Foundation bolt corrosion detection system based on microwave detection and detection method thereof
Through a system based on microwave detection technology, the transmission coefficient frequency domain map of anchor bolts is used to penetrate the tower base to detect the anchor bolts, and the problem of deep corrosion detection of anchor bolts in the existing technology is solved, and non-contact non-destructive detection and accuracy are achieved Evaluation, suitable for anchor bolts of different environments and models.
Patent Information
- Application Number
- CN202311513202.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-10
- Publication Date
- 2024-12-06
AI Technical Summary
The existing anchor bolt detection methods are difficult to effectively detect deep corrosion, especially the ultrasonic waveguide method requires coupling agent and the detection depth is limited. The magnetic powder detection method can only detect surface and shallow corrosion, and the accuracy depends on the experience of the detector.
Adopting a anchor bolt corrosion detection system based on microwave detection technology, using microwave generator, transmitting antenna, receiving antenna and spectrum analyzer, the transmission coefficient frequency domain map of anchor bolts is detected through microwave signals through the tower base, and combined with cloud databases. Differential analysis to realize non-contact non-destructive testing.
The concealment detection of anchor bolt corrosion is achieved, the depth limitation and coupling agent use problems in traditional methods are avoided, and the more accurate corrosion evaluation and rapid detection capabilities are provided, which are suitable for anchor bolts in different models and environments.
Smart Images
Figure HDA0004548109350000011 
Figure HDA0004548109350000012 
Figure HDA0004548109350000021
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of anchor bolt detection, and in particular to an anchor bolt corrosion detection system and a detection method thereof based on microwave detection. Background Art
[0002] The pole tower anchor bolts are important load-bearing components of the transmission tower. During the actual operation, the external forces on the various parts of the tower will form an upward pull and downward pressure on the tower foundation fixed by the anchor bolts, and transmit them to the ground through the concrete foundation. During the operation, due to long-term exposure to harsh outdoor environments, the pole tower anchor bolts will inevitably corrode. Corrosion will reduce the cross-sectional area of the anchor bolts, affect their mechanical strength, and break under the action of strong upward and downward pressure, causing serious power accidents such as the collapse of the tower, resulting in large-scale power outages, large economic losses and even casualties. Therefore, timely detection and repair of the corrosion of the pole tower anchor bolts is particularly important. However, since the anchor bolts are deeply embedded in the tower base, the corrosion phenomenon is hidden and difficult to detect directly, so the effective detection method has always been the focus and difficulty of the project.
[0003] The existing anchor bolt detection methods mainly include cylindrical ultrasonic guided wave method and magnetic particle detection method, such as Figure 1 As shown. The cylindrical ultrasonic guided wave method uses the characteristic that ultrasonic waves can propagate long distances along the cylindrical surface to detect the corrosion of anchor bolts. When the ultrasonic wave encounters the rod wall, it will be reflected and continue to propagate in the cylindrical surface with low loss. Its propagation process can be known by observing its return waveform. When it encounters a defect during propagation, the location of the defect can be reflected in the echo image. However, this method requires a coupling agent and is complicated to operate. Improper handling of the coupling agent will also affect the bolts and the environment. The magnetic particle detection method applies a magnetic field to the object to be tested or directly energizes it, so that a magnetic field with regular direction and size is induced inside it. Magnetic powder is evenly sprinkled on its surface, and the magnetic powder will be distributed according to the law of the magnetic field. When corrosion defects appear on the surface or near the surface of the test object, the surrounding magnetic field will be distorted. The existence of defects can be clearly observed by observing the distribution state of the magnetic powder. For example, a Chinese patent application (publication number CN116448869A) discloses a method for detecting the corrosion degree of carbon steel and stainless steel composite pipes, which solves the problem that the existing pipeline corrosion detection methods are inaccurate and cannot be generally applied. However, this method can only detect corrosion on the bolt surface and 1 to 2 mm in depth, and the detection accuracy is affected by the experience and ability of the detection personnel. Therefore, it is urgent to propose a system and method that can accurately and effectively detect and evaluate the corrosion of anchor bolts. Summary of the invention
[0004] In order to solve the above problems, the present invention proposes an anchor bolt corrosion detection system based on microwave detection technology based on the limitations of the current anchor bolt corrosion detection method, which realizes non-contact non-destructive detection of anchor bolt corrosion and solves the problems of ultrasonic guided wave method requiring coupling agent and small detection depth of magnetic particle detection method.
