A hybrid structure interface defect type inversion method

Abstract

The present application belongs to the technical field of electromagnetic nondestructive testing, and particularly relates to a mixed structure interface defect type inversion method. The mixed structure interface defect type inversion method realizes the fusion and complementation of low-frequency and high-frequency information by combining the detection information of low-frequency eddy current and high-frequency eddy current, and finally realizes the inversion of the mixed interface complex defect type. In the low-frequency line scanning result, whether there is distortion can be used to judge whether the conductive layer has defects, and the number of peak values of the detection signal and the half-peak width of the single-peak signal can be used to judge the type of the defects of the conductive layer; the combined detection result of the high-frequency line scanning result can be used to judge whether the insulating layer has defects. Therefore, the overall defect information in the mixed structure can be determined in time, which provides technical support for realizing the accurate repair of the mixed structure, preventing the further deterioration of the performance and durability of the mixed structure and causing major economic and life safety losses.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic nondestructive testing technology, and particularly relates to a method for inverting the type of defects at hybrid structure interfaces. Background Technology

[0002] With the gradual development of science and technology, technicians have placed higher demands on the quality, performance, and standards of materials. Single insulating or conductive structures can no longer meet practical needs, leading to the widespread development and application of hybrid structures with "insulation-conductor" hybrid characteristics. For example, CFRP (Carbon Fiber-reinforced Polymer) reinforced steel beam hybrid structures can be used to improve the structural performance of trusses; steel-concrete hybrid structures can be applied to high-rise buildings, long-span bridges, and other infrastructure; thermal barrier coatings can be used to cover gas turbine casings to increase engine operating temperatures. The aforementioned "insulation-conductivity" hybrid structures combine the corrosion resistance, high-temperature resistance, and wear resistance of insulating materials with the high strength and hardness of conductive metallic materials.

[0003] However, due to unfavorable conditions during manufacturing and use, the interface between the insulator and conductor in hybrid structures is easily damaged. Furthermore, harsh operating environments, improper curing of epoxy adhesives during installation, or concentrated stress accumulated during use can all cause debonding of the external adhesive layer of the "insulation-conductivity" hybrid structure. On this basis, cyclic loading, periodic temperatures, unscientific casting processes, and severe corrosive environments can further lead to interface defects in the "insulation-conductivity" hybrid structure. In addition, interface debonding, interface cracks, and interface corrosion can further deteriorate the performance and durability of the "insulation-conductivity" hybrid structure, all of which pose new challenges to its function and integrity. Simultaneously, the diversity of materials, the complexity of the structure, and the limitations of the field application environment also present new difficulties for the effective detection of interface defects and the accurate identification of complex defect types in "insulation-conductivity" hybrid structures.

[0004] Currently, non-destructive testing (NDT) technologies such as ultrasonic testing, acoustic emission testing, X-ray testing, and microwave imaging have been applied to the field of interface defect detection. However, these technologies often only detect single types of defects and cannot perform comprehensive NDT evaluation of hybrid "insulation-conductivity" structures, let alone distinguish and invert the defect types at the interface of the hybrid structure. Especially for complex situations such as conductor corrosion defects or cracks coexisting with insulation layer debonding defects, existing detection methods cannot accurately identify them, leading to a high risk of misjudgment; furthermore, the detection efficiency is relatively low, posing significant risks to the subsequent performance and safety of hybrid "insulation-conductivity" structures.

[0005] Therefore, it is necessary for those skilled in the art to propose a method that can effectively solve the problem of detecting complex defects in "insulation-conductivity" hybrid structures, thereby achieving the detection of defects in different material layers and the efficient and low-cost inversion determination of defect types. Summary of the Invention

[0006] This invention provides a method for inverting defect types at hybrid structural interfaces. This method combines detection information from low-frequency eddy currents and high-frequency eddy currents (capacitance) to achieve the fusion and complementarity of low-frequency and high-frequency information, ultimately enabling the inversion of complex defect types at hybrid interfaces. Specifically, low-frequency... The presence or absence of distortion in the line scan results can be used to determine the presence of defects in the conductive layer. The number of peak values ​​and the width at half-peak height of the detection signal, when combined, can be used to determine the type of defect in the conductive layer. Meanwhile, high-frequency... Line scan results combined The detection results can be used to determine the presence or absence of insulation layer defects. This hybrid structure interface defect type inversion method can accurately obtain defect type information of different material layers in the hybrid structure, and promptly determine the comprehensive defect information in the hybrid structure. This provides technical support for achieving precise repair of the hybrid structure and preventing further deterioration of the hybrid structure's performance and durability, thus avoiding significant economic and life safety losses.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A method for inverting the defect type of a hybrid structure interface includes the following steps:

