A concrete internal structure condition monitoring device based on FRP fiber grating

Abstract

The invention discloses a concrete internal structure state monitoring device based on FRP fiber grating, comprising an FRP fiber grating strain gauge, an FRP fiber grating demodulator, a communication transmission module and an intelligent monitoring cloud platform. The FRP fiber grating strain gauge is pre-buried in a weak part of a structure to be monitored before concrete pouring, and is used to transmit measurement data inside the concrete structure to the FRP fiber grating demodulator; the FRP fiber grating demodulator is connected to the communication transmission module, and is used to demodulate the measurement data of the FRP fiber grating strain gauge so as to obtain strain data inside the concrete structure; the communication transmission module is connected to the FRP fiber grating demodulator or built in the FRP fiber grating demodulator, and is used to upload the strain data to the intelligent monitoring cloud platform; the intelligent monitoring cloud platform is connected to the FRP fiber grating demodulator through the communication transmission module, and is used to perform health assessment on the health state of concrete through the calculation of the cloud platform, so as to realize remote control and intelligent monitoring.

Description

Technical Field

[0001] The invention relates to the field of concrete structure health monitoring, and in particular to a concrete internal structure state monitoring device based on FRP optical fiber grating. Background Art

[0002] In today's society, concrete is an indispensable material for civil engineering construction. With the widespread application of concrete, the health of concrete structures has attracted much attention from the public. The irreversibility of concrete materials has also made experts and scholars pay special attention to the design safety of concrete structures. However, in large concrete structures, the complexity of the structure and cyclic loads will damage the stress concentration area of ​​the concrete structure, cause cracks in the concrete structure, and greatly affect the safety of the structure.

[0003] Concrete can generally be divided into load cracks and deformation cracks. Load cracks can be further divided into external load cracks and load secondary stress cracks; deformation cracks can also be divided into material deformation cracks and structural deformation cracks. Under the action of load, cracks that appear due to insufficient strength, rigidity or stability of the structure are called load cracks. This type of crack is mainly due to the low early tensile strength and elastic modulus of concrete, which causes structural deformation under the action of external loads, resulting in cracks. Cracks caused by temperature, shrinkage, uneven settlement, etc. are called deformation cracks.

[0004] At present, the healthy structure monitoring of concrete is mainly carried out by visual inspection, that is, observing the surface state of concrete to confirm the state of concrete; for large structures, most of them are modular concrete structures, with many internal concrete components and complex mechanical structures. There are no obvious scars on the outside due to internal structural damage; the existing monitoring methods cannot intuitively reflect the health status of concrete structures, and it is very necessary to monitor the health status of the internal structure of concrete. Summary of the invention

[0005] In order to overcome the deficiencies in the prior art, the present invention provides a concrete internal structure status monitoring device based on FRP fiber grating, which effectively avoids the drawbacks of the existing monitoring methods, combines the latest fiber grating sensing technology, arranges monitoring points in advance at the initial stage of concrete pouring, and monitors the structural health from the inside of the concrete structure without affecting the strength of the structure and the service status of the structure; the device uses optical signals and wireless networks to transmit data with extremely high accuracy, providing data support and protection for structural health and safety.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted to solve the technical problem is as follows:

[0007] A concrete internal structure condition monitoring device based on FRP fiber Bragg grating includes an FRP fiber Bragg grating strain gauge, an FRP fiber Bragg grating demodulator, a communication transmission module and an intelligent monitoring cloud platform, wherein:

[0008] The FRP fiber Bragg grating strain gauge is pre-buried in the weak part of the structure that needs to be monitored before the concrete is poured. One end is led out to the outside of the concrete structure through the fiber armored line, and the other end is connected to the FRP fiber Bragg grating demodulator through the fiber armored line to transmit the measurement signal inside the concrete structure to the FRP fiber Bragg grating demodulator.

