Method for detecting hybrid manufacturing defects of honeycomb sandwich composite structures based on wave packet energy integration

Abstract

The application relates to a honeycomb sandwich composite structure hybrid manufacturing defect detection method based on wave packet energy integration, which comprises the following steps: exciting ultrasonic guided waves at a first boundary of a honeycomb sandwich structure to be detected, and collecting out-of-plane vibration time domain signals of at least one detection position at an excitation point; processing the out-of-plane vibration time domain signals, and extracting energy integration features of the signals in a pre-defined time window; and outputting a detection result of whether a defect exists in a propagation path corresponding to the detection position based on comparison between the energy integration features and preset baseline features. Compared with the prior art, the application has the advantages of high efficiency, strong reliability and excellent robustness.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, and in particular to a method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration. Background Technology

[0002] Honeycomb sandwich composite structures, formed by bonding two layers of panels to a honeycomb core, offer advantages such as light weight, high specific strength, high specific stiffness, and excellent thermal and sound insulation, making them widely used in aerospace manufacturing. However, due to their unique structure and complex manufacturing process, these materials are prone to internal defects such as delamination and peeling during production and service, severely impacting structural strength and integrity and threatening overall safety. These defects are typically hidden within the structure and difficult to detect through visual inspection; therefore, non-destructive testing techniques suitable for honeycomb sandwich composites are needed.

[0003] Currently, commonly used non-destructive testing methods for honeycomb sandwich structures mainly include X-ray inspection, microwave inspection, infrared inspection, and ultrasonic inspection. While X-ray inspection offers high resolution, it suffers from radiation hazards and artifact interference; microwave inspection boasts high sensitivity but is susceptible to environmental humidity; infrared inspection provides intuitive results, but its resolution is easily affected by various factors, resulting in insufficient stability. Ultrasonic inspection, as a mainstream method, offers advantages such as high sensitivity, strong penetration, and portable equipment; however, traditional ultrasonic C-scan requires point-by-point scanning, leading to low inspection efficiency. Ultrasonic guided wave technology, due to its long propagation distance and low energy attenuation, is suitable for global inspection of large structural components. However, existing guided wave transmission inspection methods rely on complex signal feature extraction, typically requiring indicators such as signal amplitude and arrival time for signal evaluation. For honeycomb sandwich structures, debonding and delamination defects exhibit opposite trends in these indicators. This means that when both defects coexist on the inspection path, signal changes cancel each other out, easily leading to missed detections and severely impacting the reliability of the inspection results. Therefore, achieving universal and reliable detection of debonding, delamination, and their mixed defects in honeycomb sandwich composite structures is a technical problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a method for detecting hybrid manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration. A specific time period between the first direct wave packet and the first second boundary reflection wave packet in the guided wave signal is defined as an inter-wave packet time window. The signal envelope energy integration value within this time window is calculated, ensuring that debonding, delamination, and hybrid defects all exhibit a consistent and significant increase in response under this single index. This solves the problem of missed detection of hybrid defects caused by the opposite response trends of different defects in traditional methods, achieving universal and reliable detection of multiple defect types.

[0005] The objective of this invention can be achieved through the following technical solutions: According to one aspect of the present invention, a method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration is provided, the specific steps of which include: S1. Excite an ultrasonic guided wave at the first boundary of the honeycomb sandwich structure to be tested, and collect out-of-plane vibration time-domain signals at at least one detection location at the excitation point; S2. Process the out-of-plane vibration time-domain signal and extract the energy integral features of the signal within a predefined time window; S3. Based on the comparison between the energy integral feature and the preset baseline feature, output the detection result of whether there is a defect in the propagation path corresponding to the detection position.

[0006] Furthermore, the specific steps for extracting the energy integral features include: The envelope of the acquired out-of-plane vibration time-domain signal is extracted to obtain the signal envelope. A time window between wave packets is determined on the signal envelope. The starting point of the time window is the first point after the arrival of the first direct wave packet, and the ending point is the last point before the arrival of the first second boundary reflected wave packet. The cumulative energy of the signal envelope within the inter-wave packet time window is calculated to obtain the inter-wave packet energy integral value at the corresponding detection position.