[0009] S101: Scan and detect the parallel surfaces of the hybrid structure interface to obtain the excitation frequencies used to reflect the conductive layers in the hybrid structure. impedance response signal And the excitation frequency used to reflect the insulating layer in the hybrid structure is Impedance response signal ;

[0010] S102: For excitation frequency of impedance response signal Peak finding is performed on the corresponding scanning curve, and the found peak value is compared with... Compare with preset values;

[0011] If found If the peak value does not exceed the preset value, it is determined that there are no defects in the conductive layer of the hybrid structure; otherwise, it is determined that there are defects in the conductive layer of the hybrid structure.

[0012] S103: For excitation frequency of impedance response signal Perform integration on the corresponding scan curve;

[0013] If the absolute value of the integral obtained from the integration operation does not exceed If the preset value is met, it is determined that there are no defects in the insulation layer of the hybrid structure;

[0014] If the integral value obtained from the integration operation exceeds If the preset value is positive and the integral value is positive, then it is determined that there is a defect in the insulation layer in the hybrid structure;

[0015] If the integral value obtained from the integration operation exceeds If the preset value is not met and the integral value is negative, then it is determined that there is a defect in the conductive layer of the hybrid structure.

[0016] More preferably, step S102 further includes the following steps:

[0017] S1021: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ;

[0018] S1022: If If one remains, the defect signal of the conductive layer in the hybrid structure is determined to be a single peak, and the width at half the peak height of the defect signal is calculated.

[0019] If the width at half the peak height is greater than the diameter of the scanning sensor, the defect is determined to be a large-area corrosion defect; if the width at half the peak height is less than the diameter of the scanning sensor, the defect is determined to be a crack defect.

[0020] S1023: If If two remain, the defect signal of the conductive layer in the hybrid structure is determined to be bimodal, and a second scan is performed at the same location; the scanning direction of the second scan is perpendicular to the scanning direction of the first scan.

[0021] After the second scan is completed, the peaks of the scan curve corresponding to the second scan are searched and peaks are judged and eliminated again. If only one peak remains in the second scan result, the defect is determined to be a crack defect. If two peaks remain in the second scan result, the defect is determined to be a small area corrosion defect.

[0022] More preferably, step S103 further includes the following steps:

[0023] S1031: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... Impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ;

[0024] S1032: If If one remains, the defect type of the conductive layer in the hybrid structure is determined based on the judgment conclusion of step S1022.

[0025] S1033: If If two defects remain, the number and type of defects in the conductive layer of the hybrid structure are determined based on the conclusions of steps S1022 and S1023; and it is inferred whether there are defects in the insulating layer of the hybrid structure.

[0026] S1033: If Finally, 3 remain, indicating that there are defects in the insulating layer of the hybrid structure; based on the judgment conclusions of steps S1022 and S1023, the number and type of defects in the conductive layer of the hybrid structure are determined, and the number of defects in the insulating layer of the hybrid structure is inferred.

[0027] The preferred option is... The preset value is not greater than 1‰ of the benchmark value.

[0028] The preferred option is... The preset value is no greater than 5 units. 1‰ of the benchmark value.

[0029] This invention provides a method for inverting the defect type of a hybrid structure interface. This method includes: S101: scanning and detecting the parallel surfaces of the hybrid structure interface to obtain the excitation frequencies reflecting the insulating layer in the hybrid structure. impedance response signal And the excitation frequency used to reflect the conductive layer in the hybrid structure is Impedance response signal S102: For excitation frequency of impedance response signal Peak finding is performed on the corresponding scanning curve, and the found peak value is compared with... Compare with the preset value; if the peak value found does not exceed If the preset value is met, it is determined that the conductive layer in the hybrid structure is defect-free; otherwise, it is determined that the conductive layer in the hybrid structure has defects. S103: For excitation frequency of... impedance response signal Perform integration on the corresponding scanning curve; if the absolute value of the integral obtained from the integration does not exceed... If the preset value is met, the insulating layer in the hybrid structure is determined to be defect-free; if the integral value obtained from the integral calculation exceeds... If the integral value is positive and the preset value is met, then a defect is determined to exist in the insulation layer of the hybrid structure; if the integral value obtained from the integral calculation exceeds the preset value, then the defect is determined to exist in the insulation layer of the hybrid structure. If the preset value is found and the integral value is negative, then it is determined that there is a defect in the conductive layer of the hybrid structure. The hybrid structure interface defect type inversion method with the above-mentioned step characteristics has at least the following advantages compared to existing technologies;

