Foreign matter impact monitoring device, method and system for composite material structure

Abstract

The invention belongs to the technical field of structure health monitoring, provides a foreign matter impact monitoring device, method and system for a composite material structure, solves the problem that a foreign matter impact event is difficult to detect in the application process of a composite material structure component, can practically guarantee the service safety of the structure, reduces the overhaul and maintenance times, and improves the safety of the structure. According to the technical scheme, the method comprises the steps of receiving a multi-channel electric signal generated by a PVDF piezoelectric film when a composite material structure is impacted by a foreign matter, performing data storage according to a preset rule, obtaining a normal working condition threshold value according to a change rule of a characteristic value of the electric signal, and when the characteristic value of a certain signal exceeds the normal working condition threshold value, determining that the composite material structure is impacted by the foreign matter. And judging whether the signal is impacted by foreign matters or not by combining the signal and the previous signal.

Description

Technical Field

[0001] The present invention belongs to the technical field of structural health monitoring, and in particular relates to a device, method and system for monitoring foreign body impact on a composite material structure. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Since composite structural components may cause defects such as delamination when impacted by foreign objects, resulting in a decrease in the structural bearing capacity, the current solutions in the aviation and other fields are: use a "building block" test method to verify the impact of possible impact damage on the residual strength of the structure; use a "planned maintenance" model to regularly check whether the structure is damaged and conduct an assessment; install online monitoring sensors and equipment, such as active and passive structural health monitoring sensors and systems based on piezoelectric arrays.

[0004] The "building block" test method requires a large number of multi-level tests of specimens-features-full-size components, which is costly. The "planned repair" method generally uses visual methods to detect surface damage of composite structures, which may result in missed detections. The online monitoring sensors currently used are generally divided into piezoelectric arrays, fiber gratings and smart coatings, which can be integrated with the structure, but there are still problems such as high cost of data acquisition equipment, including the piezoelectric data acquisition hardware has many functions and redundant design. The high-speed optical modules of fiber grating data acquisition hardware still rely on imports, making it difficult to reduce costs. Smart coatings are difficult to apply on a large scale in the field of composite materials due to their own technical limitations.

[0005] Existing test methods, such as "Research on Test Methods for Post-Impact Compression Strength of Composite Structures [C]. / / Proceedings of the 17th National Composite Materials Conference. 2012: 824-82", are based on the composite building block test. The influencing parameters related to post-impact compression strength are obtained from the specimen level test, and the basic value of post-impact compression strength is obtained from the sub-component level test. Finally, the design allowable value of post-impact compression strength of T800-grade toughened epoxy resin-based composite structures that meet engineering applications is given. There are 180 test pieces in the test matrix, which requires a lot of manpower and financial resources.

[0006] Existing proposals for piezoelectric smart layers (SMART Layer), such as the publication number "CN115103510A" and the invention name "Composite material smart structure with symmetrical embedded piezoelectric smart layer and preparation method thereof", bury the piezoelectric smart layer flexible sensor between the composite material layers to realize foreign body impact monitoring and active damage scanning monitoring; in terms of data acquisition hardware, NI-based PCI and PXI architectures are adopted. Both architectures require the purchase of NI boards, which are relatively costly. Summary of the invention

[0007] In order to solve at least one technical problem existing in the above-mentioned background technology, the first aspect of the present invention provides a foreign body impact monitoring device for a composite material structure, which utilizes a PVDF piezoelectric film array flexible sensor and a data acquisition device and system to monitor foreign body impact events, thereby solving the problem that foreign body impact events of composite material structural components are difficult to detect during use, and can effectively ensure the service safety of the structure, reduce the number of inspections and maintenance, and support the transformation from "planned maintenance" to "condition-based maintenance".