[0009] The FRP fiber Bragg grating demodulator is connected to the communication transmission module and is used to demodulate the measurement signal of the FRP fiber Bragg grating strain gauge to obtain the strain data inside the concrete structure;

[0010] The communication transmission module is connected to the FRP fiber Bragg grating demodulator through a wire or is built into the FRP fiber Bragg grating demodulator, and is used to upload the strain data inside the concrete structure to the intelligent monitoring cloud platform;

[0011] The intelligent monitoring cloud platform is connected to the FRP fiber grating demodulator through the communication transmission module, and is used for:

[0012] Remotely control the working state of the FRP fiber grating demodulator through the communication transmission module;

[0013] Receive and store the real-time measurement data uploaded by the communication transmission module;

[0014] Combined with the initial selection of concrete structure grade and the real-time status of the concrete structure stress concentration area, the algorithm is converted and analyzed to display the internal structure strain value of the concrete and the corresponding safety level in real time;

[0015] Users can remotely log in to the intelligent monitoring cloud platform through a PC or APP to access cloud data and thus understand the safety and health status of the concrete structure in real time.

[0016] Furthermore, it also includes precast concrete blocks, the FRP fiber Bragg grating strain gauge is embedded in concrete aggregate with the same structure mix ratio, a model is made according to the characteristics of the concrete structure, and the model is processed into a precast concrete block, which is used to install the precast concrete block at a designated position during formal structure construction and lead out the wires to complete the pre-embedding of the FRP fiber Bragg grating strain gauge.

[0017] Furthermore, the intelligent monitoring cloud platform adopts a three-dimensional visualization module design, and the three-dimensional visualization monitoring module includes a refined 3D model display unit and a real-scene three-dimensional display unit, which are respectively used to realize the correlation and interaction of monitoring data and measuring points, thereby realizing three-dimensional dynamic visualization query and management of monitoring information of concrete structures during operation.

[0018] Furthermore, the FRP fiber Bragg grating demodulator includes a demodulator network interface, a demodulator power interface, a demodulator touch screen, a demodulator fiber Bragg grating interface and a rechargeable lithium battery, wherein:

[0019] The demodulator network interface is arranged on the side of the FRP fiber grating demodulator and is connected to the communication transmission module via a network cable;

[0020] The demodulator power interface is arranged on the side of the FRP fiber Bragg grating demodulator, and is connected to an external power source through a wire to charge a rechargeable lithium battery built into the FRP fiber Bragg grating demodulator;

[0021] The demodulator touch screen is arranged on the upper surface of the FRP fiber grating demodulator, and is used to intuitively display the internal structure state of the concrete. At the same time, the calculation formula can be edited to select the corresponding calculation formula for concrete structures of different strength grades, thereby ensuring high calculation accuracy;

[0022] The demodulator fiber Bragg grating interface is arranged on the side of the FRP fiber Bragg grating demodulator and is connected to the FRP fiber Bragg grating strain gauge through an optical fiber armored line.

[0023] Furthermore, the external power source is a solar power generation module, and the solar power generation module is connected to the FRP fiber Bragg grating demodulator by a power wire, which is used to power the rechargeable lithium battery of the FRP fiber Bragg grating demodulator under the condition of abundant outdoor sunlight.

[0024] Furthermore, the external power source is a wind power generation module, and the wind power generation module is connected to the FRP fiber Bragg grating demodulator by a power wire to provide clean energy for the FRP fiber Bragg grating demodulator in places such as tunnels where sunlight cannot reach.

[0025] Furthermore, the FRP fiber grating strain gauge includes an FRP fiber grating sensing point and an FRP fiber grating stress disk installed on the optical fiber inside the concrete structure. When the FRP fiber grating sensing point is squeezed or the FRP fiber grating stress disk is under stress, the corresponding strain value is displayed in real time on the touch screen of the demodulator.

[0026] Preferably, the FRP fiber Bragg grating strain gauge can fix multiple FRP fiber Bragg grating sensing points in one FRP fiber Bragg grating strain gauge for use in large concrete structures; or, multiple FRP fiber Bragg grating strain gauges can be connected in series and led out to the outside of the concrete structure with one wire.

