Method for in-situ preparation of strain sensor for concrete and measurement system

Abstract

The present application relates to a method and a measurement system for in-situ preparation of a strain sensor for concrete, and relates to the field of strain sensor preparation technology, which includes designing strain gauge information based on preset monitoring requirements; determining an in-situ preparation method based on the strain gauge information and a preset concrete state; using the in-situ preparation method to prepare a strain gauge. An installation groove with the shape and size included in the strain gauge information is formed on the concrete surface, and the strain gauge is formed in the installation groove, and the strain gauge is adhered and fitted to the side wall of the installation groove. The present application has the effect that there is a stronger bonding strength between the strain sensor and the concrete, and the accuracy of strain gauge monitoring is improved.

Description

Technical Field

[0001] This application relates to the field of strain sensor preparation technology, and particularly to a method and measurement system for in-situ preparation of strain sensors in concrete. Background Art

[0002] The durability and mechanical properties of concrete directly affect the safety, stability, and long-term serviceability of concrete structures. Under the influence of factors such as long-term load-bearing, environmental erosion, and temperature changes, a series of durability and mechanical property problems such as cracks, corrosion, and fatigue will occur in concrete structures. These problems not only reduce the service life of the structure but also increase the costs of maintenance and repair. Therefore, effective strain monitoring of concrete structures to early identify the decline or damage of structural performance has become a key means to ensure structural safety and extend the service life.

[0003] In the field of concrete strain monitoring, the most commonly used method is to use resistance strain gauges. By collecting the strain changes of the sensor over a period of time, the strain of the structure is calculated. It has the advantages of high sensitivity and low cost, and is easy to realize multi-point synchronous monitoring of the structure. In practical engineering applications, due to reasons such as environmental adaptability and usage cost, resistance strain gauges are still the most widely used strain sensors.

[0004] There are the following problems in the prior art. Resistance strain gauges are usually pasted on the concrete surface by brushing multiple layers of colloid, and the colloid itself has a certain deformation effect, resulting in the deformation of the concrete not being fully transmitted to the strain gauge, leading to inaccurate detection and there is still room for improvement. Summary of the Invention

[0005] In order to improve the problem that the colloid itself has a certain deformation effect, resulting in the deformation of the concrete not being fully transmitted to the strain gauge, leading to inaccurate detection, this application provides a method and measurement system for in-situ preparation of strain sensors in concrete.

[0006] In the first aspect, this application provides a method for in-situ preparation of strain sensors in concrete, adopting the following technical solution:

[0007] The method for in-situ preparation of strain sensors in concrete includes:

[0008] Designing strain gauge information based on preset monitoring requirements;

[0009] Determining the in-situ preparation method based on the strain gauge information and the preset concrete state;

[0010] Preparing the strain gauge by the in-situ preparation method. An installation groove with the shape, size, and dimensions contained in the strain gauge information is formed on the concrete surface, and the strain gauge is formed in the installation groove, and the strain gauge is adhered and fitted to the side wall of the installation groove.

[0011] By adopting the above technical solution, by directly in-situ manufacturing strain gauges on the surface or inside of concrete, the contact area between the strain gauges and the concrete is made sufficiently large, the bonding strength between the strain sensors and the concrete is stronger, enabling the strain gauges to fully receive the deformation of the concrete and improving the accuracy of strain gauge monitoring.

[0012] Optionally, the strain gauge includes an insulating part and a conductive part. The insulating part covers the outside of the conductive part, and the insulating part fits with the circumferential side wall of the installation groove.

[0013] By adopting the above technical solution, through the combination of the insulating part and the conductive part, the strain gauge has certain mechanical properties while ensuring good electrical conductivity, is not easily affected by the external environment, and improves the adaptability of the strain gauge to the environment.

[0014] Optionally, the specific method of the in-situ preparation method includes:

[0015] Determining printing information based on the strain gauge information and the preset printed concrete information when the concrete is in a preset non-solidified state;

[0016] Performing 3D printing using a preset 3D printing nozzle based on the printing information to form concrete containing strain gauges embedded in the installation grooves.