[0030] (1) It can accurately invert complex types of defects in "insulation-conductivity" hybrid structures (such as conductor corrosion defects and conductor crack defects under insulation layer debonding defects), and can determine the presence or absence of insulation layer defects. This helps to accurately obtain the defect type information of different material layers in the hybrid structure, timely determine the comprehensive defect information in the hybrid structure, complete the accurate repair and replacement of the hybrid structure, prevent further deterioration of the performance and durability of the hybrid structure and cause significant economic and life safety losses, and does not require destroying the integrity of the hybrid structure sample.

[0031] (2) It has many applications, a wide range of targets, strong anti-interference ability, and reliable inversion results. When performing peak finding and judgment on the detection signal, the regular values ​​are summarized through multiple experiments, and interference noise peaks are eliminated, which greatly reduces the false judgment rate. The inversion results of specific embodiments show that this method has good robustness and reliability.

[0032] (3) The accurate inversion judgment results can greatly improve the accuracy of identifying complex types of defects in "insulation-conductivity" mixed structures and greatly reduce the detection cost, and have strong field applicability. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the following drawings:

[0034] Figure 1 A flowchart illustrating a hybrid structure interface defect type inversion method provided by the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a high-frequency eddy current (capacitance) - low-frequency eddy current dual-mode detection device used in this invention;

[0036] Figure 3 for Figure 2 A schematic diagram of the structure of the single-ended excitation (receiver) dual-mode detection sensor in the dual-mode detection device shown;

[0037] Figure 4 A schematic diagram of a hybrid structure sample of plexiglass (30mm diameter flat-bottomed round hole defect) and aluminum plate (10mm diameter flat-bottomed round hole defect) provided in an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of a hybrid structure sample of plexiglass (20mm diameter flat-bottomed round hole defect) and aluminum plate (10mm diameter flat-bottomed round hole defect) provided in an embodiment of the present invention;

[0039] Figure 6 A schematic diagram of a hybrid structure sample of plexiglass (20mm diameter flat-bottomed round hole defect) and aluminum plate (20mm length crack defect) provided in an embodiment of the present invention;

[0040] Figure 7 A schematic diagram of a hybrid structure sample of plexiglass (30mm diameter flat-bottomed round hole defect) and aluminum plate (20mm length crack defect) provided in an embodiment of the present invention;

[0041] Figure 8 for Figure 4 The dual-mode detection results of the hybrid structure are shown in the figure.

[0042] Figure 9 for Figure 4 The excitation frequency of the hybrid structure shown is impedance response signal Peak finding results of the corresponding scanning curve;

[0043] Figure 10 for Figure 4 The excitation frequency (vertical direction) of the hybrid structure shown is impedance response signal The result of the peak finding of the corresponding scanning curve;

[0044] Figure 11 for Figure 5 The dual-mode detection results of the hybrid structure are shown in the figure.

[0045] Figure 12 for Figure 5 The excitation frequency of the hybrid structure shown is impedance response signal Peak finding results of the corresponding scanning curve;

[0046] Figure 13 for Figure 5 The excitation frequency (vertical direction) of the hybrid structure shown is impedance response signal The result of the peak finding of the corresponding scanning curve;

[0047] Figure 14 for Figure 5 The excitation frequency of the hybrid structure shown is impedance response signal Peak finding results of the corresponding scanning curve;

[0048] Figure 15 for Figure 6 The dual-mode detection results of the hybrid structure are shown in the figure.

[0049] Figure 16 for Figure 6 The excitation frequency of the hybrid structure shown is impedance response signal Peak finding results of the corresponding scanning curve;

[0050] Figure 17 for Figure 6 The excitation frequency (vertical direction) of the hybrid structure shown is impedance response signal The result of the peak finding of the corresponding scanning curve;

[0051] Figure 18 for Figure 7 The dual-mode detection results of the hybrid structure are shown in the figure.