[0027] Preferably, the communication transmission module is updated accordingly according to the signal base station in the project area, using 3G signals for network transmission in remote areas and 4G / 5G signals for network transmission in highly developed areas.

[0028] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0029] The present invention discloses a concrete internal structure status monitoring device based on FRP fiber grating. Before concrete pouring, the FRP fiber grating strain gauge is pre-buried in the weak part of the structure. The FRP fiber grating strain gauge can be customized according to the concrete structure. The signal is transmitted to the FRP fiber grating demodulator through the optical fiber armored line, and the data is uploaded to the intelligent monitoring cloud platform by the communication transmission device. Through the calculation of the platform system, the health status of the concrete is evaluated to realize remote control and intelligent monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0031] Figure 1 It is a structural schematic diagram of a concrete internal structure state monitoring device based on FRP fiber grating of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure of the FRP fiber Bragg grating strain gauge in the present invention;

[0033] Figure 3 It is a structural schematic diagram of the FRP fiber Bragg grating demodulator in the present invention;

[0034] Figure 4 It is an enlarged view of the combination of the FRP fiber Bragg grating strain gauge and the concrete structure in the present invention.

[0035]

Explanation of main symbols

[0036] 1-FRP fiber Bragg grating strain gauge;

[0037] 2-FRP fiber Bragg grating demodulator;

[0038] 3- Communication transmission module;

[0039] 4-Solar power generation module;

[0040] 5- Wind power generation module;

[0041] 6- Precast concrete blocks;

[0042] 7-FRP fiber Bragg grating sensing point;

[0043] 8-FRP fiber grating stress bearing disk;

[0044] 9- demodulator network interface;

[0045] 10- demodulator power interface;

[0046] 11-Touch screen display of demodulator;

[0047] 12-Fiber Bragg grating interface for demodulator. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] like Figure 1-4As shown, this embodiment discloses a concrete internal structure state monitoring device based on FRP fiber Bragg grating, including an FRP fiber Bragg grating strain gauge 1, an FRP fiber Bragg grating demodulator 2, a communication transmission module 3 and an intelligent monitoring cloud platform (not shown), wherein:

[0052] The FRP fiber Bragg grating strain gauge 1 is pre-buried in the weak part of the structure that needs to be monitored before the concrete is poured. One end is led out to the outside of the concrete structure through the fiber armored line, and the other end is connected to the FRP fiber Bragg grating demodulator 2 through the fiber armored line, which is used to transmit the measurement signal inside the concrete structure to the FRP fiber Bragg grating demodulator 2. In this embodiment, the principle of the FRP fiber Bragg grating strain gauge 1 is that the fiber Bragg grating utilizes the photosensitive properties of the optical fiber material, and irradiates the optical fiber with a laser of a specific wavelength in a specific way, causing the refractive index inside the optical fiber to change permanently along the axial direction, forming a periodic or non-periodic spatial phase distribution, thereby forming a grating structure, which is essentially a narrowband filter or reflector formed in the fiber core, and can accurately control the resonant wavelength. By controlling the FRP fiber Bragg grating material and converting and calculating the resonant wavelength, the corresponding strain of the sensor is obtained. The FRP fiber Bragg grating strain gauge 1 is a data acquisition device that integrates the acquisition, display, and storage of optical fiber sensor wavelength and power spectrum data, and has the characteristics of high precision, high resolution, and wide range of applicability. In actual operation, when pouring large-scale concrete, direct falling impact on the FRP fiber grating strain gauge 1 should be avoided, and the concrete should be poured around and vibrated.

[0053] The FRP fiber grating demodulator 2 is connected to the communication transmission module 3, and is used to demodulate the measurement signal of the FRP fiber grating strain gauge 1 to obtain the strain data inside the concrete structure. In this embodiment, the FRP fiber grating demodulator 2 demodulates the measurement signal of the fiber grating strain gauge, and its working principle is to read and transform the return values ​​of different center wavelengths of the fiber grating, and then obtain the change amount of external information. There are multiple FRP sensors with different reflection center wavelengths in the sensing optical fiber. Due to the effect of the Bragg condition, the wavelengths that meet the conditions of the FRP sensors with different reflection center wavelengths are reflected, and the light of the wavelengths that do not meet the conditions is transmitted. At this time, the external parameters are modulated into the reflection wavelength and enter the FRP fiber grating demodulator 2 through the coupler for demodulation.