[0017] By adopting the above technical solution, since the concrete is still in the curing process during printing and cures synchronously with the strain gauges, the interface bonding is more firm, improving the bonding efficiency of the strain gauges.

[0018] Optionally, the 3D printing nozzle includes an outer tube containing the material for making the insulating part and an inner tube containing the material for making the conductive part. The inner tube is disposed inside the outer tube. The inner tube is provided with an inner tube nozzle for ejecting the material for making the conductive part, and the outer tube is provided with an outer tube nozzle for ejecting the material for making the insulating part. The inner tube nozzle passes through the outer tube and extends outside the outer tube nozzle. One side of the inner tube far from the inner tube nozzle is fixedly connected with an input tube extending outside the outer tube, and the input tube is communicated with the inner tube.

[0019] By adopting the above technical solution, by designing a special 3D printing nozzle, an insulating glue is extruded on the outer layer and a conductive glue is extruded on the inner layer. In this way, in the non-solidified concrete, the prepared strain gauge has an insulating layer; the insulating part, the conductive part, and the concrete are cured synchronously, and excellent bonding can be achieved among them.

[0020] Optionally, the specific method of the in-situ preparation method further includes:

[0021] Determining the installation groove size based on the strain gauge information and the preset ready-made concrete information when the concrete is in a preset solidified state;

[0022] Determine the material removal device based on the strain gauge information, off-the-shelf concrete information, and preset material removal accuracy;

[0023] Control the material removal device to remove concrete material on the concrete surface to form an installation groove corresponding to the installation groove size;

[0024] Prepare a strain gauge in the installation groove.

[0025] Optionally, it further includes a specific method for preparing a strain gauge in the installation groove, and this method includes:

[0026] Coat the inner side wall of the installation groove with a material for making the insulating part to form a fitting layer. The insulating part includes a fitting layer that fits with the inner side wall of the installation groove and a covering layer that covers the installation groove;

[0027] Fill the side of the fitting layer away from the inner side wall of the installation groove with a material for making the conductive part to form the conductive part;

[0028] Continue to coat the side of the conductive part near the opening of the installation groove with a material for making the insulating part to form the covering layer, and the covering layer is connected to the fitting layer in the installation groove.

[0029] By adopting the above technical solution, by first forming the insulating layer to ensure absolute insulation between the conductive part and the concrete, then filling the conductive part, and finally coating the surface of the conductive part with the insulating layer to ensure that the conductive adhesive is completely insulated, and the insulating adhesive and the conductive adhesive are cured simultaneously to ensure the bonding performance and insulating performance between the two.

[0030] In a second aspect, the present application provides a measurement system, adopting the following technical solution:

[0031] A measurement system includes:

[0032] A first strain sensor made by using the method for in-situ preparing a strain sensor in concrete as described above;

[0033] An IoT module, connected to the strain gauge through a wire and connected to a power supply through a wire.

[0034] By adopting the above technical solution, by directly in-situ manufacturing a strain gauge on the surface or inside of the concrete, the contact area between the strain gauge and the concrete is sufficient, the bonding strength between the strain sensor and the concrete is stronger, the strain gauge completely receives the deformation of the concrete, and the accuracy of strain gauge monitoring is improved.

[0035] In a third aspect, the present application provides a measurement system, adopting the following technical solution:

[0036] A measurement system includes:

[0037] A second strain sensor, manufactured by using the method for in-situ preparing a strain sensor in concrete as described above;

[0038] A wireless chip, integrated in the concrete, and the wireless chip is connected to the second strain sensor;

[0039] A first radio frequency antenna, manufactured by using the method for in-situ preparing a strain sensor in concrete as described above, and the first radio frequency antenna is connected to the wireless chip;

[0040] A first wireless transmitting module, transmitting a wireless signal to the first radio frequency antenna;

[0041] A first wireless receiving module, receiving the processed wireless feedback data signal.

[0042] By adopting the above technical solution, by preparing a wireless antenna and through processing such as radio frequency transmission, power supply and data transmission of the entire monitoring system can be achieved, without being restricted by physical conditions such as wires, improving the flexibility and convenience of data transmission.