[0005] On the one hand, the present invention provides a microwave detection-based anchor bolt corrosion detection system, including a hardware end and a software end, wherein the hardware end at least includes a microwave generator, a transmitting antenna, a transmitting antenna bracket, a receiving antenna, a receiving antenna bracket, and a spectrum analyzer, and the software end at least includes a computer and a cloud database, the transmitting antenna is fixed on the transmitting antenna bracket, the transmitting antenna is connected to the microwave generator, the receiving antenna is fixed on the receiving antenna bracket, the receiving antenna is connected to the spectrum analyzer, the anchor bolt transmission coefficient reference frequency domain spectrum obtained by the spectrum analyzer is stored in the computer and uploaded to the cloud database, the anchor bolt transmission coefficient reference frequency domain spectrum is imported into the spectrum analyzer to obtain the anchor bolt transmission coefficient frequency domain spectrum to be tested, and the difference analysis can be performed by the computer.
[0006] As a preferred technical solution, the heights of the receiving antenna bracket and the transmitting antenna bracket are adjustable and can be bent within a range of -90 to 90 degrees.
[0007] As a preferred technical solution, the transmitting antenna is connected to the microwave output port of the microwave generator through a coaxial cable, and the receiving antenna is connected to the signal input port of the spectrum analyzer through a coaxial cable.
[0008] Another aspect of the present invention provides a method for detecting corrosion of anchor bolts based on microwave detection, which comprises at least the following steps:
[0009] (1) According to the diameter of the anchor bolt to be tested, the microwave frequency band is determined based on the formula, and the transmitting antenna and the receiving antenna corresponding to the port size are selected according to the frequency band, so that the detection frequency band is included in the frequency range of the transmitting antenna and the receiving antenna;
[0010] (2) Fix the transmitting antenna to the transmitting antenna bracket through a clamp, and fix the receiving antenna to the receiving antenna bracket through a clamp;
[0011] (3) connecting the transmitting antenna to the microwave output port of the microwave generator through a coaxial cable, and connecting the receiving antenna to the signal input port of the spectrum analyzer through a coaxial cable, wherein the transmitting antenna emits a microwave signal and the receiving wire receives the transmitted signal;
[0012] (4) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna to perform microwave detection on the uncorroded anchor bolts. The spectrum analyzer obtains the transmission wave frequency domain spectrum corresponding to each scanning point of the anchor bolts, which is stored in the computer as the reference frequency domain spectrum of the anchor bolt transmission coefficient and uploaded to the cloud database;
[0013] (5) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna, perform microwave detection on each scanning point of the anchor bolt to be tested, and use a spectrum analyzer to obtain a frequency domain spectrum of the transmission coefficient of the anchor bolt to be tested;
[0014] (6) Importing the anchor bolt transmission coefficient reference frequency domain spectrum into the anchor bolt transmission coefficient frequency domain spectrum to be tested, and performing frequency domain response difference analysis to obtain the test results. The test results are used to determine whether the anchor bolt is corroded, the severity of the corrosion, and the location of the corrosion point;
[0015] (7) Propose a repair or replacement plan for the anchor bolts based on the test results.
[0016] Preferably, the formula is λ=πd, wherein λ is the microwave frequency band, and d is the diameter of the anchor bolt to be measured.
[0017] Preferably, the transmitting antenna and the receiving antenna are both horn antennas, and the horn antenna is one of a fan-shaped horn antenna, a pyramidal horn antenna, a conical horn antenna, a corrugated horn antenna, a ridged horn antenna, and a multi-mode horn antenna, preferably a ridged horn antenna, and further preferably a pyramidal double-ridged horn antenna.
[0018] Preferably, the range of the angle R of the transmitting antenna and the receiving antenna toward the anchor bolt to be measured is controlled to be -90°<R<90°.
[0019] Preferably, the range of the angle R1 of the transmitting antenna and the receiving antenna toward the corrosion layer (center position) of the anchor bolt to be measured is controlled to be 0°<R1<90°.
