other feasible implementation manners, the load adjusting member can also be a linear driving mechanism. Connect one end of the traction rope 46 far away from the optical fiber 6 to be measured to the output end of the linear driving mechanism, and drive the output end of the linear driving mechanism to move in a direction away from the optical fiber 6 to be measured, then the traction rope 46 can be pulled, thereby applying a load to the node tied with the traction rope 46. Different moving distances of the output end of the linear driving mechanism correspond to different adjusted load magnitudes.

[0079] In addition, it should be noted that a scale is arranged along the axial direction on the outer arc surface of the sliding rod 44, which is used to read the lifting height of the sliding rod 44, and the change in the lifting height is converted into the angle between the first section of the traction rope 46 and the horizontal direction through trigonometric functions, which is used to mark the direction of the load received by the node during the test. Wherein, the first section of the traction rope 46 is the position where the traction rope 46 is tied to the optical fiber 6 to be measured to the connection between the traction rope 46 and the sliding rod 44.

[0080] In other feasible implementation manners, the direction of the load received by the node can also be marked by directly measuring the angle between the first section of the traction rope 46 and the horizontal direction.

[0081] In a distributed optical fiber spatial strain testing device of the present invention, the loading mechanism 4 further includes a pulley 48 installed at the top end of the sliding rod 44, and the traction rope 46 is wound around the pulley 48, and the gravity of the load adjusting member is converted into a loading force on the corresponding node through the pulley 48.

[0082] As Figure 4 shown, a pulley 48 is installed at the top end of the sliding rod 44, so that the traction rope 46 bypasses the guiding groove of the pulley 48, and the limitation and guiding of the traction rope 46 are realized through the pulley 48, thereby realizing the limitation of the traction rope 46 during the process of moving the mounting seat 41 and / or the lifting sliding rod 44, so as to avoid the traction rope 46 from detaching from the connection with the sliding rod 44 as much as possible, and the gravity of the load adjusting member is converted into a loading force on the corresponding node, thereby applying a load to the node.

[0083] Optionally, the pulley 48 can be detachably installed or connected to the top end of the slide bar 44 by means of rotational locking. Thus, when the connection line between the mounting base 41 and the corresponding node is not parallel to the width direction of the bottom plate 11, by changing the angle of the pulley 48, the projection direction of the first section of the traction rope 46 on the bottom plate 11 can be made parallel to the connection line direction between the mounting base 41 and the corresponding node.

[0084] In a distributed optical fiber spatial strain testing device of the present invention, the coordinate measuring mechanism 2 includes a cross laser 21, a pose adjusting part for adjusting the pose of the cross laser 21, and a scale member provided on the test base 1.

[0085] As Figure 2 shown, the coordinate measuring mechanism 2 includes a scale member provided on the test base 1.

[0086] In a feasible implementation manner, the scale member is a coordinate grid paper 25. By pasting the coordinate grid paper 25 on the bottom plate 11 and the back plate 12, the coordinates of any point on the bottom plate 11 or the back plate 12 can be determined through the coordinate grid.

[0087] In other feasible implementation manners, scales can also be directly engraved on the bottom plate 11 and the back plate 12.

[0088] Furthermore, as Figure 5 shown, the coordinate measuring mechanism 2 further includes a cross laser 21, and the cross laser 21 can emit cross-shaped laser light.

[0089] For any node of the optical fiber 6 to be measured, adjust the cross laser 21 to the same height as the node and emit cross laser light towards the node to the back plate 12. Then, the height of the node can be determined through the position of the cross laser light on the back plate 12.

[0090] Adjust the cross laser 21 above the node and emit cross laser light vertically towards the node to the bottom plate 11. Then, the coordinates of the node in the horizontal plane can be determined through the position of the cross laser light on the bottom plate 11.

[0091] Thus, the coordinates of the node in the three-dimensional space can be determined based on the coordinates of the node in the horizontal plane and the height of the node.

[0092] Therefore, the coordinate measuring mechanism 2 further includes a pose adjusting part for adjusting the height of the cross laser 21 and the emission angle of the output end.

[0093] In a distributed optical fiber spatial strain testing device of the present invention, the pose adjusting part includes a base 22 for mounting the cross laser 21, a height adjusting component 23 provided on the base 22, and an angle adjusting component 24 connected to the height adjusting component 23;

[0094] The height adjustment component 23 is used to adjust the height of the cross laser 21 in the vertical direction;

[0095] The angle adjustment component 24 is used to adjust the orientation of the output end of the cross laser 21 in the vertical direction.

[0096] The pose adjustment part includes a base 22, and a height adjustment component 23 and an angle adjustment component 24 are arranged on the base 22.