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A composite material structure foreign body impact monitoring device, comprising a composite material structure, a data acquisition device and a data center, wherein a sensor composed of a PVDF piezoelectric film is arranged on the composite material structure, and the data acquisition device is connected to the sensor and the data center respectively;

[0010] The data acquisition device is configured to: receive multi-channel electrical signals generated by the PVDF piezoelectric film when the composite material structure is impacted by a foreign object, and store data according to a preset rule, including: when the signal amplitudes of two or more channels are greater than a threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and a preset duration, and sent to a remote data center; otherwise, the signal is continuously stored at a second preset frequency and a preset duration, and sent to a remote data center;

[0011] The data center is configured to: receive the electrical signal sent by the data acquisition equipment, extract the characteristic value of the electrical signal, derive the normal operating condition threshold value according to the change law of the characteristic value of the electrical signal, and when the characteristic value of a certain signal exceeds the normal operating condition threshold value, combine the signal and the previous signal to determine whether it is impacted by foreign objects.

[0012] Furthermore, the composite material structure includes a structural body, a flexible sensor is attached to the outer surface of the structural body, an array composed of PVDF piezoelectric films is integrated into a flexible circuit, the outer surface of the flexible sensor is covered with a glass fiber layer, a connector is arranged on the surface of the flexible circuit, and is connected to the data acquisition equipment of the vehicle-mounted host through the connector and cables.

[0013] Furthermore, the structural body is rolled into a cylindrical structure by laying out carbon fiber layers.

[0014] Furthermore, the data acquisition device includes an MCU, a signal amplification module, a positioning module, a communication module and a storage module;

[0015] One end of the signal amplification module is connected to each electrical signal channel, and the other end is connected to the MCU. The positioning module, the communication module and the storage module are respectively connected to the MCU.

[0016] Furthermore, the first preset frequency and the preset duration are 100kHz frequency and 1s duration;

[0017] The second preset frequency and preset duration use a frequency of 2 kHz and a duration of 1 s.

[0018] Furthermore, the data center is configured to: receive electrical signals sent by digital acquisition equipment, calculate the maximum value and root mean square value of the signal within a preset time length, and statistically analyze the change pattern of the maximum value and root mean square value to obtain a normal operating condition threshold; when the maximum value and root mean square value of a certain signal exceed the normal operating condition threshold, filter the signal and previous signals to obtain a filtered signal waveform; when the signal waveform meets the characteristics of foreign object impact, it is determined that the signal may have been impacted by a foreign object.

[0019] In order to solve the above problems, the second aspect of the present invention provides a method for monitoring foreign body impact on a composite material structure, which receives a multi-channel electrical signal generated by a PVDF piezoelectric film when the composite material structure is impacted by a foreign body, stores the data according to preset rules, and derives a normal operating condition threshold value based on the change law of the characteristic value of the electrical signal. When the characteristic value of a certain signal exceeds the normal operating condition threshold value, it is determined whether the structure is impacted by a foreign body by combining the signal and the previous signal, thereby solving the problem that foreign body impact events are difficult to detect during the use of composite material structural components.

[0020] In order to achieve the above object, the present invention adopts the following technical solution:

[0021] A method for monitoring foreign body impact on a composite material structure comprises the following steps:

[0022] When the composite material structure is impacted by a foreign object, the electrical signal generated by the PVDF piezoelectric film is received, and data is stored according to a preset rule. When the signal amplitude of two or more channels is greater than a threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and a preset duration; otherwise, the signal is continuously stored at a second preset frequency and a preset duration;

[0023] Receive the electrical signal sent by the data acquisition equipment, extract the characteristic value of the electrical signal, and derive the normal operating threshold based on the change law of the characteristic value of the electrical signal. When the characteristic value of a certain signal exceeds the normal operating threshold, combine the signal and the previous signal to determine whether it is impacted by foreign objects.

[0024] Furthermore, the electrical signal sent by the digital acquisition device is received, the maximum value and root mean square value of the signal within a preset time length are calculated, and the change pattern of the maximum value and root mean square value is statistically analyzed to obtain the normal operating condition threshold. When the maximum value and root mean square value of a certain signal exceed the normal operating condition threshold, the signal and the previous signal are filtered to obtain a filtered signal waveform. When the signal waveform meets the characteristics of foreign object impact, it is determined that the system may have been impacted by a foreign object.

