Flexible ultrasonic array detection method for non-open interior cavities of composite structures

Abstract

The present application relates to the technical field of nondestructive testing, in particular to a flexible ultrasonic array detection method for non-open inner cavity of composite material structure. The flexible ultrasonic scanner is used to pull the flexible ultrasonic array transducer, so that the flexible ultrasonic array transducer moves in a linear direction for scanning. The signal of the array wafer of the flexible ultrasonic array transducer is transmitted to the ultrasonic array unit for processing, so as to realize ultrasonic automatic scanning detection of the non-open inner cavity of the composite material with different lengths. The ultrasonic rapid automatic scanning detection of the inner reinforcing rib of the non-open inner cavity of the composite material structure can be completed by one scanning. The detection automation degree is high, the detection efficiency is high, the detection result can be recorded and visualized, the defect positioning is easy, the detection result is less affected by the technical state and subjective factors of the detector, and the detectability, detection efficiency and reliability of the inner reinforcing rib of the non-open inner cavity of the composite material structure are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, and in particular to a flexible ultrasonic array testing method for non-open cavities of composite material structures. Background Technology

[0002] Non-open cavities in composite material structures are a crucial structural form, demanding extremely high quality. To ensure the quality of these cavities, 100% non-destructive testing is required. Due to the confined space and elongated geometric characteristics of these cavities, current testing primarily employs ultrasonic reflection methods. To achieve comprehensive testing of the non-open cavities, ultrasonic scanning of inaccessible areas within the cavity is necessary.

[0003] Please refer to Figure 1 The current ultrasonic testing method is as follows: a manual scanning method is adopted. The ultrasonic transducer 2 is inserted through the scanning rod from the opening end of the non-open inner cavity 1 of the composite material structure. The ultrasonic transducer 2 is inserted through the scanning rod to realize the manual ultrasonic scanning test of the reinforcing ribs. The main shortcomings are: (1) the ultrasonic transducer 2 usually adopts a single crystal probe, which has low detection efficiency and high labor intensity; (2) it is difficult to accurately realize the coverage scan of the reinforcing ribs of the non-open inner cavity 1 of the composite material structure, which easily leads to missed detection; (3) the degree of automation of ultrasonic testing is low, and the test results are greatly affected by the technical status and subjective factors of the tester, which easily leads to missed detection; (4) the test results cannot be recorded and visualized, which affects the reliability of the test results; (5) it is difficult to detect and locate defects.

[0004] As an improvement, automated ultrasonic scanning inspection is employed. Currently, the commonly used ultrasonic inspection method involves a specialized scanning mechanism that allows the ultrasonic transducer 2 to extend into the non-open cavity 1 of the composite material structure to scan the reinforcing ribs. Its main drawback is:

[0005] (1) When the non-open inner cavity 1 of the composite material structure exceeds 1m or even reaches 20m, due to the geometric size limitation of the non-open inner cavity 1 of the composite material structure, the mechanical stiffness and strength of the scanning mechanism are difficult to guarantee the accurate ultrasonic automatic scanning detection and defect location requirements of the transducer for the internal reinforcing ribs of the non-open inner cavity 1 of the composite material structure, thus affecting the detection effect and the reliability of the detection results, and making it difficult to achieve reliable detection of the non-open inner cavity 1 of the composite material structure; (2) Low detection efficiency. Summary of the Invention

[0006] (1) Technical problems to be solved

[0007] This invention provides a flexible ultrasonic array detection method for non-open cavities of composite material structures, in order to solve the technical problems of low detectability, low detection efficiency, and low detection reliability of internal reinforcing ribs in non-open cavities of composite material structures.

