Method for detecting material inhomogeneity by electromagnetic acoustic transmission and detection device therefor

Abstract

The application discloses a detection method and a detection device for detecting non-uniformity of electromagnetic acoustic transmission of a material, and is used for nondestructive detection of a nonmetallic, weakly conductive and weakly magnetically conductive composite material, especially a composite material with a honeycomb layer in the middle layer, such as uniformity detection and evaluation of an aluminum alloy composite plate used in aerospace. The application obtains detection signals from three aspects of electricity, magnetism and sound, and comprehensively analyzes and processes the detection signals (for example, extracting characteristic quantities related to material performance by using a spectrum analysis method on acoustic and electromagnetic signals), so as to obtain an evaluation and analysis conclusion on the uniformity of the composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing, in particular to the nondestructive testing technology of composite material plate, and more particularly to a detection method for detecting material non-uniformity by electromagnetic acoustic transmission and a detection device thereof. BACKGROUND

[0002] The development of modern science and technology has given rise to the invention of various composite materials. Among them, the inter-combination technology of metal and non-metal, conductive metal and weak conductive metal, non-conductive metal material, and flexible and non-flexible material is emerging in an endless stream, especially in the field of aerospace, there are various types of materials that are resistant to high temperature, high speed, high pressure and light in weight. For these emerging composite materials, how to judge their performance, especially the performance evaluation of finished products or in-situ parts, is one of the tasks of nondestructive testing workers at present. Although destructive testing is essential, non-destructive testing (i.e. non-destructive testing NDT) is more important. Non-destructive testing has great significance for the development of modern industry and modern science and technology. In view of the current composite material detection, such as aerospace composite material, in order to reduce weight, honeycomb is mostly used. NDT mostly uses ray method or ultrasonic method. The former cannot detect the quality of the adhesive layer, and the latter cannot effectively detect many composite materials due to the problem of material sound transmission.

[0003] In view of the above shortcomings, the present application adopts the following technical scheme. SUMMARY

[0004] The purpose of the present application is to provide a detection method for detecting material non-uniformity by electromagnetic acoustic transmission and a detection device thereof. The technical scheme disclosed is as follows:

[0005] A detection method for detecting material non-uniformity by electromagnetic acoustic transmission, which is used for non-destructive testing of non-metallic, weakly conductive, weakly magnetic composite materials, especially composite materials with honeycomb layers in the middle layer, such as the uniformity detection and evaluation of aluminum alloy composite plates used in aerospace. Its characteristics are that the acoustic vibration emission and acoustic vibration receiving probes are arranged opposite to the two surfaces of the composite plate to be detected, and the method of moving scanning on the two surfaces of the detected metal is used, and the magnetic detection probes are arranged on the two surfaces of the detected metal to detect the surface of the detected composite plate, and the acoustic method and alternating current magnetic field transmission method are combined to detect and comprehensively evaluate the uniformity of the composite material. The specific method steps are as follows:

[0006] a. Detection device configuration: the emission and receiving detection probes of the detection device are respectively attached to the two opposite detection surfaces of the composite plate to be detected, forming a moving scanning detection for clamping the composite material to be detected;

[0007] b. Actual detection: during the scanning process, the acoustic detection device emits an acoustic signal from the transmitting probe, which is directed through the inside of the composite material plate, and is received by the acoustic receiving probe on the opposite side to form a detection signal, at the same time, the electromagnetic detection device detects the two detection panels of the composite plate respectively, and forms a detection state that is directly opposite to the clamped composite plate for scanning detection;

[0008] c. Detection signal extraction image reconstruction: the detection instrument receives the detection signal for data image analysis;

[0009] d. Comprehensive defect analysis: the detection signal data of the acoustic detection device is mainly used for analyzing the middle layer of the detected composite material, at the same time of detection, the acoustic vibration signal affects the stress of the joint of the composite plate, and the magnetic detection is carried out, the detection data at the same time is fused and analyzed, and the uniformity defect problem of the composite material is judged.