[0052] Figure 19 for Figure 7 The excitation frequency of the hybrid structure shown is impedance response signal Peak finding results of the corresponding scanning curve;

[0053] Reference numerals: 1. XYZ three-axis scanning stage; 2. Single-ended excitation (receiving) dual-mode detection sensor; 3. Test workpiece sample; 4. Impedance analyzer calibration device 42941A; 5. Impedance analyzer E4990A; 6. PC with pre-stored stage control program and impedance analyzer control program; 101. Single-plane helical coil sensor; 102. SMA coaxial cable interface. Detailed Implementation

[0054] This invention provides a method for inverting defect types at hybrid structural interfaces. This method combines detection information from low-frequency eddy currents and high-frequency eddy currents (capacitance) to achieve the fusion and complementarity of low-frequency and high-frequency information, ultimately enabling the inversion of complex defect types at hybrid interfaces. Specifically, low-frequency... The presence or absence of distortion in the line scan results can be used to determine the presence of defects in the conductive layer. The number of peak values ​​and the width at half-peak height of the detection signal, when combined, can be used to determine the type of defect in the conductive layer. Meanwhile, high-frequency... Line scan results combined The detection results can be used to determine the presence or absence of insulation layer defects. This hybrid structure interface defect type inversion method can accurately obtain defect type information of different material layers in the hybrid structure, and promptly determine the comprehensive defect information in the hybrid structure. This provides technical support for achieving precise repair of the hybrid structure and preventing further deterioration of the hybrid structure's performance and durability, thus avoiding significant economic and life safety losses.

[0055] This invention provides a method for inverting the defect type of a hybrid structure interface, such as... Figure 1 As shown, this method for inverting the interface defect type of a hybrid structure includes the following steps:

[0056] S101: Scan and detect the parallel surfaces of the hybrid structure interface to obtain the excitation frequencies used to reflect the conductive layers in the hybrid structure. impedance response signal And the excitation frequency used to reflect the insulating layer in the hybrid structure is Impedance response signal .

[0057] It is worth noting that, in order to ensure the accuracy of the scanning results of the inversion method provided by the present invention for scanning the parallel surface of the hybrid structure interface, the impedance analyzer is further self-calibrated and the surface to be tested of the structure to be tested is cleaned before the scanning detection step of the parallel surface of the hybrid structure interface.

[0058] Specifically, the instrument self-calibration process can be described as follows: performing instrument self-calibration on the impedance analyzer, connecting and checking each component in the instrument system, and correctly setting the operating parameters of the instrument system. Cleaning the surface of the structure to be tested aims to remove dust, impurities, and other contaminants that may affect the accuracy of the scanning results.

[0059] In addition, it should be noted that the excitation frequency used to reflect the conductive layer in the hybrid structure is... impedance response signal Specifically, this corresponds to a low-frequency eddy current detection mode; while the excitation frequency used to reflect the insulating layer in the hybrid structure is... Impedance response signal Specifically, it corresponds to a high-frequency eddy current (capacitance) detection mode.

[0060] To facilitate understanding of the technical solution of the hybrid structure interface defect type inversion method provided by this invention by those skilled in the art, the inventors further provide a detection device capable of realizing the above-mentioned high-frequency eddy current (capacitance) - low-frequency eddy current dual detection mode as a reference. Specifically, the structural principle schematic diagram of this dual-mode detection device is shown below. Figure 2 As shown, it includes a single-ended excitation (receiver) dual-mode detection sensor (such as...). Figure 3 The system includes an XYZ three-axis scanning stage, an E4990A impedance analyzer, a 42941A impedance analyzer calibration device, and a PC with pre-stored stage control and impedance analyzer control programs. The single-ended excitation (receiver) dual-mode detection probe further includes: a metal shielding shell, a substrate, a single-plane helical coil sensor, a backplane shielding layer structure, and an SMA coaxial cable connector. The planar helical coil (38mm in diameter) is etched onto the FR4 substrate using printed circuit board technology and connected to the impedance analyzer via a coaxial cable. The single-plane helical coil sensor serves as both the excitation and receiving coil; in capacitive mode, it functions like a parallel-plate capacitor, and in eddy current mode, it forms an electromagnetic coupling relationship with the conductor, such as... Figure 3 As shown.

