Electromagnetic elastic absolute strain monitoring device and method

Abstract

The application discloses an electromagnetic elastic absolute strain monitoring device and method, the device comprises a force element, an electromagnetic elastic absolute stress sensor and a magnetic elastic instrument; the method determines an absolute strain monitoring position according to monitoring requirements, pours a structure and embeds the force element and the sensor at the corresponding position, calculates the absolute stress of the force element due to the cooperative deformation according to the signal collected by the sensor during work, and according to the constitutive relation of the force element, the absolute stress of the force element can be converted into the absolute strain. The surface of the force element is processed with a bite thread, and the two ends are provided with support joints, so that the force element can be deformed cooperatively with the structure without slip, and therefore the absolute strain of the force element is the absolute strain of the structure in the measured area. The application directly monitors the absolute strain, and compared with the traditional relative strain monitoring method, the application has higher precision, longer service life, stronger anti-risk ability, higher installation survival rate, smaller influence of environment and can realize long-term absolute strain monitoring.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of civil engineering structure health monitoring, and particularly relates to an electromagnetic elastic absolute strain monitoring device and method. BACKGROUND

[0002] Engineering structures will be subjected to various factors in the environment such as load, wind, complex geological conditions and other various interference factors during use, thereby producing different degrees of static and dynamic deformation. When the deformation of the engineering structure exceeds the specified limit, it will affect its normal use, and in severe cases, it may cause structural failure, endangering human life and safety. For example, the famous Quebec Bridge in Canada collapsed due to the calculation error of strain, causing excessive strain of the cantilever during installation, resulting in huge losses. Therefore, it is particularly important to monitor the deformation of engineering structures under construction and in use for a long time and accurately. Strain, as a very important indicator of structural deformation, is generally very small in value and is not easy to monitor in large-scale structures, so various types of strain sensors are needed; however, the monitoring accuracy, continuity of monitoring, and convenience of sensor installation of various types of sensors are very important and urgent problems to be solved.

[0003] The existing strain monitoring equipment has some key problems to be solved in monitoring absolute strain. For example, the Chinese patent application with publication number CN107367339A proposes an absolute strain detection method and a special strip-shaped pattern, which uses the change of resistance of a metal conductor when the metal conductor is subjected to strain to monitor the strain of a structure. The resistance strain gauge must be balanced before monitoring the strain. If the bridge balance is exactly at the zero strain moment, the absolute strain can be measured. However, the power failure that cannot be predicted will cause the re-balance of the bridge, and the strain measured thereafter is the relative strain. The existing technology does not mention how to overcome the problem of re-balance after power failure. Even in short-term testing, assuming that there is no power failure causing bridge rebalancing, this method needs to completely cut and separate the strip-shaped sample with the strain gauge pasted thereon from the surface of the concrete structure, which not only damages the structure to be tested, but also is very cumbersome and inefficient. The Chinese patent application with publication number CN221404224U proposes a vibrating wire strain gauge, which uses the change of the vibration frequency of the tensioned wire to monitor the strain of the structure. In theory, as long as the structure strain is zero at the time of installation, the absolute strain can be measured. However, the metal wire will be fatigued in a long and tight state, thereby affecting the strain monitoring accuracy and long-term stability, and the installation process of the vibrating wire strain gauge is relatively cumbersome, with strict requirements for the installation environment, and needs to be accurately fixed to ensure the measurement accuracy.

[0004] In addition, the Chinese patent application with the publication number CN118347420A proposes a method for indirectly measuring the deflection of a bridge span by strain measurement, which uses a fiber Bragg grating strain sensor to contactively measure the absolute strain of the bridge span. Although the fiber Bragg grating strain sensor can ensure accuracy and stability, the fiber Bragg grating is prone to breakage when embedded in concrete, and when installed on the outside of the concrete to measure strain, it is prone to breakage under large deformation, has a low survival rate and high cost.