[0020] Preferably, each scanning point in the anchor bolt transmission coefficient reference frequency domain spectrum corresponds to each scanning point in the anchor bolt transmission coefficient frequency domain spectrum to be tested. After installation, the anchor screw is first tested to obtain the anchor bolt transmission coefficient reference frequency domain spectrum, which is uploaded to the cloud database. When a problem occurs in the anchor screw and needs to be tested, the matching anchor bolt transmission coefficient reference frequency domain spectrum is called out from the cloud database, and the transmitting antenna and the receiving antenna are adjusted according to the scanning points of the anchor bolt transmission coefficient reference frequency domain spectrum. The transmission coefficient reference frequency domain spectrum of the anchor bolt is obtained. The anchor bolt transmission coefficient reference frequency domain spectrum with the same scanning points is obtained. Subsequently, based on the comparative frequency domain response difference analysis results of the anchor bolt transmission coefficient reference frequency domain spectrum with the same scanning points and the anchor bolt transmission coefficient reference frequency domain spectrum, it is determined whether corrosion occurs, the severity of corrosion, and the corresponding corrosion point location.
[0021] The detection result of the comparative frequency domain response difference analysis is S 21 Amplitude vs. frequency curve comparison, if S 21 If the reference curve and the curve to be tested coincide with each other in the curve comparison diagram of amplitude versus frequency, no corrosion occurs; if S 21 In the comparison of amplitude vs. frequency curves, the curve to be tested shows an S curve relative to the reference curve. 21 The part with reduced amplitude is judged to be corrosion, and the reduced S 21 The larger the amplitude, the more serious the corrosion is, and a treatment plan is proposed based on the degree of corrosion.
[0022] The position of the corrosion point is determined based on the orientation angle of the transmitting antenna and the receiving antenna, the lifting distance and the antenna height, wherein the orientation angle of the transmitting antenna and the receiving antenna is the angle between the transmitting antenna or the receiving antenna and the line connecting the scanning point relative to the horizontal position, the lifting distance is the horizontal distance between the transmitting antenna or the receiving antenna and the edge of the anchor bolt, and the antenna height is the height of the transmitting antenna or the receiving antenna relative to the ground.
[0023] The anchor bolts are wrapped in the concrete tower base, and corrosion often occurs near the ground or below the ground. After the corrosion occurs, it cannot be directly observed. The traditional anchor bolt detection method requires coupling agent or has the problem of small detection depth. The traditional microwave detection cannot be applied to the anchor bolt detection. The anchor bolt corrosion detection system based on microwave detection technology provided by the present invention effectively solves the above problems. In particular, microwave detection is used in conjunction with a pyramid double-ridge horn antenna with adjustable height and angle. The transmitting antenna transmits microwave signals. After the microwave signal penetrates the tower base, it acts on the corroded part of the anchor bolt. The receiving horn antenna receives the transmission signal. The frequency domain spectrum of the transmission coefficient of the anchor bolt to be tested is obtained through a spectrum analyzer. Through comparative analysis, non-contact microwave detection of hidden corrosion of the anchor bolt is realized. Furthermore, by adjusting the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna, microwave detection of each scanning point of the anchor bolt under different models, different bolt burial depths, different tower base thicknesses and different environments can be achieved to avoid missed detection. Based on the on-site conditions, by comprehensively adjusting the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna, a more obvious detection effect is achieved under the adjustment of the lowest microwave divergence and attenuation. The present invention controls the range of the angle R of the transmitting antenna and the receiving antenna toward the anchor bolt to be tested to -90°<R<90° to match the coverage microwave detection of each scanning point of the anchor bolts of different types, different installation conditions and different environments, and further controls the range of the angle R1 of the transmitting antenna and the receiving antenna toward the corrosion layer (center position) of the anchor bolt to be tested to 0°≤R1<90°, especially when 0°≤R1≤45°, to achieve the detection of the part of the anchor bolt under the ground, avoid the occurrence of missed detection and present a more obvious detection effect.
[0024] Preferably, the cloud database includes anchor bolt transmission coefficient reference frequency domain spectra of anchor bolts with different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower foundation thicknesses, and anchor bolts in different environments;
[0025] The cloud database also includes the detection results of the frequency domain response difference analysis of the benchmark frequency domain spectra of the anchor bolt transmission coefficient and the frequency domain spectra of the anchor bolt transmission coefficient to be tested for different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower base thicknesses, and anchor bolts in different environments.