[0061] Furthermore, to further verify the reliability of the hybrid structure interface defect type inversion method provided by this invention, the applicant hereby provides four hybrid structures (where the centers of insulating layer defects and conductor layer defects coincide) for complex defect type inversion, such as... Figure 4 , 5As shown in Figures 6 and 7, the four hybrid structures are: a hybrid structure of conductor layer corrosion (10mm diameter flat-bottomed round hole defect) under insulation layer debonding (30mm diameter flat-bottomed round hole defect), a hybrid structure of conductor layer corrosion (10mm diameter flat-bottomed round hole defect) under insulation layer debonding (20mm diameter flat-bottomed round hole defect), a hybrid structure of conductor layer crack (20mm long crack defect) under insulation layer debonding (20mm diameter flat-bottomed round hole defect), and a hybrid structure of conductor layer crack (10mm long crack defect) under insulation layer debonding (30mm diameter flat-bottomed round hole defect).

[0062] After completing step S101, proceed to step S102: for an excitation frequency of... impedance response signal Peak finding is performed on the corresponding scanning curve, and the found peak value is compared with... Compare with preset values;

[0063] If the peak value found does not exceed If the preset value is met, it is determined that there are no defects in the conductive layer of the hybrid structure; otherwise, it is determined that there are defects in the conductive layer of the hybrid structure.

[0064] Furthermore, in a more preferred embodiment, step S102 further includes the following steps:

[0065] S1021: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ;

[0066] S1022: If If one remains, the defect signal of the conductive layer in the hybrid structure is determined to be a single peak, and the width at half the peak height of the defect signal is calculated.

[0067] If the width at half the peak height is greater than the diameter of the scanning sensor, the defect is determined to be a large-area corrosion defect; if the width at half the peak height is less than the diameter of the scanning sensor, the defect is determined to be a crack defect.

[0068] S1023: If If two remain, the defect signal of the conductive layer in the hybrid structure is determined to be bimodal, and a second scan is performed at the same location; the scanning direction of the second scan is perpendicular to the scanning direction of the first scan.

[0069] After the second scan is completed, the peaks of the scan curve corresponding to the second scan are searched and peaks are judged and eliminated again. If only one peak remains in the second scan result, the defect is determined to be a crack defect. If two peaks remain in the second scan result, the defect is determined to be a small area corrosion defect.

[0070] One preferred embodiment of the present invention is described below. The preset value is selected as not greater than 1‰ of the benchmark value.

[0071] It is worth noting that, as Figure 4 , 5 The four hybrid structures shown in Figures 6 and 7 for inversion of complex defect types, after being combined with the above steps and preset thresholds for discrimination, yield the following results: Figure 9 , 12 As shown in Figures 16 and 19.

[0072] In a specific embodiment, Figure 19 As shown Figure 7 Impedance response signal of a hybrid structure with conductor layer crack (10mm long crack defect) under insulation layer debonding (30mm diameter flat-bottomed round hole defect) The peak finding results of the corresponding scanning curve. Among them, after removing interfering peaks, one peak remains, as shown... Figure 19 As shown, its half-width at half-maximum (WHM) is smaller than that of the scanning sensor (39 mm). Therefore, it can be determined that... Figure 7 The conductive layer of the hybrid structure has crack defects (no need to re-scan the results in the vertical direction).

[0073] and Figure 9 , 12 The figures shown in 16 correspond to the following respectively: Figure 4 , 5 Impedance response signals of a mixed structure with three different defect types (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 ... The peak finding results of the corresponding scanning curves are shown in the figure. All peak finding results are bimodal. Then, a second detection and peak finding is performed perpendicular to the previous scanning direction, and the results are as follows. Figure 10 , 13 As shown in Figure 17, the results of the second vertical scan peak finding detection were, in sequence, two peaks, two peaks, and a single peak. Therefore, it can be determined that... Figure 4 and Figure 5 The conductive layers in the hybrid structure all exhibit small-area corrosion defects. Figure 6 The conductive layer of the hybrid structure has crack defects.