[0008] (2) Technical solution

[0009] This invention provides a method for testing non-open cavities of composite material structures using a flexible ultrasonic array, comprising the following steps: placing the non-open cavity of the composite material structure to be tested on a testing fixture; applying a liquid coupling medium to the surface of the reinforcing ribs in the non-open cavity of the composite material structure; placing a flexible ultrasonic array transducer in the non-open cavity of the composite material structure to be tested; connecting the front flexible connection end of the flexible ultrasonic array transducer to a flexible ultrasonic scanner located at one end of the non-open cavity of the composite material structure to be tested via a flexible connection line; connecting the rear flexible connection end of the flexible ultrasonic array transducer to a flexible ultrasonic scanner located at the other end of the non-open cavity of the composite material structure to be tested via a flexible connection line; turning on the power supply of the ultrasonic array unit and setting parameters in the ultrasonic array unit operation interface; the ultrasonic array unit controlling the flexible ultrasonic scanner to rewind the flexible connection line and pulling the flexible ultrasonic array transducer to move directionally within the non-open cavity of the composite material structure to be tested for scanning; the flexible ultrasonic array transducer transmitting the scanning information to the ultrasonic array unit; and the ultrasonic array unit analyzing and evaluating the test results.

[0010] Furthermore, the flexible ultrasonic array transducer maintains tension with the top of the non-open inner cavity of the composite material structure through the left and right flexible rods, so that the bottom of the flexible ultrasonic array transducer maintains contact coupling with the surface of the reinforcing rib, and the left and right flexible rods respectively contact the top of the non-open inner cavity of the composite material structure through the left and right guide wheels.

[0011] Furthermore, the external dimensions of the flexible ultrasonic array transducer are selected to satisfy the design formula: M = H ± K1; N = W ± K2; where M is the height of the flexible ultrasonic array transducer, N is the width of the flexible ultrasonic array transducer, H is the height of the reinforcing rib of the non-open inner cavity of the composite material structure being tested, W is the width of the reinforcing rib of the non-open inner cavity of the composite material structure being tested, K1 is the vertical mechanical coefficient, and K2 is the horizontal mechanical coefficient.

[0012] Furthermore, the length of the flexible connecting line is selected to satisfy the following condition: the length of the flexible connecting line is greater than the sum of the length of the non-open inner cavity of the composite material structure being tested and the working distance between the flexible ultrasonic scanner and the end face of the non-open inner cavity of the composite material structure being tested.

[0013] Furthermore, the flexible ultrasonic scanner uses a motor to rotate and drive a winding shaft to wind up the flexible connecting wire, thereby pulling the flexible ultrasonic array transducer closer to the flexible ultrasonic scanner.

[0014] Furthermore, the motor controls the rotation angle via a rotation controller, and the motor detects the rotation angle via an encoder.

[0015] Furthermore, the parameters set for the ultrasonic array unit include ultrasonic signal gain, signal gate, scanning speed, and scanning length.

[0016] Furthermore, it also includes post-processing: after the test is completed, the power supply to the ultrasonic array unit is disconnected, the connections of each part are released, the test site is cleaned up, and each part is placed in its corresponding toolbox.

[0017] (3) Beneficial effects

[0018] In summary, this invention uses a flexible ultrasonic scanner to pull a flexible ultrasonic array transducer, causing it to move and scan along a straight line. The signals from the array wafers of the flexible ultrasonic array transducer are then transmitted to an ultrasonic array unit for processing, enabling automated ultrasonic scanning and inspection of non-open cavities of composite materials of varying lengths. A single scan can complete the rapid and automated ultrasonic scanning and inspection of the reinforcing ribs inside the non-open cavities of composite material structures. This method boasts a high degree of automation, high efficiency, low risk of missed detections, low labor intensity, and is environmentally friendly. The inspection results can be recorded and visualized, making defect location easy. The results are less affected by the operator's technical skill and subjective factors, thus significantly improving the inspectability, efficiency, and reliability of the reinforcing ribs inside the non-open cavities of composite material structures. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a composite material structure with a non-open internal cavity.

[0021] Figure 2 This is a schematic diagram of the connection relationship of a flexible ultrasonic array detection system for non-open cavities of composite material structures.

[0022] Figure 3 This is a schematic diagram of the structure of a flexible ultrasonic array transducer used in a flexible ultrasonic array detection system for non-open cavities of composite material structures.

[0023] Figure 4 This is a schematic diagram showing the connection between a flexible ultrasonic array transducer and a flexible ultrasonic scanner in a flexible ultrasonic array testing system for non-open cavities of composite material structures.