[0007] Furthermore, the envelope extraction is achieved through Hilbert transform.

[0008] Furthermore, in S1, the relative positions of the excitation point and the acquisition point remain unchanged, and the device moves to the next detection position along a direction parallel to the first boundary. The excitation and acquisition process is repeated until the preset scanning area is covered, and the out-of-plane vibration time-domain signal of each detection position is obtained. When the scanning area covers the entire range of the structure to be detected, a two-dimensional defect distribution map is generated based on the wave packet energy integral value of each detection position, and the overall integrity of the structure is visualized and output.

[0009] Furthermore, based on the inter-wave packet energy integral value corresponding to each detection position, an energy integration scan curve is generated along the scanning direction; the region in the energy integration scan curve where the inter-wave packet energy integral value is significantly higher than the defect-free baseline range is determined to be the defect region.

[0010] Furthermore, the wave packet time window is determined as follows: based on the propagation speed of the ultrasonic guided wave in the honeycomb sandwich structure and the geometric dimensions of the sample, the theoretical arrival times of the first direct wave packet and the first second boundary reflected wave packet are calculated, and then the wave packet time window is defined.

[0011] Furthermore, the center frequency of the excited ultrasonic guided wave is 100kHz, and the sampling frequency of the out-of-plane vibration time-domain signal is not less than 10 times the excitation frequency.

[0012] Furthermore, the preset baseline feature is the range of inter-wave packet energy integral values ​​obtained after performing the same acquisition and processing steps on a defect-free region.

[0013] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0014] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) Solving the problem of missed detection of mixed defects: By extracting the signal envelope and defining the inter-packet time window between the first direct wave packet and the first second boundary reflection wave packet, the energy integral value within the time window is calculated as a unified defect sensitivity index. Unlike existing technical means that rely on signal amplitude or arrival time, this index can capture the extra energy retained in the inter-packet time window due to defect scattering. This makes debonding defects, delamination defects, and mixed defects where both coexist under this index all show a consistent rising response. This avoids the technical risk of missed detection of mixed defects due to the opposite response trends of traditional indices to different defects, and improves the reliability and universality of detection of complex manufacturing defects.

[0016] (2) Simplified detection process and improved efficiency: The detection mode adopts a single-point excitation combined with near-end single-point reception. By performing linear scanning along the direction parallel to the excitation boundary, the energy integral value of the inter-wave packet time window on each propagation path is directly obtained. Compared with the cumbersome process of traditional guided wave detection methods that require full-domain scanning of defect-free structures to extract reference signals, this invention only needs to compare the fluctuation of integral values ​​on each detection path to identify anomalies, without the need to establish a full-domain reference. At the same time, combined with the advantage that a single guided wave excitation can cover long-distance propagation, the number of scanning points and data acquisition time required for detection are greatly reduced, thereby realizing rapid and global health screening of large-size honeycomb sandwich composite material structures.

[0017] (3) Improved stability and reliability of detection results: By calculating the energy integral over a specific time interval between wave packets, this processing method itself has a smoothing and suppression effect on random noise, reducing the sensitivity to fluctuations in the amplitude of a single wave packet signal; by obtaining the energy integral scanning curve of each detection point through linear scanning, the defect is determined based on the continuous occurrence of abnormal areas rather than single-point jumps, effectively eliminating the interference of accidental factors on the detection results. When the receiving position is adjusted, the integral value of the defective path is always stably higher than the defect-free benchmark. Therefore, the method of this invention has a high tolerance for changes in the detection environment and operational differences, and has excellent repeatability and robustness, ensuring the stability and reliability of the detection results. Attached Figure Description