[0054] The communication transmission module 3 is connected to the FRP fiber Bragg grating demodulator 2 or built into the FRP fiber Bragg grating demodulator 2 through a wire, and can be selected according to the actual needs of the project, and is used to upload the strain data inside the concrete structure to the intelligent monitoring cloud platform through network signal transmission via a built-in SIM card;

[0055] The intelligent monitoring cloud platform is a cloud platform based on the Internet of Things, which mainly integrates the functions of terminal equipment data collection, transmission, storage, analysis, safety assessment and early warning, manual inspection, reporting, etc., and is connected to the FRP fiber Bragg grating demodulator 2 through the communication transmission module 3, and is used for:

[0056] The working state of the FRP fiber Bragg grating demodulator 2 can be remotely controlled by the communication transmission module 3, and the FRP fiber Bragg grating demodulator 2 can be input with commands such as monitoring, standby, shutdown, and restart according to the project situation. In this embodiment, the working state of the FRP fiber Bragg grating demodulator 2 can be set to multiple working states such as standby, acquisition, timed acquisition, shutdown, and timed shutdown, which saves energy and extends the working time of the demodulator in special environments.

[0057] Receive and store the real-time measurement data uploaded by the communication transmission module 3;

[0058] Combined with the initial selection of the concrete structure grade and the real-time status of the concrete structure stress concentration zone, the algorithm conversion and analysis are used to display the internal structure strain value of the concrete and the corresponding safety level in real time. Specifically, the safety level classification standard of the intelligent monitoring cloud platform is divided according to the initial concrete strength grade, calculated according to the elastic and plastic standard values ​​corresponding to the concrete strength grade, and the actual value is used to refer to the standard value. The analysis algorithm is written in a calculation method that combines multiple methods such as the sudden rebound of strain when concrete is destroyed and the actual measurement value corresponding to the maximum cracking value. The cloud platform analyzes the actual data and obtains the internal safety and health status of the concrete.

[0059] Real-time, graded, and multi-mode early warning and monitoring report information release of concrete structure monitoring information provides scientific data basis for safe operation and maintenance of the structure;

[0060] The user can remotely log in to the intelligent monitoring cloud platform through a PC or APP to access the cloud data and thus grasp the safety and health status of the concrete structure in real time. In this embodiment, the concrete mix ratio in which the FRP fiber grating strain gauge 1 is actually buried is input into the intelligent monitoring cloud platform, and the intelligent monitoring cloud platform automatically starts real-time monitoring. During the monitoring process, the user can change the status of the monitoring device through the intelligent monitoring cloud platform, such as the interval between data collection, the collection or standby status of the collection device, etc. When the concrete structure reaches the warning value, the intelligent monitoring cloud platform will automatically alarm and send a text message to the registered user's mobile phone to facilitate the adoption of corresponding emergency measures.

[0061] Furthermore, the monitoring device also includes a precast concrete block 6. When the construction process cannot be changed, the FRP fiber grating strain gauge 1 is embedded in the concrete aggregate with the same structure mix ratio. A model is made according to the characteristics of the concrete structure, and the model is processed into a precast concrete block 6 that is easy to place and install. The precast concrete block 6 is installed at a designated position during the formal structure construction and the wires are led out to complete the pre-embedding of the FRP fiber grating strain gauge 1.

[0062] In this embodiment, the size of the FRP fiber Bragg grating strain gauge 1 can be customized according to the size of the concrete structure and the monitoring range, and can meet the monitoring of concrete structures of different structural sizes; at the same time, strain gauges of corresponding ranges can be processed according to the concrete strength grade; the FRP fiber Bragg grating strain gauge 1 is designed with waterproof protection and can be directly buried in the concrete structure.