[0026] The establishment of the cloud database in the present invention helps to simplify the detection process. The reference frequency domain spectrum of anchor bolt corrosion is directly called from the cloud, which eliminates the detection process of non-corroded anchor bolts, and realizes rapid detection of anchor bolts of different models in different environments. At the same time, the specific frequency band can be determined by comparing the detection results of frequency domain response difference analysis. The uploading and calling of cloud data are open to all users, realizing rapid expansion of the database.
[0027] Beneficial Effects
[0028] 1. Based on the limitations of the current anchor bolt corrosion detection methods, the present invention proposes an anchor bolt corrosion detection system based on microwave detection technology, which realizes non-contact non-destructive detection of anchor bolt corrosion and solves the problems of ultrasonic guided wave method requiring coupling agent and magnetic particle detection method having a small detection depth.
[0029] 2. This application adopts microwave detection in combination with a pyramidal double-ridged horn antenna with adjustable height and angle. The transmitting antenna transmits microwave signals. The microwave signals penetrate the tower base and act on the corroded parts of the anchor bolts. The receiving horn antenna receives the transmitted signals. The frequency domain spectrum of the transmission coefficient of the anchor bolt to be tested is obtained through a spectrum analyzer. Through comparative analysis, non-contact microwave detection of hidden corrosion of the anchor bolts is achieved.
[0030] 3. This application realizes microwave detection of various scanning points of anchor bolts of different types, different bolt burial depths, different tower base thicknesses and under different environments by adjusting the orientation angles, lifting distances and antenna heights of the transmitting antenna and the receiving antenna to avoid missed detections.
[0031] 4. The system and method provided by the present invention can achieve a more obvious detection effect under the lowest microwave divergence and attenuation by comprehensively adjusting the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna based on the on-site conditions.
[0032] 5. The establishment of the cloud database in the present invention helps to simplify the detection process. The reference frequency domain spectrum of anchor bolt corrosion is directly called from the cloud, which eliminates the detection process of non-corroded anchor bolts and realizes rapid detection of anchor bolts of different models in different environments. At the same time, the specific frequency band can be determined by comparing the detection results of the frequency domain response difference analysis. The uploading and calling of cloud data are open to all users, realizing rapid expansion of the database. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1It is a schematic diagram of the existing cylindrical ultrasonic guided wave method and magnetic particle detection method, in which a is the cylindrical ultrasonic guided wave method, a1 is the anchor bolt, a2 is the tower base, a3 is the ultrasonic detection probe, and a4 is the signal processing system; b is the magnetic particle detection method, b1 is the anchor bolt, b2 is the tower base, and b3 is the magnetic particle.
[0034] Figure 2 Schematic diagram of the anchor bolt corrosion detection system based on microwave detection in Example 1 of the present invention, in which 01 is a hardware segment, 011 is a transmitting antenna bracket, 012 is a transmitting antenna, 013 is a microwave generator, 014 is a receiving antenna bracket, 015 is a receiving antenna, 016 is a spectrum analyzer, a1 is an anchor bolt, a2 is a tower base, a3 is a corrosion area, a4 is the ground, 02 is a software end, 021 is a computer, and 022 is a cloud database.
[0035] Figure 3 Schematic diagram of the uncorroded model and the corroded model of the anchor bolt established in Example 1 of the present invention, in which a is the uncorroded model, a1 is the tower base, a2 is the transmitting antenna, a3 is the anchor bolt, a4 is the receiving antenna, b is the corroded model, b1 is the tower base, b2 is the transmitting antenna, b3 is the anchor bolt, b4 is the receiving antenna, b5 is the corrosion layer,
[0036] Figure 4 is S in Example 1 of the present invention 21 Comparison of amplitude versus frequency curves, where curve 1 and curve 2 are the detection results of the uncorroded model and the corroded model, respectively.
[0037] Figure 5 is S in Example 2 of the present invention 21 Comparison of amplitude versus frequency curves, where curve 1 and curve 2 are the detection results of the uncorroded model and the corroded model, respectively.