[0043] Fourthly, the present application provides a measurement system, adopting the following technical solution:

[0044] A measurement system, comprising:

[0045] A second radio frequency antenna, manufactured by using the method for in-situ preparing a strain sensor in concrete as described above;

[0046] A second wireless transmitting module, transmitting a wireless signal to the second radio frequency antenna;

[0047] A second wireless receiving module, receiving the processed wireless feedback data signal.

[0048] By adopting the above technical solution, by not using a data analysis wireless chip and directly sensing a wireless signal by using a radio frequency antenna, under different deformation conditions, the resistance of the coil is different and the feedback ability to the wireless signal is different. Therefore, the received wireless signal is different, and thus the deformation of the measured concrete can be analyzed, realizing the function of a strain gauge and saving costs.

[0049] Fifthly, the present application provides a measurement system, adopting the following technical solution:

[0050] A measurement system, comprising:

[0051] A third strain sensor, manufactured by using the method for in-situ preparing a strain sensor in concrete as described above;

[0052] A processor, arranged on one side of the third strain sensor and electrically connected to the third strain sensor;

[0053] An electrochromic layer, coated on the side of the third strain sensor away from the concrete and electrically connected to the third strain sensor, is configured to drive the display of colors representing different deformation states through a circuit.

[0054] A third wireless transmission module, which transmits wireless signals to the third strain sensor.

[0055] An image processing module, which takes pictures of the electrochromic layer and processes them to identify the degree of deformation.

[0056] By adopting the above technical solution, the change in resistance is presented as a color visible to the human eye, which facilitates quick manual identification. Then, combined with image processing technology, the degree of deformation is accurately identified, improving the convenience and accuracy of identification.

[0057] In summary, the present application includes at least the following beneficial technical effects:

[0058] 1. By directly in-situ fabricating strain gauges on the surface or inside of concrete, the contact area between the strain gauges and the concrete is sufficient, and the bonding strength between the strain sensors and the concrete is stronger, improving the accuracy of strain gauge monitoring.

[0059] 2. By fabricating a wireless antenna and through processing such as radio frequency transmission, power supply and data transmission of the entire monitoring system can be achieved, without being restricted by physical conditions such as wires, improving the flexibility and convenience of data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a schematic structural diagram of a measurement system in Embodiment 1 of the present application.

[0061] Figure 2 is a schematic cross-sectional view of concrete and strain gauges in Embodiment 1 of the present application.

[0062] Figure 3 is a flowchart of a method for in-situ fabricating strain sensors in concrete in Embodiment 1 of the present application.

[0063] Figure 4 is a flowchart of a specific method for in-situ fabricating in Embodiment 1 of the present application.

[0064] Figure 5 is a schematic structural diagram of a 3D printing nozzle in Embodiment 1 of the present application.

[0065] Figure 6 is a schematic diagram of the structure of concrete and the stacked ones embedded in the concrete in Embodiment 1 of the present application.

[0066] Figure 7 is a flowchart of a specific method for fabricating strain gauges in an installation groove in Embodiment 1 of the present application.

[0067] Figure 8 It is a schematic structural diagram of a measurement system in Embodiment 2 of the present application.

[0068] Figure 9 It is a schematic application diagram of the measurement system in Embodiment 2 of the present application.

[0069] Figure 10 It is a schematic structural diagram of a measurement system in Embodiment 3 of the present application.

[0070] Figure 11 It is a schematic structural diagram of a measurement system in Embodiment 4 of the present application.

[0071] Description of reference numerals: 1. First strain sensor; 11. Insulating part; 111. Bonding layer; 112. Covering layer; 12. Conductive part; 2. Internet of Things module; 3. First wireless sensing component; 31. Second strain sensor; 32. Wireless chip; 33. First radio frequency antenna; 4. First radio frequency scanning component; 41. First wireless transmitting module; 42. First wireless receiving module; 5. Second wireless sensing component; 51. Second radio frequency antenna; 6. Second radio frequency scanning component; 61. Second wireless transmitting module; 62. Second wireless receiving module; 7. Third wireless sensing component; 71. Third strain sensor; 72. Processor; 73. Electrochromic layer; 8. Third radio frequency scanning component; 81. Third wireless transmitting module; 82. Image processing module; 9. 3D printing nozzle; 91. Outer tube; 911. Outer tube nozzle; 912. Input tube; 92. Inner tube; 921. Inner tube nozzle. Detailed implementation manners

[0072] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the following further elaborates on the present application in conjunction with the appended Figures 1 - 11 drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0073] Embodiment 1 of the present application discloses a measurement system.