[0025] Furthermore, the first preset frequency and the preset duration are 100kHz frequency and 1s duration;

[0026] The second preset frequency and preset duration use a frequency of 2 kHz and a duration of 1 s.

[0027] In order to solve the above problems, the third aspect of the present invention provides a composite material structure foreign body impact monitoring system, which uses a PVDF piezoelectric film array flexible sensor and a data acquisition device and system to monitor foreign body impact events, thereby solving the problem that foreign body impact events of composite material structural components are difficult to detect during use. It can effectively ensure the service safety of the structure, reduce the number of inspections and maintenance, and support the transformation from "planned maintenance" to "condition-based maintenance".

[0028] In order to achieve the above object, the present invention adopts the following technical solution:

[0029] A composite material structure foreign body impact monitoring system comprises the composite material structure foreign body impact monitoring device described in the first aspect.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention receives multi-channel electrical signals generated by PVDF piezoelectric film when the composite material structure is impacted by foreign objects, stores data according to preset rules, and obtains the normal working condition threshold according to the change law of the characteristic value of the electrical signal. When the characteristic value of a certain signal exceeds the normal working condition threshold, the signal and the previous signal are combined to determine whether the composite material structure is impacted by foreign objects, thereby solving the problem that foreign object impact events are difficult to detect during the use of composite material structural components, and can effectively ensure the service safety of the structure and reduce the number of inspections and maintenance.

[0032] 2. The present invention adopts a lighter and thinner PVDF piezoelectric film array to replace the piezoelectric ceramic array, which is integrated into a flexible printed circuit board. The flexible printed circuit sensor with integrated PVDF piezoelectric film array is pasted on the outer surface of the carbon fiber ply, which is more sensitive to the impact of foreign objects. At the same time, 1 to 2 layers of glass fiber ply are wrapped on the outside of the sensor. This avoids the risk of introducing defects by burying the sensor between carbon fiber plies and ensures the reliability of the sensor, which will not fall off during application.

[0033] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] Figure 1 Schematic diagram of a composite material structure foreign body impact monitoring device provided by an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of a three-dimensional structure of a composite material provided by an embodiment of the present invention;

[0037] Figure 3 is a schematic diagram of the overall structure of a composite material provided by an embodiment of the present invention;

[0038] Figure 4 It is a structural schematic diagram of a data acquisition device provided by an embodiment of the present invention;

[0039] Figure 5 This is a signal storage and sending mechanism provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0043] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0044] In view of the problem that the composite material structural components mentioned in the background technology are impacted by foreign objects, the existing impact monitoring is difficult to detect foreign object impact events during the use of composite material structural components. The present invention adopts a thinner PVDF piezoelectric film array to replace the piezoelectric ceramic array, which is integrated into a flexible printed circuit board. The flexible printed circuit sensor with the integrated PVDF piezoelectric film array is pasted on the outer surface of the carbon fiber ply, and 1 to 2 layers of glass fiber ply are wrapped on the outside of the sensor; the data acquisition hardware adopts a minimalist design and stores data according to preset rules. When the signal amplitude of more than two channels is greater than the threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and preset duration, and sent to a remote data center, otherwise the signal is continuously stored at a second preset frequency and preset duration, and sent to a remote data center; after the remote data center receives the signal, it uses the maximum value and the root mean square value to make a preliminary judgment on the foreign object impact, and determines whether the structure has been impacted by a foreign object based on whether the filtered signal waveform is similar to the foreign object impact waveform. It solves the problem of difficulty in detecting foreign body impact events during the use of composite structural components, which can effectively ensure the safety of structural service, reduce the number of inspections and maintenance, and support the transformation from "planned maintenance" to "condition-based maintenance".