[0010] Acoustic vibration detection is a non-destructive testing method for exciting the detected part to produce mechanical vibration, generating mechanical sound waves due to the elastic deformation of the detected part, and judging the quality by measuring the acoustic wave signal characteristics of the detected part vibration. Therefore, when the detected composite material produces elastic vibration (recoverable elastic deformation), the elastic stress of the composite material has a certain change, which has a certain influence on the magnetic characteristics of the material, especially the connecting layer part of the composite material, therefore, at the same time of acoustic vibration detection, magnetic detection of the composite material is carried out, that is, under the condition of mechanical acoustic vibration of the composite material, one or both of electromagnetic eddy current detection and magnetic flux leakage detection, which can better reflect the bonding condition of the material and make more accurate evaluation. The magnetic detection device used in the present application is an electromagnetic eddy current detection and magnetic flux leakage detection. In one embodiment, the eddy current and magnetic flux leakage probe can be integrated, and the spatial positioning technology is realized by using a code disc in physical principle, so as to fuse and evaluate the three kinds of information of a certain position of the detected composite material, especially the specific comprehensive detection information of the pore center position of the middle layer of the aluminum alloy honeycomb composite material used in aviation.

[0011] Further, the detection signal extraction is to extract the information data of the acoustic vibration detection device just detecting the hollow position of the middle layer of the composite material. The propagation of acoustic wave in the composite material is quite related to the hollow structure characteristics of the material, such as the echo of the sound, the generated acoustic wave is different in different structure space and different space angle. The present application selects and extracts the acoustic detection information of the acoustic vibration detection at the central position of the hollow position of the honeycomb composite material, which not only makes the generated acoustic wave signal more regular and obvious, but also facilitates continuous scanning detection, detection image reconstruction, and formation of regular detection image, so as to facilitate image analysis.

[0012] Further, the intermediate layer hollow position information data is the detection data of the regularity intermediate layer hollow geometry center position for sound signal detection analysis. The aluminum alloy honeycomb composite material used in aviation has regular hexagonal center voids, each hexagonal void periphery is connected as a barrier wall of adjacent voids, and the end of the barrier wall is connected to the outer aluminum alloy plate surface for fixation. Therefore, when the detection device moves for continuous detection, the detection information of the hexagonal honeycomb structure void center position can be regularly extracted. Further, the sound detection device extracts the intermediate layer hollow position detection signal, and the magnetic detection device extracts the joint position detection signal at the same time, forming a complete fusion detection of the sound detection and magnetic detection, and a detection evaluation analysis method.

[0013] Further, the sound detection and magnetic detection devices are arranged in an array, and the continuous scanning detection of the multiple detection devices extracts continuous multiple same hollow part and joint part detection signal data for analysis and evaluation and composite material uniformity determination. Due to the regularity structure characteristics of the honeycomb composite material, multiple same detection probes can be arranged according to the void structure, and the spacing of the multiple detection probes can be adjusted to adapt to the hollow gap distance of the honeycomb composite material. The spacing between the detection probes can be adjusted through multiple detection signal characteristics. That is, the detection method of the present application also includes detection verification and adjustment of the spacing between the detection probes before detection.

[0014] The application also discloses a detection device for detecting the non-uniformity of an electromagnetic acoustic transmission material, which is used for nondestructive testing of a nonmetallic, weakly conductive and weakly magnetically conductive composite material (1), especially a composite material with a honeycomb layer (12) in the middle layer of a double-layer metal plate (11), and is used for evaluating the uniformity of a honeycomb aluminum alloy composite plate (1) used in aerospace. The detection device (2) comprises an acoustic vibration detection device (23) and a magnetic detection device (24), characterized in that the detection device further comprises a first detection probe (2a) and a second detection probe (2b), a first detection plate (21) and a second detection plate (22), the first detection probe (2a) and the second detection probe (2b) are arranged on the first detection plate (21) and the second detection plate (22) arranged in parallel and opposite to each other, the acoustic emission probe (231) and the acoustic receiving probe (232) of the acoustic vibration detection device (23) are arranged opposite to each other on the first detection plate (21) and the second detection plate (22), respectively, and the first magnetic detection coil (241) and the second magnetic detection coil (242) of the magnetic detection device are arranged around the acoustic emission probe (231) and the acoustic receiving probe (232), respectively. The detection device is arranged in a symmetrical opposite manner and is suitable for the method of opposite acoustic detection of the honeycomb composite material. In one embodiment, the structure of the integrated eddy current and magnetic flux leakage probe is arranged around the acoustic vibration detection probe at the center position of the detection probe, and a layer of eddy current detection sensor coil and a layer of magnetic flux leakage detection sensor coil are arranged around the acoustic vibration detection probe at the center position of the detection probe. The two first detection probes and the second detection probes are designed to have a shell made of permanent magnet material and are electrically connected to the detection instrument.