[0018] Figure 1 A flowchart of a hybrid manufacturing defect detection method for honeycomb sandwich composite structures based on inter-wave packet energy integration; Figure 2 This is a schematic diagram of the honeycomb sandwich structure sample in Example 1; Figure 3 This is a comparison chart of the energy integral values ​​between wave packets under different defect states in Example 1; Figure 4 This is a graph showing the fluctuation and robustness verification of the energy integral value between wave packets at different receiving positions in Example 1. Figure 5 This is a schematic diagram of the two-dimensional finite element simulation model of the honeycomb sandwich structure in Example 2; Figure 6 This is a comparison chart of the wave packet time window energy integral values ​​of the four simulation models in Example 2; Figure 7 This is a stability verification diagram of the wave packet time window energy integral value at different sampling points in Example 2. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] Example 1 Honeycomb sandwich composite structures, with their excellent properties such as lightweight, high specific strength, high specific stiffness, and thermal and sound insulation, have become key load-bearing components in the aerospace manufacturing field. However, due to their unique sandwich structure, debonding between the panels and core materials and delamination defects within the panels are highly susceptible to occur during manufacturing and service. These internal defects are highly concealed and difficult to identify through conventional visual inspection, seriously threatening structural integrity and flight safety. Therefore, developing non-destructive testing technologies suitable for this structure is of great significance for ensuring product quality and service reliability.

[0021] Currently, non-destructive testing methods applied to honeycomb sandwich structures mainly include X-ray inspection, microwave inspection, infrared inspection, and ultrasonic inspection. While X-ray inspection offers high resolution, it suffers from radiation hazards and artifact interference; microwave inspection boasts high sensitivity but is susceptible to environmental humidity; infrared inspection provides intuitive results but suffers from insufficient resolution stability. Ultrasonic inspection, as a mainstream technique, offers advantages such as high sensitivity, strong penetration, and portable equipment; however, traditional ultrasonic C-scan requires point-by-point scanning, resulting in low inspection efficiency. Ultrasonic guided wave technology, due to its long propagation distance and low energy attenuation, is suitable for global inspection of large structures. However, existing guided wave transmission inspection methods typically rely on amplitude and time-of-arrival (TOA) metrics when evaluating signals. For honeycomb sandwich structures, debonding and delamination defects exhibit opposite trends in these metrics. This leads to signal cancellation when both defects coexist along the inspection path, easily causing missed detections of mixed defects and severely impacting the reliability of the inspection results. Therefore, this embodiment proposes a method for detecting hybrid manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration. By defining a specific time window between the first direct wave packet and the first second boundary reflected wave packet, and calculating the signal envelope energy integration value within the time window, a unified detection index with consistent sensitivity to debonding, delamination, and hybrid defects is constructed, thereby fundamentally solving the problem of missed detection of hybrid defects.

[0022] like Figure 1 As shown in this embodiment, a method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration is provided. The specific steps include: S1. Excite an ultrasonic guided wave at the first boundary of the honeycomb sandwich structure to be tested, and collect out-of-plane vibration time-domain signals at at least one detection location at the excitation point; S2. Process the time-domain signal of external vibration and extract the energy integral characteristics of the signal within a predefined time window; S3. Based on the comparison between the energy integral characteristics and the preset baseline characteristics, output the detection result of whether there is a defect in the propagation path corresponding to the detection location.

[0023] The specific steps for extracting energy integral features include: The envelope of the acquired out-of-plane vibration time-domain signal is extracted to obtain the signal envelope. Determine the inter-wave packet time window on the signal envelope. The starting point of the inter-wave packet time window is the first point after the arrival of the first direct wave packet, and the ending point is the last point before the arrival of the first second boundary reflected wave packet. The cumulative energy of the signal envelope within the inter-wave packet time window is calculated to obtain the inter-wave packet energy integral value at the corresponding detection position. Envelope extraction is achieved using Hilbert transform.

[0024] In step S1, keeping the relative positions of the excitation point and the acquisition point unchanged, the system moves along a direction parallel to the first boundary to the next detection position, repeating the excitation and acquisition process until the preset scanning area is covered, obtaining the out-of-plane vibration time-domain signal at each detection position. When the scanning area covers the entire range of the structure to be inspected, a two-dimensional defect distribution map is generated based on the wave packet energy integral value at each detection position, providing a visual output of the overall structural integrity. The excitation point should be located as close as possible to the first boundary to reduce the impact of guided wave reflection from the first boundary side on the wave packet time window determination.