[0045] Embodiment 1

[0046] like Figure 1 As shown, this embodiment provides a composite material structure foreign body impact monitoring device, including a composite material structure, a data acquisition device and a remote data center; one end of the data acquisition device is connected to the sensor through a connector, and the other end is wirelessly connected to the data center;

[0047] like Figure 2 and Figure 3 As shown, the composite material structure includes a structural body, a flexible sensor is attached to the outer surface of the structural body, and the outer surface of the flexible sensor is covered with a glass fiber layer;

[0048] In this embodiment, the structural body is rolled into a cylindrical structure using carbon fiber layers, and the flexible sensor is attached to the outer surface of the cylinder. The flexible sensor includes an array composed of PVDF piezoelectric film, a flexible circuit and a connector. The array composed of PVDF piezoelectric film is integrated on the flexible circuit. A connector is arranged on the surface of the flexible circuit, and is connected to the data acquisition device of the vehicle-mounted host through the connector and the cable.

[0049] In this embodiment, the flexible circuit is composed of a polyimide substrate and a copper foil, and is formed by attaching the copper foil to the polyimide substrate through etching.

[0050] PVDF piezoelectric film arrays are used to replace piezoelectric ceramic arrays and integrated into flexible printed circuit boards. PVDF piezoelectric film is thinner and lighter than piezoelectric ceramics and is more sensitive to foreign body impact, so it has more application prospects.

[0051] The present invention adheres a flexible printed circuit sensor with an integrated PVDF piezoelectric film array to the outer surface of a carbon fiber ply, and at the same time covers the outside of the sensor with 1 to 2 layers of glass fiber plies, thereby avoiding the risk of introducing defects by embedding the sensor between the carbon fiber plies and ensuring the reliability of the sensor, which will not fall off during application.

[0052] like Figure 4 As shown, the data acquisition device includes an MCU, a signal amplification module, a positioning module, a communication module and a storage module;

[0053] One end of the signal amplification module is connected to each electrical signal channel, and the other end is connected to the MCU. The positioning module, the communication module and the storage module are respectively connected to the MCU.

[0054] Among them, the positioning module uses Beidou positioning to give the current location information, including longitude and latitude and speed, etc.; the communication module is used to transmit locally stored data to the remote data center through the network.

[0055] The signal amplification module is used to amplify the electrical signals of each channel and transmit them to the MCU.

[0056] When a composite material structure is impacted by a foreign object, stress waves are generated on the surface of the structure. Due to the piezoelectric effect, the stress waves cause the PVDF piezoelectric film to generate electrical signals. The electrical signals are collected and stored by the data acquisition device through flexible circuits, connectors and cables. The data acquisition device stores and sends the data to the cloud according to preset rules.

[0057] like Figure 5 The data storage and transmission mechanism is shown. When the data acquisition equipment is powered on, real-time and synchronous data acquisition is carried out at a sampling frequency of 100kHz. When the signal amplitude of more than two channels is greater than the threshold, it can be determined that foreign body impact may have occurred. At this time, the signal is stored at a first preset frequency and preset duration, and sent to the remote data center. After filtering and other processing by the remote data center, it is combined with historical data and other channel data for comprehensive analysis. Otherwise, it is continuously stored at a second preset frequency and preset duration, and sent to the remote data center at preset time intervals for in-depth mining by the remote data center.

[0058] In this embodiment, the first preset frequency and the preset duration are 100kHz and 1s respectively.

[0059] The second preset frequency and preset duration use a frequency of 2kHz and a duration of 1s;

[0060] While ensuring the passive monitoring and service status monitoring functions, the cost of hardware equipment is minimized; due to the limited data processing capability of the MCU, only the MCU on the data acquisition device side is used to perform data processing tasks with low memory consumption, such as judging the signal size;

[0061] Due to the limited storage module capacity and wireless communication bandwidth, the sampling frequency is fixed at 100K, and the storage and wireless communication data are classified and processed. When a foreign object impact is received, the information of the foreign object impact is completely saved at a sampling frequency of 100K and sent to the remote data center. Since the probability of foreign object impact is low, in most cases, the data is stored and sent at 2K. This ensures the functions of foreign object impact and service status monitoring, while minimizing the storage module capacity and wireless communication bandwidth.

