A dry splicing joint interface force transmission sensing unit, system and method

Abstract

The present invention belongs to the field of structural stress monitoring, and specifically relates to a dry-type splicing node interface force transmission sensing unit, system and method, wherein the interface force transmission sensing unit includes a substrate, a first distributed optical fiber and a second distributed optical fiber; one side of the substrate is a coupling surface; the first distributed optical fiber and the second distributed optical fiber are arranged in the substrate along the length direction of the substrate; a cavity is arranged on the substrate along the length direction, and the cavity surrounds the three sides of the second distributed optical fiber away from the coupling surface. The interface force transmission sensing unit provided by the present invention can monitor the superimposed strain of the strain caused by the normal contact stress of the interface to be monitored and the tangential strain caused by the bending moment through the first distributed optical fiber, and monitor the tangential strain caused by the bending moment on the interface to be monitored through the second distributed optical fiber. The strain results monitored by the two optical fibers are calculated to obtain the true normal and tangential contact stress distribution.

Description

Technical Field

[0001] The present invention belongs to the field of structural stress monitoring, and particularly relates to a dry splicing joint interface force transmission sensing unit, system and method. Background Art

[0002] Prefabricated assembled structures have developed rapidly due to their significant advantages in energy conservation and emission reduction, improving construction efficiency, etc. As a key technology in prefabricated assembled structures, accurate monitoring of the force transmission performance of dry splicing joints is crucial for ensuring the safety and functionality of structures. However, different from continuous cross-section members that transmit stress through bending, dry splicing joints rely on the contact of the joint interface to transmit stress. This contact transmission method results in complex stress distribution on each interface of the joint and is prone to stress concentration in the joint area.

[0003] Traditional stress gauges are large in volume and can only monitor the stress state of a single measuring point, unable to meet the requirements of multi-interface stress sensing of dry splicing joints. The emergence of distributed optical fiber sensing technology provides new possibilities for solving this problem. This technology uses optical fibers as sensors, which can continuously monitor temperature and strain along the entire length of the optical fiber, realizing multi-point and distributed real-time monitoring of the structure. Distributed optical fiber sensing technology has the advantages of small volume, strong anti-electromagnetic interference ability, corrosion resistance, flexible installation, etc., and is particularly suitable for multi-interface stress monitoring of complex structures such as dry splicing joints.

[0004] Currently, there are pressure sensors based on distributed optical fiber sensing technology, and the strain monitored by the pressure sensors cannot accurately reflect the true force transmission situation of the joint interface. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dry splicing joint interface force transmission sensing unit, system and method that can still feedback the true force transmission situation when bearing axial force and bending moment.

[0006] The present invention provides a dry splicing joint interface force transmission sensing unit, including a base material, a first distributed optical fiber and a second distributed optical fiber;

[0007] One side of the base material is a coupling surface for coupling with the interface to be monitored;

[0008] The first distributed optical fiber and the second distributed optical fiber are arranged in the base material along the length direction of the base material;

[0009] A cavity is provided along the length direction on the base material, and the cavity surrounds three sides of the second distributed optical fiber facing away from the coupling surface.

[0010] Furthermore, the first distributed optical fiber and the second distributed optical fiber are at the same distance from the coupling surface.

[0011] Furthermore, the cavity penetrates through both ends of the substrate in the length direction.

[0012] Furthermore, the cross-section of the cavity is in a "U" shape, the opening side of the "U" shape faces the coupling surface, and the second distributed optical fiber is arranged in the middle of the "U" shape.

[0013] Furthermore, the coupling surface is a serrated structure.

[0014] Furthermore, the first distributed optical fiber and the second distributed optical fiber are two segments of the same optical fiber.

[0015] The present invention also provides an interface force transmission sensing system, including the above dry splicing joint interface force transmission sensing unit;

[0016] The first distributed optical fiber and the second distributed optical fiber of the dry splicing joint interface force transmission sensing unit are both connected to a distributed optical fiber demodulator, and the distributed optical fiber demodulator is connected to a data processing device.