[0025] Based on the inter-wave packet energy integral value corresponding to each detection position, an energy integration scan curve is generated along the scanning direction; the region in the energy integration scan curve where the inter-wave packet energy integral value is significantly higher than the defect-free baseline range is determined to be the defect region.

[0026] The wave packet time window is determined as follows: based on the propagation speed of the ultrasonic guided wave in the honeycomb sandwich structure and the geometric dimensions of the sample, the theoretical arrival time of the first direct wave packet and the first second boundary reflected wave packet are calculated, and then the wave packet time window is defined.

[0027] The center frequency of the excited ultrasonic guided wave is 100kHz, and the sampling frequency of the out-of-plane vibration time-domain signal is not less than 10 times the excitation frequency.

[0028] The preset baseline characteristics are the range of inter-wave packet energy integral values ​​obtained after performing the same acquisition and processing steps on a defect-free region.

[0029] This embodiment utilizes the universal detection index of inter-wave packet time window energy integral to produce a consistent rising response for debonding, delamination, and any mixed defects. This avoids the shortcomings of existing detection methods, which are applicable to single-type defects and prone to missed or misjudged mixed defects. It achieves a unified characterization of multiple defects with a single simple index, fundamentally solving the problem of a lack of universal characterization tools for mixed defect detection. Furthermore, traditional guided wave detection methods require a full-domain scan of defect-free structures to extract a reference signal. This embodiment only needs to compare the single-point response results on each propagation path to directly identify energy integral anomalies along the propagation path. Simultaneously, by combining single-point excitation-reception with one-dimensional linear scanning, it can achieve rapid scanning of large-size structures, meeting the engineering requirements for rapid, global health screening of in-service structures. The signal processing in this embodiment only requires Hilbert transform and time-domain energy integral calculation, resulting in low computational load, high speed, and strong real-time performance. Furthermore, the proposed inter-wave packet time window energy integral has a clear physical meaning. It directly quantifies the energy captured by the guided wave due to defect scattering on the propagation path, making the judgment results reliable and avoiding dependence on changes in single wave packet signal indicators. At the same time, the energy integral processing has a certain smoothing and suppression effect on random noise, making the detection indicators more tolerant to differences in detection environment and operation, and exhibiting excellent robustness and repeatability.

[0030] To verify the feasibility and effectiveness of the technical solution in this embodiment, specific experiments were conducted to verify the actual response characteristics of the inter-wave packet energy integral value index in the detection of debonding, delamination, and hybrid defects in honeycomb sandwich structures. Specifically, as shown in... Figure 2 As shown, the honeycomb sandwich composite structure consists of two face panels sandwiching a honeycomb core. Both face panels are 200 mm long, 200 mm wide, and 0.6 mm thick, while the honeycomb core is 200 mm long, 200 mm wide, and 15 mm thick. The honeycomb core unit cell has a regular hexagonal structure with a wall thickness of 0.4 mm. There is a significant difference in impedance between the face panels and the honeycomb core. Debonding and delamination defects were pre-fabricated in the honeycomb sandwich sample, and their positions in the Y direction were marked.

[0031] Furthermore, an air-coupled ultrasonic excitation-three-dimensional laser vibrometer acquisition system was constructed. An air-coupled ultrasonic testing device was used to excite an ultrasonic guided wave signal with a center frequency of 100 kHz near the first boundary. By adjusting the probe's incident angle, a guided wave dominated by low-order antisymmetric modes was excited. A three-dimensional laser vibrometer system was used to acquire single-point out-of-plane vibration signals on the sample surface near the excitation point, ensuring a sufficiently long sampling time to completely capture the first direct wave and the first second boundary reflected wave. The specific sampling parameter settings for the system are shown in Table 1.