[0062] It can be understood that in other embodiments, the preset frequency and the preset duration can be set by those skilled in the art according to specific working conditions, which will not be described in detail here.

[0063] Remote data center: Filter and perform further processing on the data transmitted by wireless communication. According to the signal characteristics, sample offline ground tests to simulate actual service conditions and invert the foreign object impact load to evaluate the residual strength of composite materials, supporting the transition from "planned maintenance" to "condition-based maintenance".

[0064] The remote data center downloads the cloud data in real time or periodically for data processing and analysis.

[0065] After the remote data center receives the signal, it calculates the maximum value and root mean square value of the 1s signal, and statistics the changing rules of the maximum value and root mean square value to obtain the threshold value of normal operating conditions. When the maximum value and root mean square value of a 1s signal exceed the threshold value, the 1s signal and the previous 1s signal are fast Fourier transformed and bandpass filtered to obtain the filtered signal waveform. When the signal waveform meets the characteristics of foreign body impact, it is determined that it may have been impacted by a foreign body. At this time, further offline testing (such as ultrasonic non-destructive testing, etc.) is carried out on the composite material structural components, and the residual strength of the structure is evaluated.

[0066] Embodiment 2

[0067] This embodiment provides a method for monitoring foreign body impact on a composite material structure, comprising the following steps:

[0068] When the composite material structure is impacted by a foreign object, the electrical signal generated by the PVDF piezoelectric film is received, and data is stored according to a preset rule. When the signal amplitude of two or more channels is greater than a threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and a preset duration; otherwise, the signal is continuously stored at a second preset frequency and a preset duration;

[0069] Receive the electrical signal sent by the data acquisition equipment, extract the characteristic value of the electrical signal, and derive the normal operating threshold based on the change law of the characteristic value of the electrical signal. When the characteristic value of a certain signal exceeds the normal operating threshold, combine the signal and the previous signal to determine whether it is impacted by foreign objects.

[0070] Furthermore, the electrical signal sent by the digital acquisition device is received, the maximum value and root mean square value of the signal within a preset time length are calculated, and the change pattern of the maximum value and root mean square value is statistically analyzed to obtain the normal operating condition threshold. When the maximum value and root mean square value of a certain signal exceed the normal operating condition threshold, the signal and the previous signal are filtered to obtain a filtered signal waveform. When the signal waveform meets the characteristics of foreign object impact, it is determined that the system may have been impacted by a foreign object.

[0071] In this embodiment, the first preset frequency and the preset duration are 100kHz and 1s respectively;

[0072] The second preset frequency and preset duration use a frequency of 2 kHz and a duration of 1 s.

[0073] Embodiment 3

[0074] This embodiment provides a composite material structure foreign body impact monitoring system, including the composite material structure foreign body impact monitoring device described in the first embodiment.

[0075] Based on the same inventive concept, this embodiment provides a composite material structure foreign object impact monitoring device corresponding to a composite material structure foreign object impact monitoring device. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned method in Example 1, the implementation of the system can refer to the implementation of the device, and the repeated parts will not be repeated.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A composite material structure foreign body impact monitoring device, characterized in that: It includes a composite material structure, a data acquisition device and a data center, wherein a sensor composed of a PVDF piezoelectric film is arranged on the composite material structure, and the data acquisition device is connected to the sensor and the data center respectively; The data acquisition device is configured to: receive multi-channel electrical signals generated by the PVDF piezoelectric film when the composite material structure is impacted by a foreign object, and store data according to a preset rule, including: when the signal amplitudes of two or more channels are greater than a threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and a preset duration, and sent to a remote data center; otherwise, the signal is continuously stored at a second preset frequency and a preset duration, and sent to a remote data center; The data center is configured to: receive the electrical signal sent by the data acquisition equipment, extract the characteristic value of the electrical signal, derive the normal operating condition threshold value according to the change law of the characteristic value of the electrical signal, and when the characteristic value of a certain signal exceeds the normal operating condition threshold value, combine the signal and the previous signal to determine whether it is impacted by foreign objects.