[0017] Furthermore, when two or more dry splicing joint interface force transmission sensing units are connected in series, the first distributed optical fiber and the second distributed optical fiber of two or more dry splicing joint interface force transmission sensing units are connected in series in sequence, and the first distributed optical fiber and the second distributed optical fiber of the end dry splicing joint interface force transmission sensing unit are connected to the distributed optical fiber demodulator;

[0018] When two or more groups of dry splicing joint interface force transmission sensing units are connected in parallel, the first distributed optical fiber and the second distributed optical fiber of the end dry splicing joint interface force transmission sensing unit in each group are respectively connected to the distributed optical fiber demodulator; or, the first distributed optical fiber and the second distributed optical fiber of the end dry splicing joint interface force transmission sensing unit in each group are connected end to end, and the first distributed optical fiber and the second distributed optical fiber at the terminal are connected to the distributed optical fiber demodulator.

[0019] The present invention also provides an interface force transmission sensing method, using the above interface force transmission sensing system;

[0020] S1, install all the dry splicing joint interface force transmission sensing units on the interface to be monitored;

[0021] S2, the distributed optical fiber demodulator collects the strain data of the first distributed optical fiber and the second distributed optical fiber in all the dry splicing joint interface force transmission sensing units;

[0022] S3, the data processing device calculates the obtained strain data through a stress calculation model to obtain the normal contact stress and tangential contact stress of each dry splicing joint interface force transmission sensing unit.

[0023] S4. Obtain the normal stress distribution of the interface to be monitored according to the spatial position relationship between each normal contact stress and the force transmission sensing unit of the dry splicing node interface, obtain the tangential stress distribution of the interface to be monitored according to the spatial position relationship between each tangential contact stress and the force transmission sensing unit of the dry splicing node interface, and obtain the contact state of the interface to be monitored according to the normal stress distribution and the tangential stress distribution.

[0024] Furthermore, the stress calculation model includes a normal contact stress calculation model and a tangential contact stress calculation model;

[0025] The normal contact stress calculation model is:

[0026] ;

[0027] In the formula, is the normal contact stress, is the first distributed optical fiber monitoring strain, is the second distributed optical fiber monitoring strain, E is the elastic modulus of the base material, is the Poisson's ratio of the base material;

[0028] The tangential contact stress calculation model is:

[0029] ;

[0030] In the formula, is the tangential contact stress.

[0031] The beneficial effect of the present invention is that the force transmission sensing unit of the dry splicing node interface provided by the present invention can, by arranging the first distributed optical fiber and the second distributed optical fiber in the base material and arranging cavities in the three-side direction of the second distributed optical fiber, monitor the superimposed strain caused by the normal contact stress of the interface to be monitored and the tangential strain caused by the bending moment through the first distributed optical fiber, and the second distributed optical fiber monitors the tangential strain caused by the monitoring bending moment on the interface to be monitored. By calculating the strain results monitored by the two optical fibers, the true normal contact stress can be obtained, and at the same time, the contact state and tangential stress of the interface to be monitored can be obtained.

[0032] In addition, the force transmission sensing units of the dry splicing node interfaces can be networked, and the contact states of each interface, the normal contact stress distribution of the interface, and the tangential stress distribution of the interface on a large-area interface to be monitored can be obtained in combination with the coordinate positions of multiple force transmission sensing units of the dry splicing node interfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Attached Figure 1 is a schematic structural diagram of the force transmission sensing unit of the dry splicing node interface in the present invention;

[0034] Appendix Figure 2 Figure 1 is the front view of the interface force transfer sensing unit of the dry splicing joint in the present invention;

[0035] Appendix Figure 3 Figure 2 is the schematic diagram of the networking layout structure of the interface force transfer sensing system in the present invention;

[0036] Appendix Figure 4 Figure 3 is the schematic diagram of the interface stress and strain of the interface to be monitored under the action of axial force in the present invention;

[0037] Appendix Figure 5 Figure 4 is the schematic diagram of the interface stress and strain of the interface to be monitored under the combined action of axial force and bending moment in the present invention;

[0038] Appendix Figure 6 Figure 5 is the schematic diagram of the complex stress distribution of the dry splicing joint interface in the present invention;

[0039] Appendix Figure 7 Figure 6 is the schematic diagram of the structure of the interface force transfer sensing system in the present invention;

[0040] Appendix Figure 8 Figure 7 is the schematic diagram of the flow of the interface force transfer sensing method in the present invention.