[0063] Preferably, the intelligent monitoring cloud platform adopts a three-dimensional visualization module design, and the three-dimensional visualization monitoring module includes a refined 3D model display unit and a real-scene three-dimensional display unit, which are respectively used to realize the correlation and interaction of monitoring data and measuring points, thereby realizing three-dimensional dynamic visualization query and management of monitoring information of concrete structures during operation.

[0064] refer to Figure 3 The FRP fiber Bragg grating demodulator 2 includes a demodulator network interface 9, a demodulator power interface 10, a demodulator touch screen 11, a demodulator fiber Bragg grating interface 12 and a rechargeable lithium battery (not shown), wherein:

[0065] The demodulator network interface 9 is arranged on the side of the FRP fiber grating demodulator 2 and is connected to the communication transmission module 3 via a network cable;

[0066] The demodulator power interface 10 is arranged on the side of the FRP fiber Bragg grating demodulator 2, and is connected to an external power source through a wire to charge the rechargeable lithium battery built into the FRP fiber Bragg grating demodulator 2;

[0067] The demodulator touch screen 11 is arranged on the upper surface of the FRP fiber grating demodulator 2, and is used to intuitively display the internal structure state of the concrete. At the same time, the calculation formula can be edited to select the corresponding calculation formula for the concrete structure of different strength grades to ensure the high accuracy of the calculation;

[0068] The demodulator fiber Bragg grating interface 12 is arranged on the side of the FRP fiber Bragg grating demodulator 2 and is connected to the FRP fiber Bragg grating strain gauge 1 through an optical fiber armored line.

[0069] In one embodiment, the external power source is a solar power generation module 4, and the solar power generation module 4 is connected to the FRP fiber Bragg grating demodulator 2 by a power wire, and is used to install a solar power generation panel under outdoor conditions with abundant sunlight to power the rechargeable lithium battery of the FRP fiber Bragg grating demodulator 2.

[0070] In another embodiment, the external power source is a wind power generation module 5, and the wind power generation module 5 is connected to the FRP fiber Bragg grating demodulator 2 by a power wire, which is used to install a small wind turbine in a place where sunlight cannot reach, such as a tunnel, to provide clean energy for the FRP fiber Bragg grating demodulator 2.

[0071] refer to Figure 2 The FRP fiber Bragg grating strain gauge 1 includes an FRP fiber Bragg grating sensing point 7 and an FRP fiber Bragg grating stress disk 8 installed on the optical fiber inside the concrete structure. When the FRP fiber Bragg grating sensing point 7 is squeezed or the FRP fiber Bragg grating stress disk 8 is under stress, the corresponding strain value is displayed in real time on the touch screen 11 of the demodulator.

[0072] Preferably, the FRP fiber grating strain gauge 1 can fix multiple FRP fiber grating sensing points 7 in one FRP fiber grating strain gauge 1 and be used in large concrete structures; or, multiple FRP fiber grating strain gauges 1 can be connected in series, that is, connected end to end, and led out to the outside of the concrete structure with a wire.

[0073] Preferably, the communication transmission module 3 is updated accordingly according to the signal base station in the project area, using 3G signals for network transmission in remote areas and using 4G / 5G signals for network transmission in highly developed areas.