[0015] Further, the acoustic emission probe (231) and the acoustic receiving probe (232) are respectively provided with the same magnetic detection device, and the first magnetic detection coil (241) and the second magnetic detection coil (242) of the same magnetic detection device are arranged around the acoustic emission probe (231) and the acoustic receiving probe (232).

[0016] Further, guide rails are arranged on the two detection plates of the detection device to slidably fix and adjust the positions of the first detection probe (2a) and the second detection probe (2b) and the first detection plate (21) and the second detection plate (22). By sliding to adjust the opposite positions of the first detection probe (2a) and the second detection probe (2b), the acoustic emission probe (231) and the acoustic receiving probe (232) of the acoustic vibration detection device can be adjusted to be just opposite to the hollow position in the middle layer of the composite material, such as the center position of the hexagonal hollow of the aluminum alloy honeycomb composite material. The detection signal of the acoustic detection device is extracted to correspond to the information data of the center position of the hollow of the composite material in the moving scanning detection; at the same time, the magnetic detection device just extracts the detection signal of the joint position.

[0017] Further, the detection device of the present application is an array type detection sensor structure of multiple detection probes, including multiple pairs of first detection probes (2a) and second detection probes (2b) arranged in an array on a first detection plate (21) and a second detection plate (22).

[0018] Further, the multiple pairs of first detection probes (2a) and second detection probes (2b) arranged in an array are adjusted in spacing on the first detection plate (21) and the second detection plate (22) by the guide rails. When the spacing of the multiple pairs of first detection probes (2a) and second detection probes (2b) arranged in an array is adjusted, the sound emission and sound reception of each pair of probes are just regularly and orthogonally arranged in spacing with the center of the honeycomb hollow of the aluminum honeycomb composite plate. During the moving scanning detection process, the detection data orthogonally arranged in spacing with the center of the honeycomb hollow are extracted for uniformity analysis and evaluation.

[0019] According to the above technical solution, the present application has the following beneficial effects: The present application is aimed at the problems in the background art, especially the non-destructive testing of non-metallic, weakly magnetic and conductive composite materials (such as carbon fibers, etc.), especially the honeycomb composite material structure. The transmission method of electricity, magnetism and sound is adopted to obtain the detection signals of the three for comprehensive analysis and processing (such as extracting the characteristic quantities related to the performance of the material by using frequency spectrum analysis means for the acoustic and electromagnetic signals), so as to obtain the evaluation and analysis conclusion of the uniformity of the composite material. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The detection device of the best embodiment of the present application is used in the state of the schematic diagram.

[0021] Figure 2 The structure of the detected object of the best embodiment of the present application is shown in the schematic diagram.

[0022] Figure 3 The structure of the detection device of the best embodiment of the present application is shown in the schematic diagram.

[0023] Figure 4 The principle of the detection method of the best embodiment of the present application is shown in the schematic diagram.

[0024] Figure 5 The principle of the detection method of the best embodiment of the present application is shown in the schematic diagram.

[0025] Figure 6 The structure of the detection device of the best embodiment of the present application is shown in the schematic diagram.

[0026] Figure 7 The structure of another embodiment of the detection device of the best embodiment of the present application is shown in the schematic diagram.

[0027] Figure 8 Another embodiment of the detection device of the best embodiment of the present application detects the use of a schematic diagram;

[0028] Figure 9 Another embodiment of the detection device of the best embodiment of the present application detects the principle of a schematic diagram. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the drawings and specific embodiments.