[0041] In the figures, 1 - interface force transfer sensing unit of dry splicing joint; 101 - base material; 1011 - coupling surface; 102 - first distributed optical fiber; 103 - second distributed optical fiber; 104 - cavity; 2 - distributed optical fiber demodulator; 3 - data processing device; 4 - interface to be monitored; 401 - first component; 402 - second component; 5 - transmission optical fiber; 6 - data transmission device; 7 - computer; 8 - mobile terminal. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0044] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0045] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] As shown in the Figure 1 - appended Figure 8 figures, the present invention provides a dry splicing joint interface force transmission sensing unit 1, including a base material 101, a first distributed optical fiber 102, and a second distributed optical fiber 103;

[0048] One side of the base material 101 is a coupling surface 1011, and the coupling surface 1011 is used to be coupled with the interface 4 to be monitored, so that the tangential stress of the interface 4 to be monitored can be transmitted to the base material 101;

[0049] The first distributed optical fiber 102 and the second distributed optical fiber 103 are arranged in the base material 101 along the length direction of the base material 101. Both the first distributed optical fiber 102 and the second distributed optical fiber 103 are used to monitor the strain condition in the base material 101. Among them, the first distributed optical fiber 102 is in close contact with the inner wall of the base material 101 and is used to monitor the tangential strain generated when the base material 101 is subjected to normal and tangential actions, and thus can feedback the superimposed tangential strain generated when the interface 4 to be monitored is subjected to normal and tangential actions;

[0050] A cavity 104 is provided along the length direction on the substrate 101. The cavity 104 surrounds three sides of the second distributed optical fiber 103 facing away from the coupling surface 1011. The cavity 104 is arranged in such a way that it can shield the strain caused by the normal action of the substrate 101 on the second distributed optical fiber 103, so that only the strain caused by the tangential action of the substrate 101 is transmitted to the second distributed optical fiber 103. When the second distributed optical fiber 103 monitors the substrate 101 under normal and tangential actions, the tangential strain generated after shielding the normal action can be fed back, and then the tangential strain generated when the interface 4 to be monitored is under normal and tangential actions can be fed back.

[0051] The dry splicing joint interface force transmission sensing unit 1 provided by the present invention arranges the first distributed optical fiber 102 and the second distributed optical fiber 103 in the substrate 101, and arranges the cavity 104 in three directions of the second distributed optical fiber 103. Furthermore, the superposition strain caused by the normal contact stress and the tangential strain caused by the bending moment on the interface 4 to be monitored can be monitored through the first distributed optical fiber 102, and the tangential strain caused by the monitoring bending moment on the interface 4 to be monitored can be monitored through the second distributed optical fiber 103. By calculating the strain results monitored by the two optical fibers, the true normal contact stress can be obtained, and at the same time, the contact state and tangential stress of the interface 4 to be monitored can be obtained.

[0052] In addition, the dry splicing joint interface force transmission sensing unit 1 can be networked, and the contact states of each interface, the distribution of interface normal contact stress, and the distribution of interface tangential stress on a large-area interface 4 to be monitored can be obtained by combining the coordinate positions of multiple dry splicing joint interface force transmission sensing units 1.

[0053] In one embodiment, the distances of the first distributed optical fiber 102 and the second distributed optical fiber 103 from the coupling surface 1011 are the same, so as to ensure that the tangential strain data caused by the bending moment on the interface 4 to be monitored received by the first distributed optical fiber 102 and the second distributed optical fiber 103 are the same, and thus ensure the accuracy of the monitoring.

[0054] In one embodiment, the cavity 104 penetrates through both ends of the substrate 101 in the length direction. With such a setting, the strain caused by the normal action of the entire length direction of the substrate 101 on the second distributed optical fiber 103 can be completely shielded, the shielding effect can be improved, and thus the accuracy of the tangential stress fed back by the second distributed optical fiber 103 can be ensured.

[0055] Exemplarily, the cross-section of the cavity 104 continuously surrounds the upper left and right three sides of the second distributed optical fiber 103 (the lower side is the side close to the coupling surface 1011), for example, a semi-circular arc shape. Any structure that can achieve the above is within the scope of the technical solutions protected by the embodiments of the invention. In one preferred embodiment, the cross-section of the cavity 104 is in a "U" shape, and the opening side of the "U" shape faces the coupling surface 1011. The second distributed optical fiber 103 is arranged in the middle of the "U" shape. Such an arrangement can reduce the influence of the cavity 104 structure on the tangential strain caused by the bending moment.