[0024] In the diagram: 1. Non-open internal cavity of composite material structure; 2. Ultrasonic transducer; 3. Flexible ultrasonic array transducer; 4. Flexible ultrasonic scanner; 5. Ultrasonic array unit; 30. Left flexible rod; 31. Right flexible rod; 32. Left guide wheel; 33. Right guide wheel; 40. Motor; 41. Flexible seat; 42. Support; 43. Rewinding shaft; 44. Flexible connecting line; 45. Encoder; 46. Rotation controller; 50. Instrument support; 6. Power supply; 7. Support base. Detailed Implementation

[0025] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Please refer to Figures 2-4 A flexible ultrasonic array detection system for non-open cavities of composite material structures is proposed, comprising: a flexible ultrasonic array transducer 3, a flexible ultrasonic scanner 4, and an ultrasonic array unit 5.

[0028] The bottom of the flexible ultrasonic array transducer 3 is provided with an array of crystals for scanning the reinforcing ribs to be inspected within the non-open cavity 1 of the composite material structure. The array of crystals comprises n piezoelectric crystals, where n is calculated using the following formula:

[0029]

[0030] Where w is the width of the piezoelectric crystal, L is the side length of the reinforcing rib of the non-open inner cavity 1 of the composite material structure, and Δw is the spacing between two adjacent piezoelectric crystals. Since the array crystal consists of n piezoelectric crystals and covers the entire cross-section of the reinforcing rib of the non-open inner cavity 1 of the composite material structure being inspected, the probe does not need to scan along the cross-section of the reinforcing rib to achieve ultrasonic scanning of the entire reinforcing rib cross-section. Compared with a single-crystal probe, which requires scanning along the cross-section of the reinforcing rib, this significantly improves detection efficiency. The length of the piezoelectric crystal is 8–20 mm, and the width of the piezoelectric crystal is 0.8–3 mm. The thickness of the piezoelectric crystal is determined according to the required frequency, which is determined based on the thickness and material properties of the non-open inner cavity 1 of the composite material structure being inspected, as well as the defect detection requirements; generally, the frequency is selected between 5 and 10 MHz.

[0031] The flexible ultrasonic scanner 4 includes two sets respectively disposed at both ends of the non-open inner cavity 1 of the composite material structure, and is connected to the front flexible connection end and the rear flexible connection end of the flexible ultrasonic array transducer 3 respectively by a flexible connecting line 44. The flexible ultrasonic array transducer 3 is pulled, and the flexible ultrasonic scanner 4 can select to scan and detect the flexible ultrasonic array transducer 3 along one end of the non-open inner cavity 1 of the composite material structure, or it can select to scan and detect the flexible ultrasonic array transducer 3 along the other end of the non-open inner cavity 1 of the composite material structure, so that the flexible ultrasonic array transducer 3 moves and scans in a straight line.

[0032] The ultrasonic array unit 5 is disposed outside the non-open cavity 1 of the composite material structure and is connected to the array wafer via the ultrasonic signal connection terminal of the flexible ultrasonic array transducer 3 for processing the signal of the array wafer. The flexible ultrasonic array transducer 3 is pulled by the flexible ultrasonic scanner 4, causing it to move and scan in a straight line. The signal from the array wafer of the flexible ultrasonic array transducer 3 is then transmitted to the ultrasonic array unit 5 for processing. This enables automatic ultrasonic scanning and inspection of non-open cavities of composite materials of different lengths. A single scan can complete the rapid automatic ultrasonic scanning and inspection of the internal reinforcing ribs of the non-open cavity 1 of the composite material structure. The inspection is highly automated, efficient, and less prone to missed detections, requiring less labor and is environmentally friendly. The inspection results can be recorded and visualized, making defect location easy. The results are less affected by the inspector's technical condition and subjective factors, thus significantly improving the inspectability, efficiency, and reliability of the internal reinforcing ribs of the non-open cavity 1 of the composite material structure.