[0030] As Figure 1 and Figure 9 The present application relates to a method for detecting the uniformity of a composite material, and more particularly to a non-destructive testing method for non-metallic, weakly conductive, and weakly magnetic composite materials, especially those with honeycomb layers in the middle layer, such as the uniformity detection and evaluation of aluminum alloy composite plates used in aerospace. The method involves using acoustic vibration emitting and receiving probes arranged opposite to the two surfaces of the composite plate being tested, moving the probes across the two surfaces of the tested metal, and simultaneously using magnetic detection probes to detect the two surfaces of the composite plate being tested. The method combines acoustic and alternating current magnetic field transmission methods to simultaneously detect and comprehensively evaluate the uniformity of the composite material. The specific steps are as follows:

[0031] a. Detection device configuration: The emitting and receiving detection probes of the detection device are attached to the two opposite detection surfaces of the composite plate being tested, forming a moving scanning detection that clamps the composite material being tested;

[0032] b. Actual detection: During the scanning process, the emitting probe of the acoustic detection device emits an acoustic signal that passes through the interior of the composite material plate, and the receiving probe on the opposite side receives the detection signal. At the same time, the electromagnetic detection device detects the two detection surfaces of the composite plate, forming a scanning detection state that clamps the composite plate being tested;

[0033] c. Detection signal extraction image reconstruction: The detection instrument receives the detection signal for data image analysis;

[0034] d. Comprehensive defect analysis: The detection signal data of the acoustic detection device is mainly used to analyze the middle layer of the composite material being tested. At the same time, the acoustic vibration signal affects the stress at the joint of the composite plate, and the magnetic detection is carried out. The detection data at the same time is fused and analyzed to determine the uniformity defect of the composite material.

[0035] As Figure 4As shown in the figure, the acoustic vibration detection is a non-destructive testing method that excites the detected part to produce mechanical vibration, produces mechanical sound wave due to the elastic deformation of the detected part, and judges the quality by measuring the acoustic signal characteristics of the detected part. Therefore, the composite material produces elastic vibration (recoverable elastic deformation), the elastic stress of the composite material has certain changes, and the magnetic characteristics of the material are affected, especially the connecting layer part of the composite material. Therefore, while the acoustic vibration detection is being performed, the magnetic detection of the composite material is also being performed, that is, the magnetic detection, electromagnetic eddy current detection or magnetic flux leakage detection is performed under the condition of mechanical sound wave vibration of the composite material, which can better reflect the bonding condition of the material and make more accurate evaluation. The magnetic detection device used in the present application simultaneously performs electromagnetic eddy current detection and magnetic flux leakage detection. In one embodiment, the eddy current and magnetic flux leakage probes can be integrated, and the spatial positioning technology is realized by using a coded disc in the physical principle. The three kinds of information of the corresponding position of the detected composite material are fused and evaluated, especially the specific comprehensive detection information of the center position of the intermediate layer of the aluminum alloy honeycomb composite material used in aviation.

[0036] As shown in the figure, Figure 4 The detection signal extraction is to extract the information data of the acoustic vibration detection device detecting the center position of the intermediate layer of the composite material. The propagation of sound wave in the composite material is greatly related to the hollow structure characteristics of the material. For example, the echo produced by the sound is different at different structural spaces and different space angles. The present application selects the acoustic detection information of the center position of the hollow position of the honeycomb composite material by acoustic vibration detection. The generated acoustic signal is more regular and obvious, which is convenient for continuous scanning detection, reconstruction of detection image and formation of regular detection image, thereby facilitating image analysis.

[0037] As shown in the figure, Figure 2 and Figure 4 The intermediate layer hollow position information data is to extract the detection data of the center position of the regular intermediate layer hollow geometry for acoustic signal detection analysis. The center gap of the aluminum alloy honeycomb composite material used in aviation is a regular hexagon. The periphery of each hexagonal gap is connected as a barrier wall of adjacent gaps, and the end of the barrier wall is connected to the outer aluminum alloy plate surface to be fixed. Therefore, when the detection device moves for continuous scanning detection, the detection information of the center position of the hexagonal honeycomb structure gap can be regularly extracted. Moreover, the acoustic detection device extracts the intermediate layer hollow position detection signal, and the magnetic detection device extracts the joint part detection signal at the same time, thereby forming a complete fusion detection and detection evaluation analysis method of acoustic detection and magnetic detection.