[0074] Embodiment 1

[0075] Referring to Figure 1 , a measurement system includes a first strain sensor 1 and an Internet of Things module 2. The first strain sensor 1 is embedded in the surface or inside of the concrete. One end of the Internet of Things module 2 is connected with a wire, and the wire is electrically connected to the first strain sensor 1 installed on the concrete, so that the information on the first strain sensor 1 can be transmitted to the Internet of Things module 2. The Internet of Things module 2 is also connected to a power source to realize real-time acquisition and uploading of strain data, thereby improving the real-time performance and accuracy of structural health monitoring.

[0076] Reference Figure 2 , the first strain sensor 1 is composed of strain gauges, and the strain gauges include an insulating part 11 and a conductive part 12. The insulating part 11 covers the outside of the conductive part 12, and the insulating part 11 fits against the circumferential side wall of the installation groove. For ease of understanding, the insulating part 11 includes a fitting layer 111 that fits against the inner side wall of the installation groove and a covering layer 112 that covers the installation groove. An installation groove is formed on the concrete surface, the strain gauges are formed in the installation groove, and the strain gauges are adhered to and fit against the side wall of the installation groove.

[0077] Here, the conductive part 12 uses a conductive material (such as epoxy resin glue doped with silver powder / copper powder) to improve the strength and sensitivity of the strain sensor. The insulating part 11 uses an insulating material (such as epoxy resin) as the base material of the conductive glue to improve the good compatibility between the raw material of the conductive glue and the cement-based material. And because the material itself has no fixed shape, it is applicable to each monitoring point.

[0078] Reference Figure 3 , among which, the first strain sensor 1 is prepared by using the method of in-situ preparation of strain sensors for concrete, and this method includes:

[0079] Step 100: Design strain gauge information based on preset monitoring requirements.

[0080] The monitoring requirements include the requirements for the capabilities of the strain gauges for monitoring concrete, including the size, hardness, environment, stress conditions in actual projects, as well as the monitoring purpose, monitoring range, area, etc. The strain gauge information is the information such as the size, position, orientation, accuracy, and range of the designed strain gauges. The design method is through artificial experience combined with computer-aided design. Specifically, first, the concrete structure is modeled, and according to the application scenario of the concrete structure in the project, the deformed part is simulated and calculated. Generally speaking, using structural simulation technology, the best position should be the stress concentration area of the concrete structure, and the shape should match the stress conditions to ensure that the strain gauges can accurately capture the deformation of the structure. Then, based on artificial experience, corresponding sensor size and other parameters are designed on this part. If the concrete surface is not flat enough, some adjustments may be needed according to the specific situation to ensure the accuracy of the strain gauges.

[0081] Step 101: Determine the in-situ preparation method based on the strain gauge information and the preset concrete state.

[0082] The state of the concrete refers to the current state of the concrete. The in-situ preparation method is the method for preparing the sensor, such as additive manufacturing (3D printing) or subtractive manufacturing (such as CNC milling). The materials are used to directly prepare the strain gauge in-situ on the surface or inside of the concrete structure according to the predetermined shape and size. Improving this step by using new materials and new technologies can ensure precise fit and excellent bonding performance between the strain gauge and the concrete, thereby improving the reliability and accuracy of monitoring.

[0083] Refer to Figure 4 , wherein the specific methods of the in-situ preparation method include:

[0084] Step 1011: Determine the printing information based on the strain gauge information and the preset printed concrete information when the state of the concrete is the preset non-solidified state.

[0085] The non-solidified state is the state where the concrete has not solidified. The printed concrete information includes information such as the size of the concrete to be printed. The printing information is the comprehensive printing sequence and printing position including the printed concrete information and the printing of the strain gauge, and can also be a program code input into the 3D printing nozzle 9.