[0033] In some embodiments, the flexible ultrasonic array transducer 3 further includes a flexible rod and a guide wheel. One end of the flexible rod is connected to the top of the flexible ultrasonic array transducer 3, and the other end of the flexible rod is connected to the guide wheel. To achieve better contact between the array wafer and the surface of the reinforcing rib being tested, the flexible rod enables adaptive adjustment in the vertical direction. That is, the array wafer contacts the bottom of the non-open inner cavity 1 of the composite material structure, and the guide wheel at the other end of the flexible rod contacts the top of the non-open inner cavity 1 of the composite material structure, achieving a certain degree of tension. This ensures that during the scanning process, the array wafer remains in contact with the surface of the reinforcing rib being tested, forming a stable ultrasonic wave transmission and reception state.

[0034] In some embodiments, the flexible rod includes a left flexible rod 30 and a right flexible rod 31. The flexible rod may be a telescopic rod with a spring installed. The left flexible rod 30 and the right flexible rod 31 are symmetrically arranged on the top of the flexible ultrasonic array transducer 3 and are respectively connected to the left guide wheel 32 and the right guide wheel 33, so that the force on both sides is more balanced during movement. At the same time, the guide wheels can reduce the dynamic friction force generated by contact, thereby facilitating the movement of the flexible ultrasonic array transducer 3.

[0035] In some embodiments, the flexible ultrasonic scanner 4 includes a motor 40, a flexible base 41, and supports 42. The motor 40 is mounted on the top of the flexible base 41, and a winding shaft 43 is connected downwards to the shaft of the motor 40. Supports 42 are respectively located at the four corners of the lower end of the flexible base 41. The height of the supports 42 is adjustable. A cable outlet is provided on one side of the flexible base 41. One end of the flexible connecting cable 44 is fixed to the winding shaft 43, and the other end is connected to the front flexible connection end of the flexible ultrasonic array transducer 3 through the cable outlet. The length of the flexible connecting cable 44 matches the length of the non-open inner cavity 1 of the composite material structure. The rotation of the motor 40 drives the winding shaft 43 to wind the flexible connecting cable 44, thereby pulling the flexible ultrasonic array transducer 3 closer to the flexible ultrasonic scanner 4, thus realizing the moving scanning of the flexible ultrasonic array transducer 3.

[0036] In some embodiments, the motor 40 includes an encoder 45 and a rotation controller 46. The encoder 45 is used to detect the rotation angle of the motor 40, and the rotation controller 46 is used to control the rotation angle of the motor 40. The combined use of the encoder 45 and the rotation controller 46 achieves closed-loop control of the motor 40, thereby accurately controlling the movement distance of the flexible ultrasonic array transducer 3.

[0037] In some embodiments, the ultrasonic array unit 5 includes an ultrasonic array instrument host, a motor 40 control connector, an encoder 45 connector, and an ultrasonic array signal connector. The ultrasonic array instrument host is equipped with the motor 40 control connector, the encoder 45 connector, and the ultrasonic array signal connector. The motor 40 control connector is electrically connected to the rotation controller 46, the encoder 45 connector is electrically connected to the encoder 45, and the ultrasonic array signal connector is electrically connected to the ultrasonic signal connection terminal. The ultrasonic array instrument host controls the movement of the flexible ultrasonic array transducer 3 and performs ultrasonic array signal transmission / reception, detection, and image display on the flexible ultrasonic array transducer 3.

[0038] In some embodiments, instrument supports 50 are respectively provided at the four corners of the lower end of the ultrasonic array instrument host. The height of the instrument supports 50 is adjustable, so that the ultrasonic array instrument host can adapt to the needs of various sites and obtain a stable operating environment.

[0039] In some embodiments, a power supply 6 is also included, which is composed of a rechargeable battery pack and provides working power 6 for the flexible ultrasonic array transducer 3, the flexible ultrasonic scanner 4 and the ultrasonic array unit 5, adapting to the needs of various sites and having good flexibility.

[0040] In some embodiments, a support base 7 is also included. The non-open inner cavity 1 of the composite material structure is placed on two or more of the support bases 7. The support bases 7 can conveniently fix the non-open inner cavity 1 of the composite material structure and level it to facilitate ultrasonic automatic scanning and detection.