[0038] Figure 6 is S in Example 3 of the present invention 21 Comparison of amplitude versus frequency curves, where curve 1 and curve 2 are the detection results of the uncorroded model and the corroded model, respectively. DETAILED DESCRIPTION
[0039] Example 1
[0040] See also Figure 2Embodiment 1 of the present invention provides a microwave detection-based anchor bolt corrosion detection system, including a hardware end 01 and a software end 02, wherein the hardware end 01 includes a microwave generator 013, a transmitting antenna 012, a transmitting antenna bracket 011, a receiving antenna 015, a receiving antenna bracket 014, and a spectrum analyzer 016, and the software end 02 includes a computer 021 and a cloud database 022, the transmitting antenna 012 is fixed on the transmitting antenna bracket 011, the transmitting antenna 012 is connected to the microwave generator 013, the receiving antenna 015 is fixed on the receiving antenna bracket 014, and the receiving antenna 015 is connected to the spectrum analyzer 016, the anchor bolt transmission coefficient reference frequency domain spectrum obtained by the spectrum analyzer 016 is stored in the computer and uploaded to the cloud database, the anchor bolt transmission coefficient reference frequency domain spectrum is imported into the spectrum analyzer to obtain the anchor bolt transmission coefficient frequency domain spectrum to be tested, and the difference analysis can be performed by the computer.
[0041] The transmitting antenna support 011 and the receiving antenna support 014 are height-adjustable and can be bent within a range of -90 to 90 degrees.
[0042] The transmitting antenna 012 is connected to the microwave output port of the microwave generator 013 via a coaxial cable, and the receiving antenna 015 is connected to the signal input port of the spectrum analyzer 016 via a coaxial cable.
[0043] Embodiment 1 of the present invention provides, on the other hand, a method for detecting corrosion of anchor bolts based on microwave detection, comprising the following steps:
[0044] (1) According to the diameter of the anchor bolt to be tested, the microwave frequency band is determined based on the formula, and the transmitting antenna and the receiving antenna corresponding to the port size are selected according to the frequency band, so that the detection frequency band is included in the frequency range of the transmitting antenna and the receiving antenna;
[0045] (2) Fix the transmitting antenna to the transmitting antenna bracket through a clamp, and fix the receiving antenna to the receiving antenna bracket through a clamp;
[0046] (3) Connecting the receiving antenna bracket to the microwave output port of the microwave generator through a coaxial cable, connecting the transmitting antenna to the signal input port of the spectrum analyzer through a coaxial cable, the transmitting antenna emits a microwave signal, and the receiving wire receives the transmitted signal;
[0047] (4) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna to perform microwave detection on the uncorroded anchor bolts. The spectrum analyzer obtains the transmission wave frequency domain spectrum corresponding to each scanning point of the anchor bolts, which is stored in the computer as the reference frequency domain spectrum of the anchor bolt transmission coefficient and uploaded to the cloud database;
[0048] (5) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna, perform microwave detection on each scanning point of the anchor bolt to be tested, and use a spectrum analyzer to obtain a frequency domain spectrum of the transmission coefficient of the anchor bolt to be tested;
[0049] (6) Importing the anchor bolt transmission coefficient reference frequency domain spectrum into the anchor bolt transmission coefficient frequency domain spectrum to be tested, and performing frequency domain response difference analysis to obtain the test results. The test results are used to determine whether the anchor bolt is corroded, the severity of the corrosion, and the location of the corrosion point;
[0050] (7) Propose a repair or replacement plan for the anchor bolts based on the test results.
[0051] The uncorroded model of the anchor bolt (equivalent to the benchmark in the method) and the corroded model (equivalent to the anchor bolt to be tested in the method) are established by CST electromagnetic simulation software. Figure 3 The size of the concrete tower foundation (including the underground part) is 100×100×400mm. The anchor bolts are L-shaped bolts, placed in the center of the tower foundation, with a diameter of 12mm and a length of 500mm, of which 100mm is exposed outside the tower foundation, and the length of the L-shaped bent rod at the bottom is 50mm. The outer diameter of the nut is 24mm and the height is 10mm. The corrosion layer is 60mm long and 12mm thick, of which 6mm is embedded in the bolts and 6mm is expanded outward and embedded in the tower foundation. The corrosion layer (center position) is 100mm away from the top of the concrete tower foundation.
[0052] The formula is λ=πd, where λ is the microwave frequency band and d is the diameter of the anchor bolt to be measured.
[0053] Based on the formula, the detection frequency range is determined to be 4 to 6 GHz.
[0054] The transmitting antenna and the receiving antenna are both horn antennas, and the horn antenna is a pyramid double-ridge horn antenna. The transmitting antenna and the receiving antenna are oriented toward the corrosion layer (center position) of the anchor bolt to be measured at an angle R1 = 45°.