[0038] As shown in the figure, Figures 7 to 9As shown, the acoustic detection and magnetic detection devices are arranged in an array, and the multiple detection devices continuously scan and detect to extract continuous detection signal data of multiple same hollow parts and joint parts for analysis, evaluation and composite material uniformity determination. Due to the regular structural characteristics of the honeycomb composite material, multiple same detection probes can be arranged according to the gap structure, and the spacing of the multiple detection probes can be adjusted to adapt to the hollow gap distance of the honeycomb composite material. The spacing between the detection probes before detection can be detected, verified and adjusted in the detection method of the present application.

[0039] The present application also discloses a detection device for detecting the uniformity of electromagnetic acoustic transmission of a material, which is used for non-destructive testing of a non-metal, weakly conductive and weakly magnetic composite material 1, especially a composite material with a honeycomb layer 12 in the middle layer of a double-layer metal plate 11, such as the uniformity detection and evaluation of a honeycomb aluminum alloy composite plate 1 used in aerospace. The detection device 2 comprises an acoustic vibration detection device 23, a magnetic detection device 24, a first detection probe 2a and a second detection probe 2b, a first detection plate 21 and a second detection plate 22, the first detection probe 2a and the second detection probe 2b are respectively arranged on the first detection plate 21 and the second detection plate 22 arranged in parallel and opposite to each other, the acoustic emission probe 231 and the acoustic receiving probe 232 of the acoustic vibration detection device 23 are respectively arranged opposite to the first detection plate 21 and the second detection plate 22, and the first magnetic detection coil 241 and the second magnetic detection coil 242 of the magnetic detection device are respectively arranged around the acoustic emission probe 231 and the acoustic receiving probe 232. The detection device is arranged in opposite symmetry, which is suitable for the method of opposite acoustic detection of the honeycomb composite material. As shown in Figure 6 In one embodiment, the structure of the integrated eddy current and magnetic flux leakage probe is arranged around the acoustic vibration detection probe at the center position of the detection probe, and a layer of eddy current detection sensor coil and a layer of magnetic flux leakage detection sensor coil are arranged around the acoustic emission probe 231 and the acoustic receiving probe 232. The two first detection probes and the second detection probes are designed to have a shell of permanent magnet material and are respectively electrically connected to the detection instrument.

[0040] As shown in Figure 6 The acoustic emission probe 231 and the acoustic receiving probe 232 are respectively provided with the same magnetic detection device, and the first magnetic detection coil 241 and the second magnetic detection coil 242 of the same magnetic detection device are arranged around the acoustic emission probe 231 and the acoustic receiving probe 232.

[0041] As shown in Figure 3 and Figure 4As shown in the figure, the guide rails are arranged on the two detection plates of the detection device to slidably fix and adjust the first detection probe 2a and the second detection probe 2b, so as to adjust the positions of the first detection plate 21 and the second detection plate 22. By slidingly adjusting the first detection probe 2a and the second detection probe 2b to be opposite to each other, the acoustic emission probe 231 and the acoustic receiving probe 232 of the acoustic vibration detection device are adjusted to be opposite to the hollow position in the middle layer of the composite material, such as the center position of the hexagonal hollow of the aluminum alloy honeycomb composite material. The detection signal of the acoustic detection device is extracted to be opposite to the information data of the center position of the hollow of the composite material in the mobile scanning detection; meanwhile, the magnetic detection device just extracts the detection signal of the joint position.

[0042] The detection device of the present application is an array type detection sensor structure of a plurality of detection probes, such as Figures 7 to 9 As shown in the figure, a plurality of pairs of first detection probes 2a and second detection probes 2b arranged opposite to each other are arranged on the first detection plate 21 and the second detection plate 22.