[0005] Therefore, it is urgent for the engineering to develop a concrete absolute strain monitoring device with high precision, long-term stability and low cost. SUMMARY

[0006] In view of the above, the present application provides an electromagnetic elastic absolute strain monitoring device and method, which can overcome the shortcomings of short service life of traditional strain monitoring sensors and inability to perform long-term monitoring, accurately monitor the absolute strain within the allowable error range of engineering, and does not require complex calculations, has a simple principle and high monitoring efficiency, and can achieve long-term continuous monitoring, providing a simple and efficient absolute strain monitoring solution for bridge engineering and other strain monitoring requirements.

[0007] An electromagnetic elastic absolute strain monitoring device, comprising:

[0008] A force receiving element embedded in a structure (such as concrete) in a measured area or welded (or pasted) to the surface of the structure in the measured area, and consistent with the force direction of the structure in the measured area;

[0009] An electromagnetic elastic absolute stress sensor installed on the force receiving element for collecting a magnetic characteristic electric signal at the force receiving element;

[0010] A magnetic elastic instrument for calculating and determining the absolute stress of the force receiving element according to the magnetic characteristic electric signal, and further converting the absolute stress of the force receiving element into the absolute strain of the structure in the measured area according to the constitutive relationship of the force receiving element calibrated in the laboratory.

[0011] Further, the electromagnetic elastic absolute stress sensor comprises a support framework, and a magnetic field generating element and a magneto-electric sensing element fixedly installed on the support framework, the magnetic field generating element is controlled by the magnetic elastic instrument to generate a magnetic field in the measured area, thereby magnetizing the force receiving element; the magneto-electric sensing element generates a magnetic characteristic electric signal representing the magnetic induction intensity at the force receiving element through electromagnetic induction.

[0012] To ensure that the electromagnetic elastic absolute stress sensor can accurately measure the absolute stress of the force receiving element, further, the force receiving element is made of a steel wire, a steel strand or a screw rod (with a small diameter), and is in an elastic stage in or on the surface of the structure in the measured area, so as to avoid the influence of the plastic region on the measurement result.

[0013] To ensure the absolute strain of the force element is the absolute strain of the structure, measures are taken to ensure full contact between the structure and the force element and no relative slip occurs; further, the force element is processed with a bite thread to increase the bite force and resistance between the structure and the element surface.

[0014] To ensure the integrity of the force element and the structure and avoid slip, further, support joints are fixed at both ends of the force element to limit its slip along the structure; if the force element is a steel wire or a steel strand, the support joint can be a steel plate welded with the steel wire or the steel strand; if the force element is a screw rod, the support joint can be a nut threadedly matched with the screw rod.

[0015] Further, the magnetoelastic instrument receives the magnetic characteristic electric signals collected from the electromagnetic elastic absolute stress sensor, and determines the absolute stress of the force element according to the magnetic characteristic electric signal curves of the force element under different stress sizes, and further converts the absolute stress into the absolute strain of the force element according to the constitutive relation of the force element calibrated in the laboratory, since there is a cooperative deformation relationship between the structure and the force element, the absolute strain of the force element is the absolute strain of the structure in the measured region.

[0016] Further, the electromagnetic elastic absolute strain monitoring device further comprises an information interaction device, the magnetoelastic instrument can transmit the absolute stress of the force element and the absolute strain of the structure in the measured region to the upper computer for display for the user to view through the information interaction device.