[0086] Step 1012: Perform 3D printing based on the printing information using the preset 3D printing nozzle 9 to form concrete containing a strain gauge embedded in the installation groove.

[0087] Refer to Figure 5 , the 3D printing nozzle 9 includes an outer tube 91 containing the material for making the insulating part 11 and an inner tube 92 containing the material for making the conductive part 12. The inner tube 92 is installed inside the outer tube 91. One end of the inner tube 92 is provided with an inner tube nozzle 921 for ejecting the material for making the conductive part 12. One end of the outer tube 91 is provided with an outer tube nozzle 911 for ejecting the material for making the insulating part 11. The inner tube nozzle 921 passes through the outer tube 91 and extends outside the outer tube nozzle 911. One side of the inner tube 92 away from the inner tube nozzle 921 is fixedly connected with an input tube 912 extending outside the outer tube 91, and the input tube 912 is communicated with the inner tube 92.

[0088] With such a design, the 3D printing nozzle 9 extrudes insulating glue on the outer layer and conductive glue on the inner layer simultaneously. During the printing process, adjust and optimize the equipment parameters as needed to ensure the quality and accuracy of the insulating layer. Regularly check whether there are problems during the printing process and make timely adjustments to ensure the uniformity and integrity of the insulating layer.

[0089] When the printed strain gauge is such as Figure 6When the upper and lower layers are stacked, the bottom layer is printed first, and then the upper layer. That is, the bottom layer is printed by inserting the printing nozzle (needle) into the (unsolidified) concrete, moving it horizontally and squeezing out the conductive material. As the vertical needle moves horizontally, a crack is cut in the concrete, but since the concrete is not solidified and still has fluidity, the crack will heal. Then, lift the needle a distance, and extrude it while lifting it. In this way, conductive wires in the vertical direction are prepared. Then, move horizontally again in the same way, so that conductive wires in the horizontal direction can be prepared. These parallel conductive wires in the horizontal direction are connected by vertical conductive wires to form a whole.

[0090] In addition, if the strain gauges are staggered on the same layer due to their own layout, for example, before crossing, spray a layer of insulating glue, and then print the second layer of conductive wires. In this way, the upper and lower layers of conductive wires are insulated.

[0091] Since the surface of concrete may be uneven, during the process of the printing nozzle (usually a needle with a diameter of 1mm) extruding and arranging the material, the laser ranging method can be used to allow the nozzle to move up and down following the unevenness of the concrete surface, so as to ensure a more uniform layout of the material.

[0092] Step 1013: When the concrete state is a preset solidification state, determine the size of the installation groove based on the strain gauge information and the preset ready-made concrete information.

[0093] The solidification state is the state in which the concrete is already solidified. The ready-made concrete information is the information of the concrete on which the strain gauge is to be prepared on the solidified concrete. The installation groove size is the information of the size of the installation groove. The determination method is the method of converting the strain gauge information.

[0094] Step 1014: Determine the subtractive equipment based on the strain gauge information, the ready-made concrete information and the preset subtractive accuracy.

[0095] Subtractive accuracy is the accuracy required of the subtractive equipment. Generally speaking, the most critical criterion is the accuracy of the subtractive equipment, because it directly affects the accuracy of the strain gauge. According to the size and shape of the strain gauge, choose equipment with corresponding processing capabilities, such as laser engraving machines are suitable for preparing small strain gauges, while CNC milling machines are suitable for preparing larger strain gauges. These equipment can accurately remove concrete material to form the predetermined strain gauge shape.

[0096] Step 1015: Control the subtractive device to remove concrete material from the concrete surface to form an installation groove corresponding to the size of the installation groove.

[0097] The concrete treated by the drill bit / milling head has a very rough surface, and the conductive adhesive material used fully fills the rough interface, which greatly enhances the bonding performance between the concrete and the strain material. Since the surface of the concrete may be uneven, during the process of grooving with the drill bit / milling head, the drill bit / milling head can move up and down following the unevenness of the concrete surface by means of laser ranging, so as to ensure more uniform material arrangement.