[0055] Each scanning point in the anchor bolt transmission coefficient benchmark frequency domain spectrum corresponds to each scanning point in the anchor bolt transmission coefficient frequency domain spectrum to be tested. After installation, the anchor screw is first tested to obtain the anchor bolt transmission coefficient benchmark frequency domain spectrum, which is uploaded to the cloud database. When a problem occurs in the anchor screw and needs to be tested, the matching anchor bolt transmission coefficient benchmark frequency domain spectrum is called out from the cloud database, and the transmitting antenna and the receiving antenna are adjusted according to the scanning points of the anchor bolt transmission coefficient benchmark frequency domain spectrum. The transmission coefficient benchmark frequency domain spectrum of the anchor bolt is obtained. The anchor bolt transmission coefficient benchmark frequency domain spectrum with the same scanning points is obtained. Subsequently, based on the comparison of the anchor bolt transmission coefficient benchmark frequency domain spectrum with the same scanning points and the anchor bolt transmission coefficient benchmark frequency domain spectrum, the frequency domain response difference analysis results are used to determine whether corrosion occurs, the severity of corrosion, and the corresponding corrosion point location.
[0056] The detection result of the comparative frequency domain response difference analysis is S 21 Amplitude vs. frequency curve comparison (see Figure 4 ), if S 21 In the comparison of amplitude vs. frequency curves, the curve to be tested shows an S curve relative to the reference curve. 21 The part with reduced amplitude is judged to be corrosion, and the reduced S 21 The significant decrease in amplitude of 5dB indicates that the corrosion level is serious, and a treatment plan is proposed based on the corrosion level.
[0057] The position of the corrosion point is determined based on the orientation angle of the transmitting antenna and the receiving antenna (45°), the lifting distance (100mm) and the antenna height (100mm), wherein the orientation angle of the transmitting antenna and the receiving antenna is the angle between the transmitting antenna or the receiving antenna and the line connecting the scanning point relative to the horizontal position, the lifting distance is the horizontal distance between the transmitting antenna or the receiving antenna and the edge of the anchor bolt, and the antenna height is the height of the transmitting antenna or the receiving antenna relative to the ground.
[0058] The cloud database includes anchor bolt transmission coefficient reference frequency domain spectra of anchor bolts with different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower foundation thicknesses, and anchor bolts in different environments;
[0059] The cloud database also includes the detection results of the frequency domain response difference analysis of the benchmark frequency domain spectra of the anchor bolt transmission coefficient and the frequency domain spectra of the anchor bolt transmission coefficient to be tested for different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower base thicknesses, and anchor bolts in different environments.
[0060] Example 2
[0061] Embodiment 2 of the present invention provides a foundation bolt corrosion detection system and detection method based on microwave detection. The specific implementation method is the same as that of Embodiment 1, except that the transmitting antenna and the receiving antenna are oriented toward the corrosion layer (center position) of the foundation bolt to be detected at an angle R1=30°, and the detection result of the comparative frequency domain response difference analysis is S 21 Amplitude vs. frequency curve comparison (see Figure 5 ).
[0062] Example 3
[0063] Embodiment 3 of the present invention provides a foundation bolt corrosion detection system and detection method based on microwave detection. The specific implementation method is the same as that of Embodiment 1, except that the transmitting antenna and the receiving antenna are oriented toward the corrosion layer (center position) of the foundation bolt to be detected at an angle R1=60°, and the detection result of the comparative frequency domain response difference analysis is S 21 Amplitude vs. frequency curve comparison (see Figure 6 ).
[0064] According to the above example, it can be explained that the optimal range of the angle R1 of the transmitting antenna and the receiving antenna toward the corrosion layer (center position) of the anchor bolt to be measured is 0°≤R1≤45°.
Claims
1. A foundation bolt corrosion detection system based on microwave detection, characterized in that: It includes a hardware end and a software end, wherein the hardware end includes at least a microwave generator, a transmitting antenna, a transmitting antenna bracket, a receiving antenna, a receiving antenna bracket, and a spectrum analyzer; the software end includes at least a computer and a cloud database; the transmitting antenna is fixed on the transmitting antenna bracket, which is connected to the microwave generator; the receiving antenna is fixed on the receiving antenna bracket, which is connected to the spectrum analyzer; the reference frequency domain spectrum of the anchor bolt transmission coefficient obtained by the spectrum analyzer is stored in the computer and uploaded to the cloud database; the reference frequency domain spectrum of the anchor bolt transmission coefficient is imported into the spectrum analyzer to obtain the frequency domain spectrum of the anchor bolt transmission coefficient to be tested, and corrosion detection can be achieved by performing difference analysis on the computer.