[0017] The application method of the above electromagnetic elastic absolute strain monitoring device comprises the following steps:

[0018] (1) determining the monitoring region of the absolute strain according to the monitoring demand of the engineering project;

[0019] (2) collecting the magnetic characteristic electric signals at the force element under different stress sizes using the electromagnetic elastic absolute stress sensor, and obtaining the magnetic characteristic electric signal curves of the force element under different stress sizes through fitting;

[0020] (3) pouring the structure in the monitoring region and burying the force element and the electromagnetic elastic absolute stress sensor at the corresponding positions in the monitoring region during the process, or welding (or pasting) the force element on the surface of the structure and sleeving the electromagnetic elastic absolute stress sensor on the force element;

[0021] (4) when the structure in the monitoring region is deformed under the action of external force, the magnetoelastic instrument receives the magnetic characteristic electric signals collected from the electromagnetic elastic absolute stress sensor at the force element, and determines the absolute stress of the force element according to the magnetic characteristic electric signal curves;

[0022] (5) The magnetoelastic instrument converts the absolute stress into the absolute strain of the force element according to the constitutive relation of the force element calibrated in the laboratory, and the absolute strain of the force element is the absolute strain of the structure of the monitoring area due to the cooperative deformation relation between the structure and the force element.

[0023] Based on the above technical solution, the creativity of the application mainly lies in the following aspects:

[0024] 1. The measured strain is absolute strain. Compared with the resistance strain gauge, the relation between the absolute stress and the magnetic characteristic quantity is calibrated in advance, so that the relation between the absolute stress and the magnetic characteristic quantity will not change even if the power is suddenly cut off and then turned on during the monitoring process, and the monitoring result will not be affected, and the detected absolute strain of the structure is still detected, so that the application is suitable for long-term monitoring and the monitoring result is stable.

[0025] 2. The application converts the absolute strain monitoring of the structure into the absolute strain monitoring of the force element, and the surface and boundary of the force element are specially treated, the force element is provided with the engagement thread on the surface and the steel plate or nut at the two ends, so that the force element can be tightly connected with the structure to realize the cooperative deformation, the absolute strain of the ferromagnetic element is indirectly monitored to monitor the absolute strain of the structure, and a new idea is provided for the absolute strain monitoring of the structure.

[0026] 3. The application is directly embedded in the structure, and the configured sensor can be directly embedded in the specific position of the structure during pouring, the installation process is convenient, the structure can be ingeniously used as the protective layer of the application, and there is no need to specially design the protection measure, and the application is less affected by the environment; compared with the sensor exposed in the environment for a long time, the service life of the application is longer.

[0027] 4. The fiber Bragg grating is a brittle material, and is easy to be brittle under the action of impact and excessive bending, so the fiber Bragg grating is easy to be broken and has a low survival rate if not properly handled during embedding. Compared with the embedded fiber Bragg grating strain sensor, the force element used in the application is mainly steel wire, steel strand or threaded rod, so the strength of the force element is high, and the force element will not be damaged during the installation of the sensor, pouring of the structure and a series of process, and the survival rate is high.

[0028] The application converts the absolute strain monitoring of the structure into the absolute strain monitoring of the force element through the cooperative deformation of the force element and the structure, and provides a simple and effective absolute strain monitoring method; compared with the prior art, the application has at least the following beneficial technical effects:

[0029] 1. Compared with the vibrating wire strain gauge, the vibrating wire strain gauge uses the change of the vibrating frequency of the tight metal string to monitor the strain, but the tight string is prone to fatigue problems; while the present application uses steel wire, steel strand or threaded rod and the like, and does not need to be pre-stretched during installation, and secondly, the absolute strain monitoring range is maintained in the elastic working stage of the stress element, and is not prone to fatigue problems, and has high long-term stability.

[0030] 2. Compared with the resistance strain gauge, the resistance strain gauge needs to be balanced before measurement, and needs to be balanced again after power off, which is difficult to achieve during monitoring, and has poor absolute strain monitoring effect and weak risk resistance ability; while the present application only needs to be simply calibrated before installation to continuously and stably monitor the absolute strain after installation, and the strain monitoring result will not be affected even if the power is off, and the risk resistance ability is strong.