[0098] Step 1015: Prepare a strain gauge in the installation groove.

[0099] Refer to Figure 7 , and it also includes the specific method of preparing a strain gauge in the installation groove. This method includes:

[0100] Step 10151: Coat the material for making the insulating part 11 on the inner side wall of the installation groove to form a bonding layer 111.

[0101] Before punching the installation groove, clean the target surface of the concrete structure and ensure the surface is flat. The bonding layer 111 is an insulating pure oxygen resin glue. It is necessary to ensure that the entire surface of the groove is covered.

[0102] Step 10152: Fill the material for making the conductive part 12 on the side of the bonding layer 111 away from the inner side wall of the installation groove to form the conductive part 12.

[0103] When filling the conductive part 12 into the groove, it is necessary to ensure complete filling and tight fitting with the insulating glue.

[0104] Step 10153: Continuously coat the material for making the insulating part 11 on the side of the conductive part 12 close to the opening of the installation groove to form a covering layer 112.

[0105] The covering layer 112 needs to cover the entire surface of the groove to ensure tight connection with the bonding layer 111 in the installation groove. After that, the insulating glue and the conductive glue are cured simultaneously to ensure the bonding performance and insulating performance between the two.

[0106] Step 102: Prepare a strain gauge by using the in-situ preparation method.

[0107] The strain gauge prepared by using the steps of the above Steps 1011 - 10153 has good adhesion performance and strain performance.

[0108] After the strain gauge is prepared, immediately install necessary monitoring components in the created space, including sensors, electronic circuits, IoT modules, etc. These components are responsible for capturing strain data and realizing real-time data transmission.

[0109] After the installation is completed, system tests are conducted to verify the functionality of the strain gauges and the accuracy of the entire monitoring system. If necessary, the system is adjusted to ensure optimal monitoring results. The monitoring effectiveness can be judged by analyzing and processing the actual monitoring data, such as statistical analysis and anomaly detection. When the monitoring effectiveness is not satisfactory, it can be evaluated based on the actual monitoring data and analysis results to determine specific adjustment measures. For example, if the monitoring coverage is not wide enough, the printing parameters, such as printing speed and layer spacing, can be considered for adjustment to increase the number and coverage of the strain gauges. If the monitoring accuracy is not high enough, materials can be tried to be replaced, such as choosing a more conductive material to improve the monitoring accuracy. At the same time, the monitoring effectiveness can also be improved by changing the design scheme, such as adjusting the shape and size of the strain gauges to adapt to different structural characteristics. Additionally, if the monitoring effectiveness is not good, subtractive manufacturing techniques can be considered to process the concrete manufactured by additive techniques to improve the bonding performance and monitoring effectiveness. This can be achieved by selecting a more suitable material, such as coating a layer of conductive adhesive material on the surface of the additively manufactured concrete and then using subtractive manufacturing techniques to precisely fabricate the strain gauges. In summary, different adjustment measures can be taken according to the actual situation to ensure optimal monitoring results.

[0110] Embodiment 2

[0111] Referring to Figure 8 , a measurement system includes a first wireless sensing component 3 and a first radio frequency scanning component 4. The first wireless sensing component 3 includes a second strain sensor 31, a wireless chip 32, and a first radio frequency antenna 33. The first radio frequency scanning component 4 includes a first wireless transmission module 41 and a first wireless reception module 42. The second strain sensor 31 is embedded in the surface or inside of the concrete. Here, the second strain sensor 31 can be made by the in-situ preparation method of the strain sensor in Embodiment 1. The wireless chip 32 is embedded in the concrete and integrated onto the concrete surface (or inside) through an automatic mechanism. The first radio frequency antenna 33 is embedded in the surface or inside of the concrete, and here it can be prepared using the same conductive adhesive material as the second strain sensor 31. The first radio frequency antenna 33 is connected to the wireless chip 32, and the wireless chip 32 is connected to the second strain sensor 31 to achieve wireless transmission. Both the first wireless transmission module 41 and the first wireless reception module 42 perform wireless passive power supply and data transmission with the first radio frequency antenna 33. In a certain embodiment, such as Figure 9As shown, the first wireless sensing component 3 can be installed on the surface of the segment on the inner wall of the tunnel, and the first radio frequency scanning component 4 can be installed on the train. When the train passes by, the first radio frequency scanning component 4 will send a radio frequency signal to the surface of the segment. After receiving the radio frequency signal, the first wireless sensing component 3 on the segment will collect the deformation information of the segment and transmit the collected data back to the first radio frequency scanning component 4 to achieve the immediate detection of the segment deformation.