[0097] This application places no restrictions on the shape and material of the base 22. However, since the base 22 is placed on the bottom plate 11 movably to flexibly adjust the position of the cross laser 21 relative to the optical fiber 6 to be measured, the base 22 needs to stably support the cross laser 21, the height adjustment component 23, and the angle adjustment component 24.

[0098] Optionally, the height adjustment component 23 can be a linear drive member, and the cross laser 21 is arranged at the output end of the linear drive member. By adjusting the extension length of the output end of the linear drive member, the height of the cross laser 21 relative to the bottom plate 11 can be adjusted.

[0099] Optionally, the angle adjustment component 24 is connected to the height adjustment component 23, and the cross laser 21 is installed on the angle adjustment component 24. After the height of the cross laser 21 is adjusted, the emission angle of the cross laser is adjusted through the angle adjustment component 24.

[0100] In a distributed optical fiber spatial strain testing device of the present invention, the height adjustment component 23 includes a support rod 231 vertically fixed on the base 22. A sliding connection member 232 that slides along the axial direction of the support rod 231 is connected to the support rod 231. The cross laser 21 is installed on the sliding connection member 232. A first fixing member for fixing the sliding connection member 232 to the support rod 231 is further arranged on the support rod 231.

[0101] As Figure 5 shown, the height adjustment component 23 includes a support rod 231 vertically fixed on the base 22. The support rod 231 in this embodiment is a round rod.

[0102] A sliding connection member 232 that slides along the axial direction of the support rod 231 is connected to the support rod 231.

[0103] Optionally, the sliding connection between the sliding connection member 232 and the support rod 231 can be achieved by setting a slide rail and a slide groove.

[0104] Optionally, referring to Figure 5, the sliding connector 232 is an annular sleeve sleeved on the support rod 231. A second knob 233 is threadedly connected to the outer arc surface of the annular sleeve. The length direction of the threaded section of the second knob 233 is the radial direction of the annular sleeve. The angle adjustment assembly 24 is arranged at a position opposite to the second knob 233 on the outer arc surface of the annular sleeve.

[0105] Rotating the second knob 233 forward can drive the second knob 233 to move towards the support rod 231, pressing the annular sleeve against the support rod 231, thereby realizing the locking of the annular sleeve. Rotating the second knob 233 in the reverse direction can drive the second knob 233 to move away from the support rod 231, so that the annular sleeve can not only slide axially along the support rod 231, but also rotate radially around the support rod 231, so as to more flexibly adjust the height and the horizontal direction orientation of the cross laser 21, facilitating the cross laser 21 to emit cross laser towards the node.

[0106] In a distributed optical fiber spatial strain testing device of the present invention, the angle adjustment assembly 24 includes a rotating shaft 241 rotatably connected to the sliding connector 232 around its own axis, and the axis of the rotating shaft 241 is perpendicular to the axis of the support rod 231;

[0107] It further includes a mounting member for mounting the cross laser 21 on the rotating shaft 241 and an angle adjustment member for adjusting the rotation angle of the rotating shaft 241.

[0108] With reference to Figure 5 and Figure 6 , the angle adjustment assembly 24 is installed on one side of the sliding connector 232. Adjusting the height of the sliding connector 232 can synchronously adjust the height of the angle adjustment assembly 24.

[0109] Specifically, the angle adjustment assembly 24 includes a rotating shaft 241 rotatably connected to the sliding connector 232 around its axis, and the axis of the rotating shaft 241 is perpendicular to the axis of the support rod 231. The cross laser 21 is installed on the rotating shaft 241. Adjusting the rotation angle of the rotating shaft 241 can adjust the pitching angle of the output end of the cross laser 21.

[0110] In a feasible implementation manner, a hollow mounting sleeve is integrally formed in the middle of the rotating shaft 241, so that the rotating shaft 241 and the hollow mounting sleeve are integrally in a cross shape. The cylindrical cross laser 21 is inserted into the hollow mounting sleeve. A third knob 242 is threadedly connected to one end of the rotating shaft 241 away from the sliding connector 232, and the axial direction of the threaded section of the third knob 242 is perpendicular to the axial direction of the hollow mounting sleeve.

[0111] Thus, by turning the third knob 242 to move it towards the sliding connector 232, the cross laser 21 inserted into the hollow mounting sleeve can be pressed against the inner wall of the hollow mounting sleeve, completing the installation of the cross laser 21; by turning the third knob 242 to disengage it from the rotating shaft 241, the cross laser 21 can be removed from the rotating shaft 241 to adjust the installation position and / or installation angle of the cross laser 21.