[0032] Table 1 Sampling parameter settings for the 3D laser vibrometer system The acquired time-domain signal is subjected to Hilbert transform to extract its envelope. If the signal-to-noise ratio is insufficient, the envelope can be smoothed and filtered. The arrival times of the first direct wave and the first second boundary reflected wave are determined based on the waveguide group velocity and the sample size. The time interval between the two is then defined as the wave packet time window, and the energy accumulation value of the envelope within this time window is calculated, thus obtaining the wave packet time window energy integral value.

[0033] Keeping the relative positions of the excitation and reception constant, the detection position is moved along the Y direction to ensure the scanning path covers defect-free areas, areas containing debonding defects, areas containing delamination defects, and areas containing mixed defects. A Hilbert transform is performed on the time-domain signals acquired at each point, and the energy integral values ​​of the inter-wave packet time window for each region are calculated and compared. The results are as follows: Figure 3 As shown, the inter-wave packet time window energy integral values ​​of paths containing debonding defects, delamination defects, and mixed defects are all significantly higher than the baseline values ​​of defect-free paths. Specifically, the integral value of paths containing debonding defects is increased by 11.51%, the integral value of paths containing delamination defects is increased by 12.31%, and the integral value of paths containing mixed defects is increased by 8.44%. This result confirms that the index proposed in this invention has consistent sensitivity to the various defects and can be used to effectively determine defects.

[0034] To eliminate the randomness of single-point detection and verify the reliability of the method, repeated measurements were performed at the same excitation location, adjusting the receiving position along the X direction perpendicular to the Y direction. The acquired time-domain signals were then processed using Hilbert transform, and the inter-packet time window energy integral value was calculated. The results are as follows: Figure 4 As shown, although the integral values ​​at different receiving points along the same propagation path exhibit normal fluctuations, the integral values ​​of all defective paths are consistently and significantly higher than the defect-free benchmark, effectively eliminating single-point randomness. This demonstrates that the method and proposed index of this invention have excellent repeatability and robustness, and further proves the rationality of the wave packet time window energy integral value as a defect judgment index.

[0035] In summary, the wave packet time window energy integration index proposed in this embodiment can effectively and reliably detect debonding, delamination and mixing defects in honeycomb sandwich structures, and the index has excellent repeatability and robustness.

[0036] Example 2 This embodiment is basically the same as Embodiment 1 in terms of method and steps, except that the effectiveness of the detection method is theoretically verified by using finite element simulation analysis.

[0037] like Figure 5As shown, a two-dimensional model of a honeycomb sandwich structure was established. The two panels are each 200mm long and 0.6mm thick, while the honeycomb core is 200mm long and 15mm thick. The honeycomb core cell spacing is 5.2mm, and the wall thickness is 0.4mm. Significant differences exist in the impedance between the panels and the honeycomb core. For comparative analysis, four sets of honeycomb sandwich structure comparison models were established: one with no defects, one with debonding defects, one with delamination defects, and one with mixed defects. The defect size and location correspond to the pre-set defects in Example 1.

[0038] An air-coupled ultrasonic probe was used to excite an ultrasonic guided wave signal with a center frequency of 100 kHz near the first boundary of the sample. The incident angle was set the same as in Example 1 to excite a low-order antisymmetric guided wave mode. A sampling point was set on the model surface near the excitation point, and the out-of-plane displacement of this point was output to simulate the out-of-plane vibration signal collected by a three-dimensional laser vibrometer. The simulation time needed to be set long enough to ensure complete capture of the first direct wave and the first second boundary reflected wave.

[0039] Hilbert transforms were performed on the time-domain signals output by the four models to extract their envelopes. The inter-wave packet time window was determined based on the wave velocity and model size, and the energy integral value of the inter-wave packet time window for each model was calculated. The results are as follows: Figure 6 As shown, the wave packet time window energy integral values ​​of the models containing debonding defects, layering defects, and mixed defects are all significantly higher than the baseline values ​​of the defect-free model. Specifically, the path integral value containing debonding defects increases by 10.07%, the path integral value containing layering defects increases by 62.55%, and the path integral value containing mixed defects increases by 44.38%. This trend is completely consistent with the experimental results of Example 1, which theoretically confirms the universal sensitivity of the index proposed in this invention to different types of defects.