[0112] Embodiment 3

[0113] Referring to Figure 10 , a measurement system includes a second wireless sensing component 5 and a second radio frequency scanning component 6. The second wireless sensing component 5 includes a second radio frequency antenna 51. The second radio frequency scanning component 6 includes a second wireless transmission module 61 and a second wireless reception module 62. The second radio frequency antenna 51 is embedded in or inside the surface of the concrete, and the same conductive adhesive material as that of the first strain sensor 1 and the second strain sensor 31 can be used here for preparation and formation. Both the second wireless transmission module 61 and the second wireless reception module 62 are wirelessly and passively powered and data-transmitted with the second radio frequency antenna 51. Compared with Embodiment 2, the biggest difference is that the processor 72 is not used, and only the coil is used. The coil directly senses the wireless signal (i.e., electromagnetic wave). Under different deformation conditions, the resistance of the coil is different, and the feedback ability to the wireless signal is different. Therefore, the received wireless signal is different, and then the deformation of the measured concrete can be analyzed.

[0114] Embodiment 4

[0115] Referring to Figure 11, A measurement system, comprising a third wireless sensing component 7 and a third radio frequency scanning component 8. The third wireless sensing component 7 includes a third strain sensor 71, a processor 72, and an electrochromic layer 73. The third radio frequency scanning component 8 includes a third wireless transmission module 81 and an image processing module 82. The third strain sensor 71 is embedded in the surface or inside of the concrete, and here the same conductive adhesive material as the first strain sensor 1 and the second strain sensor 31 can be used for preparation. The processor 72 is embedded in the concrete and, similar to the wireless chip 32, is integrated onto the concrete surface (or inside) through an automatic mechanism. The third wireless transmission module 81 is connected to the processor 72 to transmit detection signals. The electrochromic layer 73 is coated on the side of the third strain sensor 71 away from the concrete and is electrically connected to the third strain sensor 71 and the processor 72 to drive the display of colors representing different deformation states through a circuit. The electrochromic layer 73 is an electrochromic paint, for example: existing e-paper technology / electrochromic glass technology, so that the color can exist for a long time. The image processing module 82 takes pictures and processes the electrochromic layer 73 to identify the degree of deformation. The specific installation method is as follows: After the tunnel segment construction is completed, a large number of third wireless sensing components 7 are prepared on the inner wall. Then, the third strain sensor 71 is basically calibrated through radio frequency technology, and different deformation thresholds are set. Then, the third radio frequency scanning component 8 is installed on the train. When the train passes by, the third wireless transmission module 81 transmits a wireless signal to drive the third strain sensor 71 to perform deformation detection, and the data is processed by the processor 72. When the detection reaches the specified deformation threshold, the processor 72 passes the corresponding current into the electrochromic layer 73 connected to it, so that the electrochromic layer 73 displays different colors. At this time, it can be judged by the naked eye of a person, or the tunnel can be photographed by the image processing module 82 on the train, and then image processing technology is used for rapid processing and identification.

[0116] Those skilled in the art can clearly understand that for the convenience and conciseness of description, only the above division of each functional module is used as an example for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working processes of the above-described system, device, and unit can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0117] The above are all the preferred embodiments of this application. The protection scope of this application is not limited thereby. Any feature disclosed in this specification (including the abstract and drawings), unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example in a series of equivalent or similar features.