[0056] In one embodiment, the coupling surface 1011 is a serrated structure to enhance the friction between the base material 101 and the interface 4 to be monitored and improve the coupling effect. During specific installation, the coupling surface 1011 is bonded to the interface 4 to be monitored with glue. At this time, the serrated structure can improve the bonding effect of the glue. Taking the interface 4 to be monitored as a concrete material as an example, the serrated structure and the microporous structure of the concrete can greatly improve the bonding effect of the glue.

[0057] In one embodiment, the first distributed optical fiber 102 and the second distributed optical fiber 103 are two segments of the same optical fiber, which can simplify the connection difficulty with the distributed optical fiber demodulator 2. Of course, the first distributed optical fiber 102 and the second distributed optical fiber 103 can also use two independent optical fibers to simplify the installation.

[0058] In one embodiment, the length of the dry splicing node interface force transmission sensing unit 1 along the longitudinal directions of the first distributed optical fiber 102 and the second distributed optical fiber 103 can be adjusted according to the size of the interface 4 to be monitored, and the width of the dry splicing node interface force transmission sensing unit 1 is much smaller than the width of the interface 4 to be monitored to ensure the monitoring effect.

[0059] The present invention also provides an interface force transmission sensing system, including at least one of the above-mentioned dry splicing node interface force transmission sensing units 1.

[0060] Both the first distributed optical fiber 102 and the second distributed optical fiber 103 of the dry splicing node interface force transmission sensing unit 1 are connected to a distributed optical fiber demodulator 2. The distributed optical fiber demodulator 2 collects the strain data of the first distributed optical fiber 102 and the second distributed optical fiber 103 in the dry splicing node interface force transmission sensing unit 1. Preferably, the first distributed optical fiber 102 and the second distributed optical fiber 103 are connected to the distributed optical fiber demodulator 2 through transmission optical fibers 5. The distributed optical fiber demodulator 2 is connected to a data processing device 3. The data processing device 3 is used to calculate and process the strain data collected by the distributed optical fiber demodulator 2 to obtain the normal contact stress and tangential contact stress of the interface 4 to be monitored.

[0061] When networking and arranging the force transmission sensing units 1 at the dry splicing joint interfaces, the normal stress distribution, shear stress distribution, and contact state can be obtained according to the normal contact stress and shear contact stress of each force transmission sensing unit 1 at the dry splicing joint interface and their corresponding spatial distribution relationships.

[0062] In one embodiment, the interface force transmission sensing system further includes a data transmission device 6 communicatively connected to the data processing device 3, and the data transmission device 6 is communicatively connected to a computer 7 and / or a mobile terminal 8. Furthermore, the obtained data can be quickly and intuitively fed back to the user. The normal contact stress, shear contact stress, normal stress distribution, shear stress distribution, and contact state of the interface 4 to be monitored are displayed in the terminal display devices such as the computer 7 and / or the mobile terminal 8.

[0063] In one embodiment, when two or more dry splicing joint interface force transmission sensing units 1 are connected in series, the first distributed optical fibers 102 and the second distributed optical fibers 103 of two or more dry splicing joint interface force transmission sensing units 1 are connected in series in sequence, and the first distributed optical fiber 102 and the second distributed optical fiber 103 of the end dry splicing joint interface force transmission sensing unit 1 are connected to the distributed optical fiber demodulator 2;

[0064] When two or more groups of dry splicing joint interface force transmission sensing units 1 are connected in parallel, the first distributed optical fibers 102 and the second distributed optical fibers 103 of the end dry splicing joint interface force transmission sensing unit 1 in each group are respectively connected to the distributed optical fiber demodulator 2; or, the first distributed optical fibers 102 and the second distributed optical fibers 103 of the end dry splicing joint interface force transmission sensing unit 1 in each group are connected end to end, and the first distributed optical fiber 102 and the second distributed optical fiber 103 of the terminal are connected to the distributed optical fiber demodulator 2;

[0065] At this time, when multiple dry splicing joint interface force transmission sensing units 1 are connected in series and multiple groups are connected in parallel, a network monitoring of the interface 4 to be monitored is formed, forming a planar monitoring network covering the entire interface 4 to be monitored. At this time, the interface 4 to be monitored can be a special-shaped surface or multiple interconnected or independent cross-sections.