[0112] After the cross laser 21 is installed, by rotating the rotating shaft 241, the pitching angle of the emission direction of the cross laser 21 can be adjusted. After the adjustment is completed, the rotating shaft 241 is fixed at the adjusted angle through the angle adjusting member, which is convenient for measuring the three-dimensional coordinates of the node by using the cross laser.

[0113] As Figure 5 and Figure 6 shown, in a feasible implementation manner, the angle adjusting member is the fourth knob 243. Specifically, the rotating shaft 241 is a hollow shaft, and a short column with the same axial direction as the rotating shaft 241 is fixedly connected to one side of the sliding connector 232, and the rotating shaft 241 is sleeved on the short column. The length direction of the threaded section of the fourth knob 243 is parallel to the radial direction of the rotating shaft 241, and the fourth knob 243 is threadedly inserted through the rotating shaft 241 and abuts against the short column. By turning the fourth knob 243 to drive it towards the short column, the rotating shaft 241 can be driven to abut against the short column, fixing the rotating shaft 241 at the adjusted angle; by reversely turning the fourth knob 243 to drive it away from the short column, the rotating shaft 241 can be rotated to adjust the angle of the cross laser 21 installed on the rotating shaft 241.

[0114] In summary, the pose adjustment of the position and angle of the cross laser 21 in the three-dimensional space can be realized, so that the coordinates of the node in the three-dimensional space can be marked by the cross laser 21.

[0115] In a distributed optical fiber space strain test device of the present invention, a first bubble level 261 for judging the installation levelness of the cross laser 21 is horizontally arranged on the rotating shaft 241.

[0116] Continuing to refer to Figure 6 , a first bubble level 261 is installed on the rotating shaft 241. The first bubble level 261 is arranged opposite to the cross laser 21, so that when the bubble of the first bubble level 261 is located at the center of its circular mark, that is, when the first bubble level 261 is in a horizontal state, the cross laser 21 is also in a horizontal state, that is, the horizontal laser in the cross laser emitted by the cross laser 21 is horizontal.

[0117] It should be noted that the first bubble level 261 can only roughly monitor the horizontal state of the cross laser 21. Therefore, when installing the cross laser 21 through the third knob 242 in this application, the installation angle of the cross laser 21 is determined by observing the bubble in the first bubble level 261, so as to roughly adjust the emission angle of the output end of the cross laser 21.

[0118] In a distributed optical fiber spatial strain testing device of the present invention, a second bubble level 262 for judging the installation levelness of the cross laser 21 is vertically arranged on the rotating shaft 241, and the second bubble level 262 is perpendicular to the first bubble level 261.

[0119] The second bubble level 262 is perpendicular to the first bubble level 261, and the second bubble level 262 is installed at one end of the first bubble level 261 far from the rotating shaft 241.

[0120] On this basis, by observing the first bubble level 261 and the second bubble level 262, when the bubbles of the two bubble levels are respectively located at the centers of their circular marks, it means that the horizontal laser and the vertical laser of the cross laser emitted by the cross laser 21 are respectively in the horizontal and vertical directions.

[0121] It still should be noted that when installing the cross laser 21 through the third knob 242, the installation angle of the cross laser 21 can be roughly adjusted by observing the positions of the bubbles in the first bubble level 261 and the second bubble level 262.

[0122] In actual use, through the angle adjusting component 24 and the height adjusting component 23, the center of the cross laser emitted by the cross laser 21 can be located at any grid point of the coordinate grid paper 25. At this time, by comparing whether the cross laser coincides with the grid lines, in the case of non - coincidence, loosen the third knob 242 and gradually adjust the position of the cross laser 21 until the cross laser it emits coincides with the grid lines, then tighten the cross laser 21 to achieve precise adjustment of its position, thereby completing the calibration of the cross laser 21. On this basis, the calibrated cross laser 21 is used to measure the three - dimensional space coordinates of the nodes.

[0123] Next, a distributed optical fiber spatial strain testing method provided by the present invention will be described. The distributed optical fiber spatial strain testing method described below can be mutually referred to with the distributed optical fiber spatial strain testing device described above.

[0124] As Figure 7 shown, a distributed optical fiber spatial strain testing method includes:

[0125] Step 701, applying loads with different directions and magnitudes to several nodes of the optical fiber 6 to be measured fixed on the test base 1 through the loading mechanism 4;

[0126] The loading mechanism 4 is movably installed on the test base 1, and the number of the loading mechanisms 4 is the same as the number of nodes to be loaded.