Claims

1. A method for in-situ preparing a strain sensor for concrete, characterized in that, Comprising: Designing strain gauge information based on preset monitoring requirements; Determining an in-situ preparation method based on the strain gauge information and a preset concrete state; Preparing a strain gauge using the in-situ preparation method, an installation groove having a shape and size included in the strain gauge information being formed on the concrete surface, the strain gauge being formed in the installation groove, and the strain gauge being adhered to and fitting with the side wall of the installation groove; Wherein, the specific method of the in-situ preparation method includes: Determining printing information based on the strain gauge information and preset printed concrete information when the concrete state is a preset non-solidified state; Performing 3D printing using a preset 3D printing nozzle (9) based on the printing information to form concrete including a strain gauge embedded in the installation groove; Determining the installation groove size based on the strain gauge information and preset ready-mixed concrete information when the concrete state is a preset solidified state; Determining a subtractive device based on the strain gauge information, the ready-mixed concrete information, and a preset subtractive accuracy; Controlling the subtractive device to remove concrete material on the concrete surface to form an installation groove corresponding to the installation groove size; Preparing a strain gauge in the installation groove; The strain gauge includes an insulating part (11) and a conductive part (12), the insulating part (11) covering the outside of the conductive part (12), and the insulating part (11) fitting with the circumferential side wall of the installation groove; The 3D printing nozzle (9) includes an outer tube (91) containing a material for making the insulating part (11) and an inner tube (92) containing a material for making the conductive part (12), the inner tube (92) being disposed inside the outer tube (91), the inner tube (92) being provided with an inner tube nozzle (921) for ejecting the material for making the conductive part (12), the outer tube (91) being provided with an outer tube nozzle (911) for ejecting the material for making the insulating part (11), the inner tube nozzle (921) passing through the outer tube (91) and extending outside the outer tube nozzle (911), and one side of the inner tube (92) away from the inner tube nozzle (921) being fixedly connected to an input tube (912) extending outside the outer tube (91), the input tube (912) being in communication with the inner tube (92); Also including the specific method of preparing a strain gauge in the installation groove, the method including: Coating a material for making the insulating part (11) on the inner side wall of the installation groove to form a fitting layer (111), the insulating part (11) including a fitting layer (111) fitting with the inner side wall of the installation groove and a covering layer (112) covering the installation groove; Filling a material for making the conductive part (12) inside the fitting layer (111) away from the inner side wall of the installation groove to form the conductive part (12); Continuing to coat a material for making the insulating part (11) on one side of the conductive part (12) close to the opening of the installation groove to form the covering layer (112), the covering layer (112) being connected to the fitting layer (111) in the installation groove.

2. A measurement system, characterized in that, Comprising: A first strain sensor (1), made by using the method for in-situ preparing a strain sensor in concrete as described in claim 1; An Internet of Things module (2), connected to the strain gauge through a wire and connected to a power supply through a wire.

3. A measurement system, characterized in that, Comprising: The second strain sensor (31), which is made by the method for in-situ preparing a strain sensor in concrete as described in claim 1; The wireless chip (32), which is integrated in the concrete, and the wireless chip (32) is connected to the second strain sensor (31); The first radio frequency antenna (33), which is made by the method for in-situ preparing a strain sensor in concrete as described in claim 1, and the first radio frequency antenna (33) is connected to the wireless chip (32); The first wireless transmission module (41), which transmits a wireless signal to the first radio frequency antenna (33); The first wireless receiving module (42), which receives the processed wireless feedback data signal.

4. A measurement system, characterized in that, Comprising: The second radio frequency antenna (51), which is made by the method for in-situ preparing a strain sensor in concrete as described in claim 1; The second wireless transmission module (61), which transmits a wireless signal to the second radio frequency antenna (51); The second wireless receiving module (62), which receives the processed wireless feedback data signal.

5. A measurement system, characterized in that, Comprising: The third strain sensor (71), which is made by the method for in-situ preparing a strain sensor in concrete as described in claim 1; The processor (72), which is arranged on one side of the third strain sensor (71) and is electrically connected to the third strain sensor (71); The electrochromic layer (73), which is coated on the side of the third strain sensor (71) away from the concrete and is electrically connected to the third strain sensor (71) to drive the display of colors representing different deformation states through a circuit; The third wireless transmission module (81), which transmits a wireless signal to the third strain sensor (71); The image processing module (82), which takes pictures of and processes the electrochromic layer (73) to identify the degree of deformation.

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