[0066] In one embodiment, the distributed optical fiber sensing technology used selects the optical frequency domain reflectometry technology, which can achieve a minimum spatial resolution of 0.68 mm, facilitating the monitoring of spatially continuous stress and strain.

[0067] The present invention also provides an interface force transmission sensing method, using the above-mentioned networked interface force transmission sensing system;

[0068] S1, install all the dry splicing joint interface force transmission sensing units 1 on the interface 4 to be monitored;

[0069] S2, the distributed optical fiber demodulator 2 collects the strain data of the first distributed optical fiber 102 and the second distributed optical fiber 103 in all the force transmission sensing units 1 of the dry splicing node interfaces;

[0070] S3, the data processing device 3 calculates the obtained strain data through the stress calculation model to obtain the normal contact stress and the tangential contact stress of each force transmission sensing unit 1 of the dry splicing node interface;

[0071] S4, according to the spatial position relationship between each normal contact stress and the corresponding force transmission sensing unit 1 of the dry splicing node interface, the normal stress distribution of the interface 4 to be monitored is obtained. According to the spatial position relationship between each tangential contact stress and the corresponding force transmission sensing unit 1 of the dry splicing node interface, the tangential stress distribution of the interface 4 to be monitored is obtained. According to the normal stress distribution and the tangential stress distribution, the contact state of the interface 4 to be monitored is obtained.

[0072] In one embodiment, the stress calculation model includes a normal contact stress calculation model and a tangential contact stress calculation model;

[0073] The normal contact stress calculation model is:

[0074] ;

[0075] In the formula, is the normal contact stress, is the strain monitored by the first distributed optical fiber, is the strain monitored by the second distributed optical fiber, E is the elastic modulus of the base material, is the Poisson's ratio of the base material;

[0076] Through this normal contact stress calculation model, the tangential strain caused by the bending moment in the strain monitored by the first distributed optical fiber 102 can be offset to obtain the normal contact stress;

[0077] The tangential contact stress calculation model is:

[0078] ;

[0079] In the formula, is the tangential contact stress.

[0080] In one embodiment, when forming a network monitoring, the distributed optical fiber demodulator 2 is used to collect the strain data of the first distributed optical fiber 102 and the second distributed optical fiber 103 in all the force transmission sensing units 1 of the dry splicing node interfaces;

[0081] The data processing device 3 acquires the strain data of all the force transfer sensing units 1 at the dry splicing node interfaces, calculates all the normal contact stresses and tangential contact stresses according to the normal contact stress calculation model and the tangential contact stress calculation model, and stores the stress distribution data as the normal contact stress distribution according to the spatial correspondence between the corresponding measuring points when all the force transfer sensing units 1 at the dry splicing node interfaces are installed and each point of the interface to be monitored 4. and the tangential stress distribution , and obtains the stress state of each interface.

[0082] In one embodiment, obtaining the contact state of the interface to be monitored 4 according to the normal stress distribution and the tangential stress distribution includes:

[0083] The contact state is judged by the normal contact stress distribution , a judgment threshold k is set, If the value is lower than the threshold k, it is judged that the upper and lower interfaces of the point of the interface to be monitored 4 are disengaged from contact, If the value is greater than the threshold k, it is judged that the upper and lower interfaces of the point of the interface to be monitored 4 are in contact and transmit the contact stress.

[0084] Exemplarily, for force transfer sensing monitoring of the dry splicing node interface as the interface to be monitored 4, the interface to be monitored 4 includes a first member 401 and a second member 402 that are dry spliced and fit together, and the fitting surface of the first member 401 and the second member 402 is the interface to be monitored 4. The specific steps are as follows:

[0085] S11, according to the design of the dry splicing node, determine the specific size of the interface to be monitored 4. Specifically, referring to the appendix Figure 6 , taking the interface to be monitored 4 as an example of five sequentially connected interfaces, referring to the appendix Figure 3 , arrange a number of force transfer sensing units 1 at the dry splicing node interfaces in a planar monitoring network with a spacing d, and cover all five interfaces with the monitoring network;

[0086] S12, install the force transfer sensing unit 1 at the dry splicing node interface in the groove reserved for the dry splicing node interface to be measured; and network the force transfer sensing units 1 at the dry splicing node interfaces according to the monitoring requirements to cover the interface to be measured;