2. A composite material structure foreign body impact monitoring device as claimed in claim 1, characterized in that: The composite material structure includes a structural body, a flexible sensor is pasted on the outer surface of the structural body, an array composed of PVDF piezoelectric films is integrated on a flexible circuit, the outer surface of the flexible sensor is covered with a glass fiber layer, a connector is arranged on the surface of the flexible circuit, and is connected to the data acquisition equipment of the vehicle-mounted host through the connector and cables.

3. A composite material structure foreign body impact monitoring device as claimed in claim 2, characterized in that: The structural body is rolled into a cylindrical structure by laying out carbon fiber layers.

4. A composite material structure foreign body impact monitoring device as claimed in claim 1, characterized in that: The data acquisition device includes an MCU, a signal amplification module, a positioning module, a communication module and a storage module; One end of the signal amplification module is connected to each electrical signal channel, and the other end is connected to the MCU. The positioning module, the communication module and the storage module are respectively connected to the MCU.

5. A composite material structure foreign body impact monitoring device as claimed in claim 1, characterized in that: The first preset frequency and preset duration use a frequency of 100kHz and a duration of 1s; The second preset frequency and preset duration use a frequency of 2 kHz and a duration of 1 s.

6. A composite material structure foreign body impact monitoring device as claimed in claim 1, characterized in that: The data center is configured to: receive the electrical signal sent by the data acquisition equipment, calculate the maximum value and root mean square value of the signal within a preset time length, and count the change rules of the maximum value and root mean square value to obtain the normal operating condition threshold. When the maximum value and root mean square value of a certain signal exceed the normal operating condition threshold, filter the signal and the previous signal to obtain a filtered signal waveform. When the signal waveform meets the characteristics of foreign object impact, it is determined that it may have been impacted by a foreign object.

7. A method for monitoring foreign body impact on composite material structure, characterized in that: The steps include: When the composite material structure is impacted by a foreign object, the electrical signal generated by the PVDF piezoelectric film is received, and data is stored according to a preset rule. When the signal amplitude of two or more channels is greater than a threshold, it is determined that a foreign object impact occurs, and the signal is continuously stored at a first preset frequency and a preset duration; otherwise, the signal is continuously stored at a second preset frequency and a preset duration; Receive the electrical signal sent by the data acquisition equipment, extract the characteristic value of the electrical signal, and derive the normal operating threshold based on the change law of the characteristic value of the electrical signal. When the characteristic value of a certain signal exceeds the normal operating threshold, combine the signal and the previous signal to determine whether it is impacted by foreign objects.

8. A composite material structure foreign body impact monitoring method as claimed in claim 7, characterized in that: Receive the electrical signal sent by the data acquisition equipment, calculate the maximum value and root mean square value of the signal within the preset time length, and statistically analyze the change pattern of the maximum value and root mean square value to obtain the normal operating threshold. When the maximum value and root mean square value of a certain signal exceed the normal operating threshold, filter the signal and the previous signal to obtain the filtered signal waveform. When the signal waveform meets the characteristics of foreign object impact, it is determined that it may have been impacted by a foreign object.

9. A composite material structure foreign body impact monitoring method as claimed in claim 7, characterized in that: The first preset frequency and preset duration use a frequency of 100kHz and a duration of 1s; The second preset frequency and preset duration use a frequency of 2 kHz and a duration of 1 s.

10. A composite material structure foreign body impact monitoring system, characterized in that: It comprises a composite material structure foreign body impact monitoring device as described in any one of claims 1-6.

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