2. The anchor bolt corrosion detection system based on microwave detection according to claim 1 is characterized in that: The receiving antenna bracket and the transmitting antenna bracket are height-adjustable and can be bent within the range of -90 to 90 degrees.
3. The anchor bolt corrosion detection system based on microwave detection according to claim 2 is characterized in that: The transmitting antenna is connected to the microwave output port of the microwave generator through a coaxial cable, and the receiving antenna is connected to the signal input port of the spectrum analyzer through a coaxial cable.
4. A method for detecting corrosion of anchor bolts based on microwave detection, using the system according to any one of claims 1 to 3, characterized in that: At least the following steps are included: (1) According to the diameter of the anchor bolt to be tested, the microwave frequency band is determined based on the formula, and the transmitting antenna and the receiving antenna corresponding to the port size are selected according to the frequency band, so that the detection frequency band is included in the frequency range of the transmitting antenna and the receiving antenna; (2) Fix the transmitting antenna to the transmitting antenna bracket through a clamp, and fix the receiving antenna to the receiving antenna bracket through a clamp; (3) connecting the transmitting antenna to the microwave output port of the microwave generator through a coaxial cable, and connecting the receiving antenna to the signal input port of the spectrum analyzer through a coaxial cable, wherein the transmitting antenna emits a microwave signal and the receiving wire receives the transmitted signal; (4) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna to perform microwave detection on the uncorroded anchor bolts so that the spectrum analyzer can obtain the transmission wave frequency domain spectrum corresponding to each scanning point of the anchor bolts, which is stored in the computer as the reference frequency domain spectrum of the anchor bolt transmission coefficient and uploaded to the cloud database; (5) Adjust the orientation angle, lifting distance and antenna height of the transmitting antenna and the receiving antenna, perform microwave detection on each scanning point of the anchor bolt to be tested, and use a spectrum analyzer to obtain a frequency domain spectrum of the transmission coefficient of the anchor bolt to be tested; (6) Importing the anchor bolt transmission coefficient reference frequency domain spectrum into the anchor bolt transmission coefficient frequency domain spectrum to be tested, and performing frequency domain response difference analysis to obtain the test results. The test results are used to determine whether the anchor bolt is corroded, the severity of the corrosion, and the location of the corrosion point; (7) Propose a repair or replacement plan for the anchor bolts based on the test results.
5. The anchor bolt corrosion detection method based on microwave detection according to claim 4 is characterized in that: The formula is λ=πd, where λ is the microwave frequency band and d is the diameter of the anchor bolt to be measured.
6. The anchor bolt corrosion detection method based on microwave detection according to claim 5 is characterized in that: The transmitting antenna and the receiving antenna are both horn antennas, and the horn antenna is one of a sector horn antenna, a pyramid horn antenna, a conical horn antenna, a corrugated horn antenna, a ridged horn antenna, and a multi-mode horn antenna.
7. The anchor bolt corrosion detection method based on microwave detection according to claim 6 is characterized in that: The range of the angle R of the transmitting antenna and the receiving antenna toward the anchor bolt to be measured is -90°<R<90°.
8. The anchor bolt corrosion detection method based on microwave detection according to claim 7 is characterized in that: The range of the angle R1 of the transmitting antenna and the receiving antenna toward the center position of the corrosion layer of the anchor bolt to be measured is 0°<R1<90°.
9. The anchor bolt corrosion detection method based on microwave detection according to claim 8 is characterized in that: The cloud database includes anchor bolt transmission coefficient reference frequency domain spectra of anchor bolts with different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower base thicknesses, and anchor bolts in different environments.
10. The anchor bolt corrosion detection method based on microwave detection according to claim 9, characterized in that: The cloud database also includes the detection results of the comparative frequency domain response difference analysis of the anchor bolt transmission coefficient benchmark frequency domain spectra and the anchor bolt transmission coefficient frequency domain spectra to be tested for different lifting distances and antenna heights, different types of anchor bolts, different bolt burial depths, different tower base thicknesses, and anchor bolts in different environments.