[0041] An embodiment of the present invention proposes a flexible ultrasonic array detection method for non-open cavities of composite material structures, comprising the following steps:

[0042] The non-open inner cavity 1 of the composite material structure to be tested is placed on the testing fixture;

[0043] A liquid coupling medium is applied to the surface of the reinforcing ribs in the non-open inner cavity 1 of the composite material structure.

[0044] The flexible ultrasonic array transducer 3 is placed in the non-open cavity 1 of the composite material structure being tested;

[0045] The front flexible connection end of the flexible ultrasonic array transducer 3 is connected to the flexible ultrasonic scanner 4, which is located at one end of the non-open inner cavity 1 of the composite material structure being tested, via a flexible connection line 44.

[0046] The flexible connection end of the flexible ultrasonic array transducer 3 is connected to the flexible ultrasonic scanner 4, which is located at the other end of the non-open inner cavity 1 of the composite material structure being tested, via a flexible connection line 44.

[0047] Turn on the power supply 6 of the ultrasonic array unit 5 and enter the operation interface of the ultrasonic array unit 5 to set parameters.

[0048] The ultrasonic array unit 5 controls the flexible ultrasonic scanner 4 to wind up the flexible connecting wire 44 and pulls the flexible ultrasonic array transducer 3 to move directionally in the non-open inner cavity 1 of the composite material structure being inspected for scanning.

[0049] The flexible ultrasonic array transducer 3 transmits the scanning information to the ultrasonic array unit 5;

[0050] The ultrasonic array unit 5 analyzes and evaluates the test results.

[0051] In some embodiments, the flexible ultrasonic array transducer 3 maintains tension with the top of the non-open inner cavity 1 of the composite material structure through the left flexible rod 30 and the right flexible rod 31, so that the bottom of the flexible ultrasonic array transducer 3 maintains contact coupling with the surface of the reinforcing rib, and the left flexible rod 30 and the right flexible rod 31 are in contact with the top of the non-open inner cavity 1 of the composite material structure through the left guide wheel 32 and the right guide wheel 33, respectively.

[0052] In some embodiments, the external dimensions of the flexible ultrasonic array transducer 3 are selected to satisfy the design formula:

[0053] M = H ± K1;

[0054] N = W ± K2;

[0055] Where M is the height of the flexible ultrasonic array transducer 3, N is the width of the flexible ultrasonic array transducer 3, H is the height of the reinforcing rib of the non-open inner cavity 1 of the composite material structure under test, and W is the width of the reinforcing rib of the non-open inner cavity of the composite material structure under test; K1 is the vertical mechanical coefficient, and K2 is the horizontal mechanical coefficient. This ensures a suitable size, facilitating the placement of the flexible ultrasonic array transducer 3 into the non-open inner cavity 1 of the composite material structure, while also ensuring good stability.

[0056] In some embodiments, the length of the flexible connecting line 44 is selected to satisfy the following condition: the length of the flexible connecting line 44 is greater than the sum of the length of the non-open inner cavity 1 of the composite material structure being tested and the working distance between the flexible ultrasonic scanner 4 and the end face of the non-open inner cavity 1 of the composite material structure being tested.

[0057] In some embodiments, the flexible ultrasonic scanner 4 uses a motor 40 to rotate and drive a winding shaft 43 to wind up the flexible connecting line 44, thereby pulling the flexible ultrasonic array transducer 3 closer to the flexible ultrasonic scanner 4.

[0058] In some embodiments, the motor 40 controls the rotation angle via a rotation controller 46, and the motor 40 detects the rotation angle via an encoder 45.

[0059] In some embodiments, the parameters set for the ultrasonic array unit 5 include ultrasonic signal gain, signal gate, scanning speed, and scanning length.

[0060] In some embodiments, post-processing is also included, in which the power supply 6 of the ultrasonic array unit 5 is disconnected after the test is completed, the connections of each part are disconnected and the test site is cleaned, and each part is placed in its corresponding toolbox.