[0087] S21: Use the distributed optical fiber demodulator 2 to acquire the strain data of the first distributed optical fiber 102 and the second distributed optical fiber 103 in all the force transfer sensing units 1 at the dry splicing node interfaces;

[0088] S31: The data processing device 3 calculates the obtained strain data through the stress calculation model to obtain the normal contact stress and the tangential contact stress of each force transfer sensing unit 1 at the dry splicing node interface;

[0089] S41: Obtain the normal stress distribution of the interface 4 to be monitored based on the spatial position relationship between each normal contact stress and the dry splicing joint interface force transmission sensing unit 1, obtain the tangential stress distribution of the interface 4 to be monitored based on the spatial position relationship between each tangential contact stress and the dry splicing joint interface force transmission sensing unit 1, and obtain the contact state of the interface 4 to be monitored based on the normal stress distribution and the tangential stress distribution;

[0090] S51: Transmit the data processed in S42 to the terminal display device (computer 7 or mobile terminal 8) through the data transmission device 6, and display the contact states of each interface of the dry splicing joint, the normal contact stress distribution of each interface of the node, and the tangential stress distribution of each interface of the node in the terminal display device;

[0091] Further, in step S11, it further includes: the height of the dry splicing joint interface force transmission sensing unit 1 is slightly higher than the depth of the groove reserved on the dry splicing joint interface to ensure that the stress on the interface after the dry splicing joint is assembled can be fully transmitted to the dry splicing joint interface force transmission sensing unit 1;

[0092] When installing the dry splicing joint interface force transmission sensing unit 1, apply a quick-drying glue on one side of the coupling surface 1011 of the base material 101 so that the dry splicing joint interface force transmission sensing unit 1 is fully coupled with the concrete material of the dry splicing joint;

[0093] Further, the normal contact stress in step S41 and the tangential stress After one-to-one correspondence with the interface spatial points, the output stress distribution data is stored as the normal contact stress distribution and the tangential stress distribution ;

[0094] Further, the contact state of each interface of the node in step S41 is judged by the normal contact stress distribution Set a judgment threshold k, If the value is lower than the threshold k, it is judged that the upper and lower interfaces of the dry splicing joint at this point are disengaged from contact, If the value is greater than the threshold k, it is judged that the upper and lower interfaces of the dry splicing joint at this point are in contact and transmit contact stress.

[0095] Further, in step S51, according to the contact judgment results of each point on the interface, the contact results can be displayed on the terminal display device, such as: the contact area is displayed in blue and the non-contact area is displayed in gray;

[0096] Further, in step S51, the interface contact state of the dry assembled joint is determined by the distribution of the contacted and non-contacted areas and the stress distribution. For example: State 1: Only one side area of the interface is a non-contacted area and the normal contact stress concentrates on the other side, and it can be determined that the interface opens on the side of the non-contacted area; State 2: Non-contacted areas are distributed on both adjacent sides of the interface and the normal contact stress distribution in the contacted area is uniform, and it can be determined that there is a step on the interface.

[0097] Further, in step S51, the magnitudes of the normal contact stresses of each interface of the joint and the tangential stresses of each interface of the joint can be displayed corresponding to different color scales for intuitive understanding of the interface stress state. Through the visualization interface, the monitoring personnel can intuitively observe the stress changes of the joint during the assembly process and whether there are any opening or stepping phenomena.

[0098] As described above, this is only an embodiment and does not impose any limitation on the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes, modifications or equivalents to equivalent embodiments by using the technical content disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A dry-type splicing node interface force transmission sensing unit, characterized in that it includes: A base material (101), a first distributed optical fiber (102) and a second distributed optical fiber (103); One side of the base material (101) is a coupling surface (1011), and the coupling surface (1011) is used to be coupled with the interface to be monitored (4); The first distributed optical fiber (102) and the second distributed optical fiber (103) are arranged in the base material (101) along the length direction of the base material (101); A cavity (104) is arranged on the base material (101) along the length direction, and the cavity (104) surrounds three sides of the second distributed optical fiber (103)背离 the coupling surface (1011); Collect the strain data of the first distributed optical fiber (102) and the second distributed optical fiber (103) in the dry splicing joint interface force transmission sensing unit (1), and calculate the obtained strain data through a stress calculation model to obtain the normal contact stress and tangential contact stress of the dry splicing joint interface force transmission sensing unit (1); The normal contact stress calculation model is: ； In the formula, is the normal contact stress, For the first distributed optical fiber strain monitoring, is the strain monitored by the second distributed optical fiber, E is the elastic modulus of the substrate, is the substrate Poisson’s ratio; The tangential contact stress calculation model is: ； In the formula, is the tangential contact stress.