[0031] 3. Compared with the embedded optical fiber grating strain sensor, the optical fiber grating itself is a brittle material, which is prone to brittle fracture under impact and excessive bending, and therefore is prone to fracture if not handled properly during embedding, and has low survival rate; while the stress element used in the present application is mainly steel wire, steel strand or threaded rod, and therefore has high strength and is not prone to damage during installation, and has higher survival rate. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structural schematic view of the electromagnetic elastic absolute strain monitoring device of the present application.

[0033] Figure 2 It is a schematic view of the sensor and stress element arrangement for the bridge compression zone concrete absolute strain monitoring embodiment.

[0034] Figure 3 It is a schematic view of the monitoring method flow of the electromagnetic elastic absolute strain monitoring device of the present application.

[0035] Figure 4 It is a schematic view of the stress element pressure-magnetic characteristic electric signal calibration curve, in which F is the axial pressure applied to the stress element during calibration, x is the magnetic characteristic electric signal, the red color is the calibration point, and the blue color is the fitting curve.

[0036] Figure 5 It is a schematic view of the stress element pressure stress-pressure strain calibration curve, in which σ is the pressure stress of the stress element, ε is the pressure strain under the corresponding stress, the red color is the calibration point, and the blue color is the fitting curve.

[0037] Figure 6 It is a schematic view of the relationship curve between the stress element pressure strain and the magnetic characteristic electric signal, in whichε refers to the strain of the force receiving element, x refers to the corresponding magnetic characteristic quantity, red is the calibration point, and blue is the fitting curve.

[0038] Figure 7 is a comparison diagram of the monitoring results of the system and the vibrating wire strain gauge.

[0039] Figure 8 is a schematic diagram of one of the embedding methods of the electromagnetic elastic absolute stress sensor. DETAILED DESCRIPTION

[0040] In order to more specifically describe the present application, the technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments.

[0041] As shown in Figure 1 , the electromagnetic elastic absolute strain monitoring device of the present application comprises a force receiving element 3-01, an electromagnetic elastic absolute stress sensor 3-04, and a magnetoelastic instrument 3-05, wherein the force receiving element 3-01 is embedded in the concrete of the measured area and is consistent with the stress direction of the concrete of the measured area; the electromagnetic elastic absolute stress sensor 3-04 is installed on the force receiving element 3-01 and is used to collect the magnetic characteristic electric signal at the force receiving element 3-01; the magnetoelastic instrument 3-05 calculates and determines the absolute stress of the force receiving element 3-01 according to the magnetic characteristic electric signal, and then converts the absolute stress of the force receiving element 3-01 into the absolute strain of the concrete of the measured area according to the constitutive relationship of the force receiving element 3-01 calibrated in the laboratory. S .

[0042] The force receiving element 3-01 can be a steel wire, a steel strand, or a small-diameter screw rod, and is in the elastic stage in the concrete of the measured area; the force receiving element 3-01 is processed with a biting thread 3-02 to increase the biting force and resistance between the concrete and the surface of the element, and both ends are fixed with support joints 3-03 to limit its sliding along the concrete. If the force receiving element 3-01 is a steel wire or a steel strand, the support joint 3-03 can be welded with a steel plate and a steel wire or a steel strand; if the force receiving element 3-01 is a screw rod, the support joint 3-03 can be screwed with a nut.

[0043] The electromagnetic elastic absolute stress sensor 3-04 comprises a support framework and a magnetic field generating element and a magneto-electric sensing element installed and fixed on the support framework, the magnetic field generating element is controlled by the magnetoelastic instrument 3-05 and is used to generate a magnetic field in the measured area, thereby magnetizing the force receiving element 3-01; the magneto-electric sensing element generates a magnetic characteristic electric signal representing the magnetic field strength at the force receiving element 3-01 through electromagnetic induction. The magnetic field generating element can be realized by using a field coil, and the magneto-electric sensing element can be realized by using a Hall element, without the need for an external power supply and without the need for integration.