[0127] In a feasible implementation, as Figure 1 shown, there are three nodes to be loaded predetermined on the optical fiber 6 to be tested. Therefore, three loading mechanisms 4 are correspondingly installed on the test base 1 to apply loads to each node respectively to simulate the stress received by the optical fiber 6 to be tested.

[0128] Optionally, by changing the installation position of the loading mechanism 4 on the bottom plate 11, the direction of the load applied by the loading mechanism 4 to the node can be changed, so as to simulate the stress in different directions received by the optical fiber 6 to be tested.

[0129] Optionally, by changing the load magnitude of the output end of the loading mechanism 4 on the node, the stress in different magnitudes received by the optical fiber 6 to be tested can be simulated.

[0130] Furthermore, by applying loads with different directions and magnitudes to different nodes of the optical fiber 6 to be tested, the states of different positions of the optical fiber 6 to be tested receiving different stresses with different directions and magnitudes are simulated, and the strain data of the optical fiber 6 to be tested in the corresponding states are measured by using an optical fiber strain analyzer, so as to explore the relationship between the stress direction of the optical fiber and the generated strain.

[0131] Optionally, the number and positions of the nodes on the optical fiber 6 to be tested are determined according to the test requirements.

[0132] Step 702, measuring the three-dimensional space coordinates of the node under the load by the coordinate measuring mechanism 2;

[0133] Since the optical fiber is not rigid, after the load is applied to the node of the optical fiber 6 to be tested by the loading mechanism 4, the position of the node in the three-dimensional space will also change.

[0134] The coordinate measuring mechanism 2 is used to measure the coordinates of the node in the three-dimensional space before and after the node receives the load, so as to describe the position change of the node through the coordinates, and the deformation generated after the optical fiber 6 to be tested receives the load can be characterized by the position change of the node, so as to explore the relationship between the stress direction of the optical fiber and the generated strain in combination with the deformation of the optical fiber.

[0135] In a feasible implementation, three loading mechanisms 4 are used to apply loads to three nodes respectively. Among them, the load directions and magnitudes received by each node can be the same or different. At the same time, the three-dimensional space coordinates of these three nodes can be measured by using the coordinate measuring mechanism 2, or several additional nodes can be determined and their three-dimensional space coordinates can be measured, so as to more accurately explore the influence of stresses in different directions on the optical fiber through the coordinates of multiple nodes.

[0136] Step 703: Measure the strain data generated by the node under the load through the strain measurement mechanism 3.

[0137] The strain measurement mechanism 3 is used to measure the strain data generated after the fiber optic cable 6 to be measured is stressed. Optionally, the strain measurement mechanism 3 can be a fiber optic strain analyzer. In this embodiment, the AQ8603 fiber optic strain analyzer is selected to measure the strain data of the fiber optic cable after being stressed.

[0138] Specifically, on two opposite sides of the two side plates 13, a first fiber optic fixture 51 and a second fiber optic fixture 52 for clamping the fiber optic cable are installed through positioning holes respectively.

[0139] The positioning holes are pre-opened at two opposite positions of the two side plates 13 for positioning and installing the first fiber optic fixture 51 and the second fiber optic fixture 52, so that after the first fiber optic fixture 51 and the second fiber optic fixture 52 are installed, the fiber optic cable can be fixed in a direction parallel to both the bottom plate 11 and the back plate 12 at the same time.

[0140] One end of the fiber optic cable 6 to be measured is fixed to the first fiber optic fixture 51, and the other end is fixed by the second fiber optic fixture 52 and then connected to the interface of the fiber optic strain analyzer. After a load is applied to the fiber optic cable 6 to be measured, the fiber optic strain analyzer collects the strain data of the fiber optic cable 6 to be measured.

[0141] Step 704: Determine the relationship between the stress direction and the generated strain of the fiber optic cable 6 to be measured according to the load, the three-dimensional space coordinates, and the strain data.

[0142] According to the direction and magnitude of the load applied to the node of the fiber optic cable 6 to be measured, the three-dimensional space coordinates of the node of the fiber optic cable 6 to be measured after being loaded, and the strain data of the node of the fiber optic cable 6 to be measured after being loaded, explore the relationship between the stress direction and the generated strain of the fiber optic cable.

[0143] In a specific embodiment, as Figure 1 shown, from left to right in Figure 1 , the nodes are determined as Node 1, Node 2, and Node 3. Select Node 1 to hang a 200g weight 47, and the loading angles are -8°, 0°, and 8°. Measure the deformation positions of Node 1, Node 2, and Node 3 respectively, as well as the strain data of the fiber optic cable 6 to be measured obtained by the AQ8603.