[0061] Example:

[0062] Flexible ultrasonic array transducers 3 with n=32, 64, and 128 were selected. The length of each crystal was 8, 10, and 20 mm, and the width Δw of each crystal was 0.8, 1, and 2 mm, respectively. The frequencies were 5 MHz and 7.5 MHz. A series of flexible ultrasonic array scanning tests were carried out on the internal reinforcing ribs of non-open inner cavities 1 of composite material structures with lengths of 1 m, 3 m, 5 m, and 15 m. The test results show that the present invention can effectively perform ultrasonic coverage scanning tests on the non-open inner cavities 1 of the composite material structures under test, achieving the expected rapid ultrasonic scanning effect.

[0063] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0064] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A flexible ultrasonic array inspection method for non-open interior cavities of composite structures, characterized by, The method comprises the steps of: placing the non-open inner cavity of the composite material structure to be detected on a detection tool; applying liquid coupling medium on the surface of the stiffener in the non-open inner cavity of the composite material structure; placing a flexible ultrasonic array transducer in the non-open inner cavity of the composite material structure to be detected; connecting the front flexible connection end of the flexible ultrasonic array transducer to the flexible ultrasonic scanner arranged at one end of the non-open inner cavity of the composite material structure to be detected through a flexible connection line; connecting the rear flexible connection end of the flexible ultrasonic array transducer to the flexible ultrasonic scanner arranged at the other end of the non-open inner cavity of the composite material structure to be detected through a flexible connection line; turning on the power supply of the ultrasonic array unit and entering the operating interface of the ultrasonic array unit to set parameters; controlling the flexible ultrasonic scanner to wind the flexible connection line and pull the flexible ultrasonic array transducer to move directionally in the non-open inner cavity of the composite material structure to be detected for scanning; transmitting the scanning information to the ultrasonic array unit by the flexible ultrasonic array transducer; analyzing and evaluating the detection results by the ultrasonic array unit; the flexible ultrasonic array transducer maintains tension with the top of the non-open inner cavity of the composite material structure through the left flexible rod and the right flexible rod, so that the bottom of the flexible ultrasonic array transducer maintains contact and coupling with the surface of the stiffener, and the left flexible rod and the right flexible rod respectively contact the top of the non-open inner cavity of the composite material structure through the left guide wheel and the right guide wheel.

2. A flexible ultrasonic array inspection method for non-opened cavities in composite structures according to claim 1, characterized in that, the size of the flexible ultrasonic array transducer is selected to satisfy the design formula: M = H ± K1 N = W ± K2 wherein, M is the height of the flexible ultrasonic array transducer, N is the width of the flexible ultrasonic array transducer, H is the height of the stiffener of the non-open inner cavity of the composite material structure to be detected, W is the width of the stiffener of the non-open inner cavity of the composite material structure to be detected, K1 is the vertical mechanical coefficient, and K2 is the horizontal mechanical coefficient.

3. The method of claim 1, wherein the method is used for flexible ultrasonic array inspection of non-open interior cavities of composite structures. the length of the flexible connection line is selected to satisfy that the length of the flexible connection line is greater than the sum of the length of the non-open inner cavity of the composite material structure to be detected and the working distance between the flexible ultrasonic scanner and the end face of the non-open inner cavity of the composite material structure to be detected.

4. The method of claim 1, wherein the method is used for flexible ultrasonic array inspection of non-open interior cavities of composite structures. the flexible ultrasonic scanner winds the flexible connection line through the rotating motor to pull the flexible ultrasonic array transducer close to the flexible ultrasonic scanner.

5. A method for flexible ultrasonic array inspection of non-open interior cavities of composite structures according to claim 4, wherein, the motor controls the rotation angle through the rotation controller, and the motor detects the rotation angle through the encoder.

6. The method of claim 1, wherein, the parameters set by the ultrasonic array unit include ultrasonic signal gain, signal gate, scanning speed, and scanning length.

7. A method for flexible ultrasonic array inspection of non-open cavities in composite structures according to any one of claims 1 to 6, characterized in that, the method further comprises post-processing, i.e., after the detection is completed, the power supply of the ultrasonic array unit is turned off, the connections of the parts are released, the detection site is cleaned, and the parts are placed in the corresponding toolboxes.

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