[0044] The magnetic piezometer 3-05 receives the magnetic characteristic electric signal collected by the electromagnetic piezoelectric absolute stress sensor 3-04, and calculates and determines the absolute stress of the stress element 3-01 according to the magnetic characteristic electric signal curve of the stress element 3-01 under different stress sizes, and then converts the absolute stress into the absolute strain of the stress element 3-01 according to the constitutive relation of the stress element 3-01 calibrated in the laboratory. Since there is a cooperative deformation relationship between the concrete and the stress element 3-01, the absolute strain of the stress element 3-01 is the absolute strain of the concrete in the measured region, and is finally displayed in the upper computer through interaction.

[0045] The method for monitoring the absolute strain of concrete by using the above system is as shown in Figure 3

[0046] In the preparation stage, according to the target concrete structure strain monitoring range, a suitable stress element is selected, and the requirements of the stress element are as follows:

[0047] ① Since the stress element needs to be deformed cooperatively with the concrete, the stress element should be in the elastic stage and not enter the plastic stage within the rated strain change range.

[0048] ② The stress element needs to be a threaded steel wire, steel strand or screw rod.

[0049] Then the electromagnetic piezoelectric absolute stress sensor is sleeved on the selected stress element, and the stress element is installed on the calibration frame, and the both ends are fixed with nuts; the sensor is connected to the magnetic piezometer, and the magnetic piezometer has a temperature sensor; the sensor is powered on, and the stress element is subjected to pressure by the jack. At this time, the electromagnetic piezoelectric absolute stress sensor receives the change of this characteristic, converts it into voltage data and transmits it to the magnetic piezometer. Since the magnetic piezometer is embedded with a calibration program, it will give the corresponding relationship between voltage and tension at a given temperature, thereby completing the calibration work, and obtaining the calibration curve of the stress element pressure-magnetic characteristic electric signal as shown in Figure 4

[0050] Further, the constitutive test of the stress element is carried out, and the stress-strain curve thereof is drawn, as shown in Figure 5

[0051] After the above calibration, the stress element strain-magnetic characteristic electric signal relationship curve can be further obtained, as shown in Figure 6

[0052] ​​​​During the pouring stage, the absolute strain monitoring location is first determined according to the monitoring requirements of the project. The force-bearing element equipped with an electromagnetic spring-type absolute stress sensor is then firmly tied to the corresponding position in the steel cage before pouring concrete.

[0053] During the working phase, when the concrete deforms, an electromagnetic elastic absolute stress sensor collects the magnetic characteristic electrical signal at the stress-bearing component and provides it to the magnetoelastic instrument. The magnetoelastic instrument calculates and determines the absolute stress of the stress-bearing component based on the magnetic characteristic electrical signal curves of the component under different stress magnitudes. Furthermore, based on the constitutive relationship of the force-bearing element calibrated in the laboratory (i.e., stress... With strain The relationship curve (which represents the absolute stress of the stressed element) Transformed into absolute strain of the stressed element Due to the cooperative deformation relationship between concrete and load-bearing components, the absolute strain of the load-bearing components... That is, the absolute strain of the concrete in the tested area. , and output the final result.

[0054] Example

[0055] The electromagnetic spring-type absolute strain monitoring device and method of this invention can theoretically be used for absolute strain monitoring of any concrete structure or other material components. This embodiment uses the absolute strain monitoring of the tension zone of reinforced concrete bridges as an example. The arrangement of the components and sensors in the system is as follows: Figure 2 As shown, the specific implementation method is as follows:

[0056] First, the stress-bearing element 3-01 is embedded in the location where strain monitoring is required. The embedding process is as follows: before pouring the concrete structure, the reinforcing cage is tied. After determining the absolute strain monitoring location, the stress-bearing element equipped with the electromagnetic spring-type absolute stress sensor is tied and installed at the corresponding position in the reinforcing cage. Then, the concrete is poured to complete the sensor embedding. Figure 8 As shown, the entire process is simple and easy to install. The orientation of the force-bearing element 3-01 should be consistent with the actual force direction of this part in the bridge's concrete structure 1. The sensor placement is determined according to the requirements of different engineering structures; multiple sensors can be embedded in the same structure simultaneously. For simply supported beam bridges, the sensors in this embodiment can be placed on the compression side at mid-span.