[0043] As shown in the figure, a plurality of pairs of first detection probes 2a and second detection probes 2b arranged opposite to each other are arranged on the first detection plate 21 and the second detection plate 22. Figure 8 and Figure 9 As shown in the figure, a plurality of pairs of first detection probes 2a and second detection probes 2b arranged opposite to each other are arranged on the first detection plate 21 and the second detection plate 22.

[0044] The above is one of the embodiments of the present application. In addition, it should be noted that any equivalent or simple changes made according to the structure, features and principles of the present application are included in the protection scope of the present application.

Claims

1. A method of detecting inhomogeneity of a material by electromagnetic acoustic transmittance, characterized by The method comprises the following steps: a. detection device configuration: the emission and receiving detection probes of the detection device are respectively attached to the two opposite detection surfaces of the detected composite board, forming a mobile scanning detection of the sandwiched detected composite material; b. actual detection: in the scanning process, the emission probe of the acoustic detection device emits an acoustic signal which passes through the inside of the composite material board, and the acoustic receiving probe on the opposite side receives the detection signal; at the same time, the electromagnetic detection device detects the two detection surfaces of the composite board, forming a scanning detection of the sandwiched composite board; c. detection signal extraction and image reconstruction: the detection instrument receives the detection signal for data image analysis; d. comprehensive defect analysis: the detection signal data of the acoustic detection device is mainly used for analyzing the middle layer of the detected composite material; at the same time of detection, the acoustic vibration signal affects the stress of the joint part of the composite board, and the magnetic detection is carried out, so as to fuse and analyze the detection data at the same time, and determine the uniformity defect of the composite material. The detection signal extraction is to extract the information data of the hollow position of the middle layer of the composite material detected by the acoustic vibration detection device. The middle layer hollow position information data is the detection data of the center position of the regular hollow geometry of the middle layer for acoustic signal detection analysis. The acoustic detection device extracts the detection signal of the hollow position of the middle layer, and the magnetic detection device extracts the detection signal of the joint part at the same time. The acoustic detection and magnetic detection devices are arranged in an array, and the continuous scanning detection of the multiple detection devices extracts the detection signal data of the continuous multiple same hollow parts and joint parts for analysis and evaluation and determination of the uniformity of the composite material.

2. The method of claim 1, wherein ​ 3. The method of claim 2, wherein ​ 4. The method of claim 3, wherein ​ 5. The method of claim 4, wherein ​ 6. An electromagnetic acoustic transmission device for detecting inhomogeneities in a non-metallic, weakly conductive, weakly magnetically permeable composite material, the composite material having a honeycomb layer in the middle layer, the device comprising an acoustic vibration detection device (23), a magnetic field detection device (24), characterized in that It also includes first detection probe (2a) and second detection probe (2b), first detection plate (21) and second detection plate (22), the first detection probe (2a) and second detection probe (2b) are respectively arranged on the first detection plate (21) and the second detection plate (22) which are arranged in parallel, the acoustic emission probe (231) and the acoustic receiving probe (232) of the acoustic vibration detection device (23) are respectively arranged opposite to the first detection plate (21) and the second detection plate (22), and the first magnetic detection coil (241) and the second magnetic detection coil (242) of the magnetic detection device are respectively arranged around the acoustic emission probe (231) and the acoustic receiving probe (232); the acoustic emission probe (231) and the acoustic receiving probe (232) are respectively provided with the same magnetic detection device, the first magnetic detection coil (241) and the second magnetic detection coil (242) of the same magnetic detection device are arranged around the acoustic emission probe (231) and the acoustic receiving probe (232); the detection device is also provided with guide rails for slidably fixing and adjusting the positions of the first detection probe (2a) and the second detection probe (2b) which can adjust the first detection plate (21) and the second detection plate (22) respectively.

7. The apparatus according to claim 6, wherein It also includes multiple pairs of first detection probe (2a) and second detection probe (2b) which are arranged in array on the first detection plate (21) and the second detection plate (22).

8. The apparatus according to claim 7, wherein The multiple pairs of first detection probe (2a) and second detection probe (2b) are adjusted in distance by the guide rails arranged to slide and adjust the distance of each pair of first detection probe (2a) and second detection probe (2b) arranged on the first detection plate (21) and the second detection plate (22).

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