[0074] After completing step S102, proceed to step S103: for an excitation frequency of... impedance response signal Perform integration on the corresponding scan curve;

[0075] If the absolute value of the integral obtained from the integration operation does not exceed If the preset value is met, it is determined that there are no defects in the insulation layer of the hybrid structure;

[0076] If the integral value obtained from the integration operation exceeds If the preset value is positive and the integral value is positive, then it is determined that there is a defect in the insulation layer in the hybrid structure;

[0077] If the integral value obtained from the integration operation exceeds If the preset value is not met and the integral value is negative, then it is determined that there is a defect in the conductive layer of the hybrid structure.

[0078] In a preferred embodiment of the present invention, step S103 further includes the following steps:

[0079] S1031: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... Impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ;

[0080] S1032: If If one remains, the defect type of the conductive layer in the hybrid structure is determined based on the judgment conclusion of step S1022.

[0081] S1033: If If two defects remain, the number and type of defects in the conductive layer of the hybrid structure are determined based on the conclusions of steps S1022 and S1023; and it is inferred whether there are defects in the insulating layer of the hybrid structure.

[0082] S1033: If Finally, 3 remain, indicating that there are defects in the insulating layer of the hybrid structure; based on the judgment conclusions of steps S1022 and S1023, the number and type of defects in the conductive layer of the hybrid structure are determined, and the number of defects in the insulating layer of the hybrid structure is inferred.

[0083] Among the selectable ones, The preset value is no greater than 5 units. 1‰ of the benchmark value.

[0084] It should be noted that the excitation frequency used to reflect the conductive layer in the hybrid structure is... Impedance response signal Its direction (specifically downwards) is the same as the excitation frequency used to reflect the insulating layer in the hybrid structure. impedance response signal Their directions (specifically upwards) are opposite. Therefore, the integral value can be used to further determine whether there are defects in the insulation layer.

[0085] Specifically, in particular, Figure 4 , Figure 6 and Figure 7 Impedance response signals of mixed structures with different defect types If the integral of the scanning curve is positive, then it can be determined that... Figure 4 , 6 The insulating layer in the hybrid structure of 7 has defects.

[0086] And for such Figure 5 The impedance response signal of the hybrid structure shown The integral of the scanning curve is negative, and further, the excitation frequency is... Impedance response signal The peak value found in its scanning curve is used for judgment, and finally obtained The remaining 3, that is, Figure 15 As shown. At this point, it can be determined that... Figure 5 The hybrid structure shown contains defects in the insulating layer; further, by combining the peak-finding results of the conductive layer from the aforementioned steps, a comprehensive judgment can be made. Figure 5 Small-area corrosion defects exist in the conductive layer of the hybrid structure.

[0087] This completes the entire inversion process of the hybrid structure interface defect type inversion method provided by the present invention. The above discussion further confirms that the present invention can realize the inversion determination of the complex defect types of the four hybrid structures provided above.

[0088] This invention provides a method for inverting the defect type of a hybrid structure interface. This method includes: S101: scanning and detecting the parallel surfaces of the hybrid structure interface to obtain the excitation frequencies reflecting the insulating layer in the hybrid structure. impedance response signal And the excitation frequency used to reflect the conductive layer in the hybrid structure is Impedance response signal S102: For excitation frequency of impedance response signal The corresponding scanning curve is used to find peaks, and the peaks found are... Compare the peak value with the preset value; if found If the peak value does not exceed the preset value, it is determined that there are no defects in the conductive layer of the hybrid structure; otherwise, it is determined that there are defects in the conductive layer of the hybrid structure; S103: For excitation frequency of impedance response signal Perform integration on the corresponding scanning curve; if the absolute value of the integral obtained from the integration does not exceed... If the preset value is met, the insulating layer in the hybrid structure is determined to be defect-free; if the integral value obtained from the integral calculation exceeds... If the integral value is positive and the preset value is met, then a defect is determined to exist in the insulation layer of the hybrid structure; if the integral value obtained from the integral calculation exceeds the preset value, then the defect is determined to exist in the insulation layer of the hybrid structure. If the preset value is found and the integral value is negative, then it is determined that there is a defect in the conductive layer of the hybrid structure. The hybrid structure interface defect type inversion method with the above-mentioned step characteristics has at least the following advantages compared to existing technologies;

[0089] (1) It can accurately invert complex types of defects in "insulation-conductivity" hybrid structures (such as conductor corrosion defects and conductor crack defects under insulation layer debonding defects), and can determine the presence or absence of insulation layer defects. This helps to accurately obtain the defect type information of different material layers in the hybrid structure, timely determine the comprehensive defect information in the hybrid structure, complete the accurate repair and replacement of the hybrid structure, prevent further deterioration of the performance and durability of the hybrid structure and cause significant economic and life safety losses, and does not require destroying the integrity of the hybrid structure sample.