[0057] To ensure that the concrete absolute strain monitoring system 3 can accurately monitor strain, the stress element 3-01 should be prevented from entering the plastic stage. Therefore, when designing the sensor, a suitable stress element should be selected so that it is elastic within the strain range that needs to be monitored.

[0058] After the concrete is poured, the preliminary work is completed, and the unstressed state at this time is the initial reference state.

[0059] When the concrete structure or component is in operation, it will be deformed at the corresponding position due to its own gravity and various external forces; correspondingly, the force-bearing element 3-01 will also be deformed cooperatively with the concrete due to the special thread treatment on its surface and the restriction of the steel plates or nuts on both sides, thereby generating stress, and the stress size will be collected by the electromagnetic elastic absolute stress sensor 3-04 in the form of magnetic characteristic electric signal and transmitted to be displayed on the magneto-elastic instrument 3-05.

[0060] The force-bearing element 3-01 has been calibrated its stress-strain relationship in the laboratory before installation, so the absolute stress measured by the electromagnetic elastic absolute stress sensor 3-04 can be converted into the absolute strain of the force-bearing element 3-01 according to this relationship .

[0061] The force-bearing element 3-01 in the concrete absolute strain monitoring system 3 of the embodiment has the form as shown in Figure 1 .

[0062] In order to ensure that the absolute strain of the force-bearing element is the absolute strain of the concrete, measures need to be taken to ensure that the concrete and the force-bearing element are in full contact and do not produce relative slip, and the force-bearing element 3-01 is provided with a biting thread 3-02 to increase the biting force and resistance between the concrete and the surface of the element.

[0063] In order to ensure the integrity of the force-bearing element and the concrete and avoid slip, two support joints 3-04 are fixed at both ends of the force-bearing element 3-01 to limit the slip between the concrete and the element.

[0064] Due to the above treatment, it can be considered that the bridge concrete 1 and the force-bearing element 3-01 are cooperatively deformed, and the absolute strains of the two should be equal, that is .

[0065] Since the monitoring is based on the initial reference state of the structure under no stress, the obtained concrete strain is the absolute strain of the bridge concrete 1 .

[0066] Verification Example

[0067] In order to monitor the absolute strain size of the concrete material under tension, a suitable force-bearing element needs to be selected first, and here a steel strand with a treated surface is selected as the force-bearing element, and the force-magnetic characteristic electric signal relationship curve is obtained by calibrating the force-magnetic characteristic electric signal relationship of the force-bearing element at different temperatures on a calibration frame in the laboratory. Then the same force-bearing element is further calibrated for the constitutive relationship curve in the elastic stage, and the constitutive relationship curve is as shown in Figure 5 . (Mpa); from the above two calibration results, the relationship curve between strain and magnetic characteristic quantity can be obtained, as shown inFigure 7 The force-receiving element is connected and installed with the electromagnetic elastic absolute stress sensor after calibration, and is buried in the corresponding position according to the burying method of the present application. Figure 8 In the working process, the force-receiving element will be deformed due to the gravity and external load, and thus the strain is generated. Since the force-receiving element is not compressed or stretched in the axial direction during the burying of the sensor, the strain of the force-receiving element measured is the absolute strain of the concrete.

[0068] Table 1

[0069]

[0070] From the results of the above table and Figure 7 It can be seen that the error between the absolute strain of the concrete measured by the present application and the strain measured by the vibrating wire strain gauge is within 5%, and thus the present application has good precision.

[0071] The above description of the embodiments is for facilitating the understanding and application of the present application by the ordinary skilled in the art, and the skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications made to the present application by the skilled in the art according to the disclosure of the present application should be within the protection scope of the present application.