2. The dry-type splicing node interface force transmission sensing unit according to claim 1 is characterized in that: The distances of the first distributed optical fiber (102) and the second distributed optical fiber (103) from the coupling surface (1011) are the same.

3. The dry-type splicing node interface force transmission sensing unit according to claim 1 is characterized in that: The cavity (104) penetrates through both ends of the base material (101) along the length direction.

4. The dry-type splicing node interface force transmission sensing unit according to claim 1 is characterized in that: The cross section of the cavity (104) is in a "U" shape; The opening side of the "U" shape faces the coupling surface (1011), and the second distributed optical fiber (103) is arranged in the middle of the "U" shape.

5. The dry-type splicing node interface force transmission sensing unit according to claim 1 is characterized in that: The coupling surface (1011) is a serrated structure.

6. The dry-type splicing node interface force transmission sensing unit according to claim 1, characterized in that: The first distributed optical fiber (102) and the second distributed optical fiber (103) are two segments of the same optical fiber.

7. An interface force transmission sensing system, characterized in that: It includes at least one dry splicing joint interface force transmission sensing unit (1) as described in any one of claims 1-6; Both the first distributed optical fiber (102) and the second distributed optical fiber (103) of the dry splicing joint interface force transmission sensing unit (1) are connected to a distributed optical fiber demodulator (2), and the distributed optical fiber demodulator (2) is connected to a data processing device (3).

8. The interface force transmission sensing system according to claim 7, characterized in that When two or more dry splicing joint interface force transmission sensing units (1) are arranged in series, the first distributed optical fiber (102) and the second distributed optical fiber (103) of two or more dry splicing joint interface force transmission sensing units (1) are connected in series in sequence, and the first distributed optical fiber (102) and the second distributed optical fiber (103) of the end dry splicing joint interface force transmission sensing unit (1) are connected to the distributed optical fiber demodulator (2); When two or more groups of dry-type splicing node interface force transmission sensing units (1) are arranged in parallel, the first distributed optical fiber (102) and the second distributed optical fiber (103) of the dry-type splicing node interface force transmission sensing units (1) at the end of each group are respectively connected to a distributed optical fiber demodulator (2); or, the first distributed optical fiber (102) and the second distributed optical fiber (103) of the dry-type splicing node interface force transmission sensing units (1) at the end of each group are connected end to end, and the first distributed optical fiber (102) and the second distributed optical fiber (103) at the terminal are connected to the distributed optical fiber demodulator (2).

9. A method for sensing interface force transmission, characterized in that: Using the interface force transmission sensing system as claimed in claim 8; S1, installing all dry-type splicing node interface force transmission sensing units (1) on the interface to be monitored (4); S2, the distributed optical fiber demodulator (2) collects strain data of the first distributed optical fiber (102) and the second distributed optical fiber (103) in all dry-type splicing node interface force transmission sensing units (1); S3, the data processing device (3) calculates the obtained strain data through a stress calculation model to obtain the normal contact stress and the tangential contact stress of each dry splicing node interface force transmission sensing unit (1); S4, obtaining the normal stress distribution of the interface to be monitored (4) according to the spatial position relationship between each normal contact stress and the corresponding dry splicing node interface force transmission sensing unit (1), obtaining the tangential stress distribution of the interface to be monitored (4) according to the spatial position relationship between each tangential contact stress and the corresponding dry splicing node interface force transmission sensing unit (1), and obtaining the contact state of the interface to be monitored (4) according to the normal stress distribution and the tangential stress distribution.

10. The interface force sensing method according to claim 9, characterized in that: The stress calculation model includes a normal contact stress calculation model and a tangential contact stress calculation model; The normal contact stress calculation model is: ； In the formula, is the normal contact stress, For the first distributed optical fiber strain monitoring, is the strain monitored by the second distributed optical fiber, E is the elastic modulus of the substrate, is the substrate Poisson’s ratio; The tangential contact stress calculation model is: ； In the formula, is the tangential contact stress.

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