[0074] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A concrete internal structure status monitoring device based on FRP fiber Bragg grating, characterized in that: It includes FRP fiber Bragg grating strain gauge, FRP fiber Bragg grating demodulator, communication transmission module, intelligent monitoring cloud platform and precast concrete blocks, among which: The FRP fiber Bragg grating strain gauge is pre-buried in the weak part of the structure that needs to be monitored before the concrete is poured. One end is led out to the outside of the concrete structure through the fiber armored line, and the other end is connected to the FRP fiber Bragg grating demodulator through the fiber armored line to transmit the measurement signal inside the concrete structure to the FRP fiber Bragg grating demodulator. The FRP fiber Bragg grating demodulator is connected to the communication transmission module and is used to demodulate the measurement signal of the FRP fiber Bragg grating strain gauge to obtain the strain data inside the concrete structure; The communication transmission module is connected to the FRP fiber Bragg grating demodulator through a wire or is built into the FRP fiber Bragg grating demodulator, and is used to upload the strain data inside the concrete structure to the intelligent monitoring cloud platform; The intelligent monitoring cloud platform is connected to the FRP fiber grating demodulator through the communication transmission module, and is used for: Remotely control the working state of the FRP fiber Bragg grating demodulator through the communication transmission module; Receive and store the real-time measurement data uploaded by the communication transmission module; Combined with the initial selection of concrete structure grade and the real-time status of the concrete structure stress concentration area, the algorithm is converted and analyzed to display the internal structure strain value of the concrete and the corresponding safety level in real time; The user logs in to the intelligent monitoring cloud platform remotely through a PC or APP to access cloud data and thus grasp the safety and health status of the concrete structure in real time; The intelligent monitoring cloud platform adopts a three-dimensional visualization module design, which includes a refined 3D model display unit and a real-scene three-dimensional display unit, which are respectively used to realize the correlation and interaction between monitoring data and measuring points, thereby realizing three-dimensional dynamic visualization query and management of monitoring information of concrete structures during operation; The FRP fiber Bragg grating strain gauge is embedded in the concrete aggregate with the same structural mix ratio as the concrete to be monitored, a model is made according to the characteristics of the concrete structure, and the model is processed into a precast concrete block, which is used to install the precast concrete block at a designated position during the formal structure construction and lead out the wire to complete the embedding of the FRP fiber Bragg grating strain gauge; The FRP fiber Bragg grating demodulator includes a demodulator network interface, a demodulator power interface, a demodulator touch screen, a demodulator fiber Bragg grating interface and a rechargeable lithium battery, wherein: The demodulator network interface is arranged on the side of the FRP fiber grating demodulator and is connected to the communication transmission module via a network cable; The demodulator power interface is arranged on the side of the FRP fiber Bragg grating demodulator, and is connected to an external power source through a wire to charge a rechargeable lithium battery built into the FRP fiber Bragg grating demodulator; The demodulator touch screen is arranged on the upper surface of the FRP fiber grating demodulator, and is used to intuitively display the internal structure state of the concrete. At the same time, the calculation formula can be edited to select the corresponding calculation formula for concrete structures of different strength grades, thereby ensuring high calculation accuracy; The demodulator fiber Bragg grating interface is arranged on the side of the FRP fiber Bragg grating demodulator and is connected to the FRP fiber Bragg grating strain gauge through an optical fiber armored line; The external power source is a solar power generation module, which is connected to the FRP fiber Bragg grating demodulator by a power wire, and is used to power the rechargeable lithium battery of the FRP fiber Bragg grating demodulator under the condition of abundant outdoor sunlight; or, the external power source is a wind power generation module, which is connected to the FRP fiber Bragg grating demodulator by a power wire, and is used to provide clean energy for the FRP fiber Bragg grating demodulator in places such as tunnels where sunlight cannot reach; The FRP fiber Bragg grating strain gauge includes an FRP fiber Bragg grating sensing point and an FRP fiber Bragg grating stress disk installed on the optical fiber inside the concrete structure. When the FRP fiber Bragg grating sensing point is squeezed or the FRP fiber Bragg grating stress disk is under stress, the corresponding strain value is displayed in real time on the touch screen of the demodulator.

2. A concrete internal structure state monitoring device based on FRP fiber Bragg grating according to claim 1, characterized in that: The FRP fiber Bragg grating strain gauge can fix multiple FRP fiber Bragg grating sensing points in one FRP fiber Bragg grating strain gauge and be used in large concrete structures; or, multiple FRP fiber Bragg grating strain gauges can be connected in series and led out to the outside of the concrete structure with one wire.

3. The concrete internal structure state monitoring device based on FRP fiber Bragg grating according to claim 1 is characterized in that: The communication transmission module is updated accordingly according to the signal base station in the project area, using 3G signals for network transmission in remote areas and 4G / 5G signals for network transmission in highly developed areas.

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