Claims

1. An electromagnetic elastomeric absolute strain monitoring device, characterized by, The application relates to a monitoring system for monitoring the absolute strain of a structure, which comprises the following parts: a force-bearing element, which is embedded in a structure to be monitored or welded to the surface of the structure to be monitored and is consistent with the force direction of the structure to be monitored; an electromagnetic elastic absolute stress sensor, which is installed on the force-bearing element and used for collecting a magnetic characteristic electric signal at the force-bearing element; a magnetic elastic instrument, which is used for calculating the absolute stress of the force-bearing element according to the magnetic characteristic electric signal, and then converting the absolute stress of the force-bearing element into the absolute strain of the structure to be monitored according to the constitutive relation of the force-bearing element calibrated in a laboratory; the force-bearing element is a steel wire, a steel strand or a screw rod, and is in an elastic stage in the structure to be monitored or on the surface of the structure to be monitored; the force-bearing element is processed with a clamping thread, and support joints are fixed at the two ends of the force-bearing element; if the force-bearing element is a steel wire or a steel strand, the support joints are welded with steel plates and the steel wire or the steel strand; if the force-bearing element is a screw rod, the support joints are screwed with nuts; the magnetic elastic instrument receives the magnetic characteristic electric signal collected by the electromagnetic elastic absolute stress sensor, and calculates the absolute stress of the force-bearing element according to the magnetic characteristic electric signal curve of the force-bearing element under different stress sizes, and then converts the absolute stress into the absolute strain of the force-bearing element according to the constitutive relation of the force-bearing element calibrated in the laboratory; since there is a cooperative deformation relationship between the structure and the force-bearing element, the absolute strain of the force-bearing element is the absolute strain of the structure to be monitored.

2. The electromagnetic ballistic absolute strain monitoring device of claim 1, wherein: the electromagnetic elastic absolute stress sensor comprises a support framework, a magnetic field generating element and a magneto-electric sensing element which are fixed on the support framework; the magnetic field generating element is controlled by the magnetic elastic instrument and is used for generating a magnetic field in the monitored area so as to magnetize the force-bearing element; the magneto-electric sensing element generates a magnetic characteristic electric signal representing the magnetic induction intensity at the force-bearing element through electromagnetic induction.

3. The electromagnetic ballistic absolute strain monitoring device of claim 1, wherein: The monitoring system further comprises an information interaction device, and the magnetic elastic instrument transmits the absolute stress of the force-bearing element and the absolute strain of the structure to be monitored to an upper computer through the information interaction device for display so as to be viewed by a user.

4. The application method of the electromagnetic elastic absolute strain monitoring device according to any one of claims 1 to 3, which comprises the following steps: (1) determining the monitoring area of the absolute strain according to the monitoring requirement of an engineering project; (2) collecting the magnetic characteristic electric signal at the force-bearing element under different stress sizes by using the electromagnetic elastic absolute stress sensor, and obtaining the magnetic characteristic electric signal curve of the force-bearing element under different stress sizes through fitting; (3) pouring a structure in the monitoring area and embedding the force-bearing element and the electromagnetic elastic absolute stress sensor at the corresponding position of the monitoring area in the process, or welding the force-bearing element to the surface of the structure and sleeving the electromagnetic elastic absolute stress sensor on the force-bearing element; (4) when the structure in the monitoring area is deformed under external force, the magnetic elastic instrument receives the magnetic characteristic electric signal collected by the electromagnetic elastic absolute stress sensor at the force-bearing element, and calculates the absolute stress of the force-bearing element according to the magnetic characteristic electric signal curve. (5) The magneto-elastic instrument converts the absolute stress into the absolute strain of the force-bearing element according to the constitutive relation of the force-bearing element calibrated in the laboratory, and the absolute strain of the force-bearing element is the absolute strain of the monitoring region structure body due to the cooperative deformation relation between the structure body and the force-bearing element.

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