[0090] (2) It has many applications, a wide range of targets, strong anti-interference ability, and reliable inversion results. When performing peak finding and judgment on the detection signal, the regular values ​​are summarized through multiple experiments, and interference noise peaks are eliminated, which greatly reduces the false judgment rate. The inversion results of specific embodiments show that this method has good robustness and reliability.

[0091] (3) The accurate inversion judgment results can greatly improve the accuracy of identifying complex types of defects in "insulation-conductivity" mixed structures and greatly reduce the detection cost, and have strong field applicability.

[0092] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for inverting the defect type of a hybrid structure interface, characterized in that, The steps include the following: S101: Scan and detect the parallel surfaces of the hybrid structure interface to obtain the excitation frequencies used to reflect the conductive layers in the hybrid structure. impedance response signal And the excitation frequency used to reflect the insulating layer in the hybrid structure is Impedance response signal ; S102: For excitation frequency of impedance response signal Peak finding is performed on the corresponding scanning curve, and the found peak value is compared with... Compare with preset values; If the peak value found does not exceed If the preset value is met, it is determined that there are no defects in the conductive layer of the hybrid structure; Otherwise, it is determined that there is a defect in the conductive layer of the hybrid structure; S103: For excitation frequency of impedance response signal Perform integration on the corresponding scan curve; If the absolute value of the integral obtained from the integration operation does not exceed If the preset value is met, it is determined that there are no defects in the insulation layer of the hybrid structure; If the integral value obtained from the integration operation exceeds If the preset value is positive and the integral value is positive, then it is determined that there is a defect in the insulation layer in the hybrid structure; If the integral value obtained from the integration operation exceeds If the preset value is not met and the integral value is negative, then it is determined that there is a defect in the conductive layer of the hybrid structure; Step S102 also includes the following steps: S1021: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ; S1022: If If one remains, the defect signal of the conductive layer in the hybrid structure is determined to be a single peak, and the width at half the peak height of the defect signal is calculated. If the width at half the peak height is greater than the diameter of the scanning sensor, the defect is determined to be a large-area corrosion defect; if the width at half the peak height is less than the diameter of the scanning sensor, the defect is determined to be a crack defect. S1023: If If two remain, the defect signal of the conductive layer in the hybrid structure is determined to be bimodal, and a second scan is performed at the same location; the scanning direction of the second scan is perpendicular to the scanning direction of the first scan. After the second scan is completed, the peaks of the scan curve corresponding to the second scan are searched and peaks are judged and eliminated again. If only one peak remains in the second scan result, the defect is determined to be a crack defect. If two peaks remain in the second scan result, the defect is determined to be a small area corrosion defect. Step S103 also includes the following steps: S1031: When it is determined that there are defects in the conductive layer of the hybrid structure, the excitation frequency is... Impedance response signal The peak value found in the corresponding scan curve is used for judgment: if the found peak value satisfies Then remove Where i = 1, 2, ..., n; ; S1032: If If one remains, the defect type of the conductive layer in the hybrid structure is determined based on the judgment conclusion of step S1022. S1033: If If two defects remain, the number and type of defects in the conductive layer of the hybrid structure are determined based on the conclusions of steps S1022 and S1023; and it is inferred whether there are defects in the insulating layer of the hybrid structure. S1033: If Finally, 3 remain, indicating that there are defects in the insulating layer of the hybrid structure; based on the judgment conclusions of steps S1022 and S1023, the number and type of defects in the conductive layer of the hybrid structure are determined, and the number of defects in the insulating layer of the hybrid structure is inferred.

2. The method for inverting the defect type of a hybrid structure interface according to claim 1, characterized in that, The preset value is not greater than 1‰ of the benchmark value.

3. The method for inverting the defect type of a hybrid structure interface according to claim 1, characterized in that, The preset value is no greater than 5 units. 1‰ of the benchmark value.

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