[0040] To verify the stability of the simulation results, the positions of the data acquisition points along the length direction in each model were changed, and multiple calculations were performed. The results are as follows: Figure 7 As shown, although the integral values ​​of different output points in the same model fluctuate normally, the integral values ​​of all defective models are consistently and significantly higher than the defect-free benchmark. This proves that the index also has excellent repeatability and robustness in the simulation environment, eliminating random errors.

[0041] In summary, this embodiment theoretically verifies the effectiveness of the wave packet time window energy integral index for debonding, delamination, and mixing defects in honeycomb sandwich structures through systematic finite element simulation, and the simulation results corroborate the experimental results.

[0042] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0043] The electronic device of this invention includes a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) or loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0044] Multiple components in the device are connected to an I / O interface, including: input units such as a keyboard, mouse, etc.; output units such as various types of displays, speakers, etc.; storage units such as disks, optical disks, etc.; and communication units such as network interface cards, modems, wireless transceivers, etc. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks. The processing unit performs the various methods and processes described above, such as the method of the present invention. For example, in some embodiments, the method of the present invention may be implemented as a computer software program tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or the communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of the method of the present invention described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute the method of the present invention by any other suitable means (e.g., by means of firmware).

[0045] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0046] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0047] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0048] 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 person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered 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 detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration, characterized in that, The specific steps include: S1. Excite an ultrasonic guided wave at the first boundary of the honeycomb sandwich structure to be tested, and collect out-of-plane vibration time-domain signals at at least one detection location at the excitation point; S2. Process the out-of-plane vibration time-domain signal and extract the energy integral features of the signal within a predefined time window; S3. Based on the comparison between the energy integral feature and the preset baseline feature, output the detection result of whether there is a defect in the propagation path corresponding to the detection position.

2. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, The specific steps for extracting the energy integral features include: The envelope of the acquired out-of-plane vibration time-domain signal is extracted to obtain the signal envelope. A time window between wave packets is determined on the signal envelope. The starting point of the time window is the first point after the arrival of the first direct wave packet, and the ending point is the last point before the arrival of the first second boundary reflected wave packet. The cumulative energy of the signal envelope within the inter-wave packet time window is calculated to obtain the inter-wave packet energy integral value at the corresponding detection position.

3. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, The envelope extraction is achieved through Hilbert transform.

4. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, In step S1, the relative positions of the excitation point and the acquisition point remain unchanged, and the device moves to the next detection position along a direction parallel to the first boundary. The excitation and acquisition process is repeated until the preset scanning area is covered, and the out-of-plane vibration time-domain signal of each detection position is obtained. When the scanning area covers the entire range of the structure to be detected, a two-dimensional defect distribution map is generated based on the wave packet energy integral value of each detection position, and the overall integrity of the structure is visualized.

5. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, Based on the inter-wave packet energy integral value corresponding to each detection position, an energy integration scan curve is generated along the scanning direction; the region in the energy integration scan curve where the inter-wave packet energy integral value is significantly higher than the defect-free baseline range is determined to be the defect region.

6. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 2, characterized in that, The wave packet time window is determined as follows: based on the propagation speed of the ultrasonic guided wave in the honeycomb sandwich structure and the geometric dimensions of the sample, the theoretical arrival time of the first direct wave packet and the first second boundary reflected wave packet are calculated, and then the wave packet time window is defined.

7. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, The center frequency of the excited ultrasonic guided wave is 100kHz, and the sampling frequency of the out-of-plane vibration time-domain signal is not less than 10 times the excitation frequency.

8. The method for detecting manufacturing defects in honeycomb sandwich composite material structures based on inter-wave packet energy integration according to claim 1, characterized in that, The preset baseline feature is the range of inter-wave packet energy integral values ​​obtained after performing the same acquisition and processing steps on a defect-free region.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 8.

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