[0144] As Figure 8As shown in the figure, based on the three-dimensional space coordinates of each node measured, a spatial coordinate map of the optical fiber 6 to be measured under different loading states is constructed, where the red color represents the spatial coordinates of the optical fiber 6 to be measured in the unloaded state, the black color represents the spatial coordinates of the optical fiber 6 to be measured when a load with an angle of -8° and a magnitude of 1.98 N is applied at node 1, the green color represents the spatial coordinates of the optical fiber 6 to be measured when a load with a horizontal angle and a magnitude of 1.98 N is applied at node 1, and the blue color represents the spatial coordinates of the optical fiber 6 to be measured when a load with an angle of 8° and a magnitude of 1.98 N is applied at node 1.

[0145] Based on the spatial coordinate map, the measured strain data, and the recorded load magnitude and direction, the relationship between the stress direction of the optical fiber and the generated strain can be explored.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A distributed optical fiber spatial strain testing device, characterized in that Including: Test base (1); A loading mechanism (4), mounted on the test base (1), for applying loads of different magnitudes to several nodes of the optical fiber under test (6) in different directions; A coordinate measuring mechanism (2), mounted on the test base (1), for measuring the coordinates of the nodes in three-dimensional space before and after the nodes are subjected to the load; A strain measuring mechanism (3), for measuring the strain data generated by the optical fiber under test (6) after being subjected to the load; Wherein, the loading mechanism (4) includes a mounting seat (41) detachably fixed to the test base (1), a sliding rod (44) vertically connected to the mounting seat (41), and a traction rope (46); The traction rope (46) is supported by the top of the sliding rod (44), and one end of the traction rope (46) is connected to the node, and the other end is provided with a load adjusting member; The test base (1) includes a bottom plate (11) and a back plate (12) vertically fixed to one side in the length direction of the bottom plate (11), and the coordinate measuring mechanism (2) includes a cross laser (21), a pose adjusting part for adjusting the pose of the cross laser (21), and scale members provided on the bottom plate (11) and the back plate (12).

2. The distributed optical fiber spatial strain testing device according to claim 1, wherein The loading mechanism (4) further includes a pulley (48) mounted on the top of the sliding rod (44), and the traction rope (46) is wound around the pulley (48), and the gravity of the load adjusting member is converted into a loading force on the corresponding node through the pulley (48).

3. The distributed optical fiber spatial strain testing device according to claim 1 or 2, characterized in that, The pose adjusting part includes a base (22) for mounting the cross laser (21), a height adjusting component (23) provided on the base (22), and an angle adjusting component (24) connected to the height adjusting component (23); The height adjusting component (23) is used to adjust the height of the cross laser (21) in the vertical direction; The angle adjusting component (24) is used to adjust the orientation of the output end of the cross laser (21) in the vertical direction.

4. A distributed optical fiber spatial strain testing device according to claim 3, characterized in that, The height adjusting component (23) includes a support rod (231) vertically fixed to the base (22), a sliding connecting member (232) slidably connected to the support rod (231) along its axial direction, the cross laser (21) is mounted on the sliding connecting member (232), and a first fixing member for fixing the sliding connecting member (232) to the support rod (231) is further provided on the support rod (231).

5. A distributed optical fiber spatial strain testing device according to claim 4, characterized in that, The angle adjusting component (24) includes a rotating shaft (241) rotatably connected to the sliding connecting member (232) around its own axis, and the axis of the rotating shaft (241) is perpendicular to the axis of the support rod (231); It further includes a mounting member for mounting the cross laser (21) on the rotating shaft (241) and an angle adjusting member for adjusting the rotation angle of the rotating shaft (241).

6. The distributed optical fiber spatial strain testing device according to claim 5, characterized in that, A first spirit level (261) for judging the horizontal installation level of the cross laser (21) is provided on the rotating shaft (241).

7. The distributed optical fiber spatial strain testing device according to claim 6, characterized in that, A second spirit level (262) for judging the installation levelness of the cross laser (21) is arranged on the rotating shaft (241), and the second spirit level (262) is perpendicular to the first spirit level (261).

8. A distributed optical fiber spatial strain measurement method, characterized in that When using the distributed optical fiber spatial strain testing device according to any one of claims 1-7, the method includes: applying loads with different directions and magnitudes to several nodes of the optical fiber to be tested (6) fixed to the test base (1) through a loading mechanism (4); measuring the coordinates of the nodes in a three-dimensional space before and after the nodes are subjected to the loads through a coordinate measuring mechanism (2); measuring the strain data generated by the nodes under the loads through the strain measuring mechanism (3); determining the relationship between the stress direction of the optical fiber to be tested (6) and the generated strain according to the loads, the three-dimensional space coordinates and the strain data.

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