Composite material structure impact positioning method and device based on variational mode decomposition

Abstract

The invention provides a composite material structure impact positioning method and device based on variational mode decomposition, and belongs to the technical field of composite material structure health monitoring, and the method comprises the steps: obtaining a to-be-detected composite material structure, determining the modal parameters of the to-be-detected composite material structure through an experimental modal analysis method, and determining the modal parameters of the to-be-detected composite material structure according to the modal parameters of the to-be-detected composite material structure; establishing a modal shape database based on the modal parameters, acquiring a strain response signal corresponding to an impact force applied by a single FBG sensor to the composite material structure to be measured, performing variational mode decomposition on the strain response signal to obtain a modal response component, performing exponential fitting on the modal response component to obtain a modal constant vector, and performing modal shape analysis on the modal constant vector to obtain a modal shape database; and performing cosine similarity measurement on the modal shape database and the modal constant vector to obtain impact positioning information of the composite material structure. The technical problems of high sampling cost and complex calculation in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material structure health monitoring, and in particular to a composite material structure impact positioning method and device based on variational modal decomposition. Background Art

[0002] With the continuous development of science and technology, composite materials have been widely used in aviation, aerospace, shipbuilding, energy and other fields due to their large stiffness-to-mass ratio and high strength-to-mass ratio. However, due to the poor shear resistance of composite materials, they are prone to imperceptible impact damage (BVID) when subjected to impact events. This internal damage will gradually spread with the increase of service time until it causes the destruction of the entire structure. However, due to the limitations of the sensor installation position, these impact loads are often not directly measured. The damage caused by the impact event cannot be detected in real time by traditional non-destructive testing methods such as infrared imaging and ultrasonic scanning. Therefore, using the vibration response of the structure (such as strain, displacement, and acceleration) to identify the impact load of the structure in real time has become one of the most popular methods.

[0003] In the current research on the location of impact loads at home and abroad, the commonly used impact location methods are the time-of-flight method, the regularization method, and the pattern matching method. Among them, the time-of-flight method uses the arrival time of the traveling wave caused by the impact to identify the impact load. This method often requires redundant sensor arrays and extremely high sampling frequencies (not less than 100KHz). The sampling cost is extremely high, and when the waves propagate in the composite material, they will be affected by various factors such as reflection and refraction, which makes it quite complicated to accurately determine the propagation characteristics of the wave in advance; some regularization methods (such as Tikhonv regularization method and sparse regularization method) can accurately and synchronously identify the position of the impact load and the time history of the load, but the huge deconvolution model will consume a lot of computing time; in addition, the impact force identification method based on modal analysis and pattern matching technology has an efficient impact load location speed, but lacks an effective algorithm for extracting modal constants from the measurement data. Therefore, there are technical problems of high sampling cost and complex calculation in the existing technology. Summary of the invention

[0004] In view of this, it is necessary to provide a composite material structure impact location method and device based on variational modal decomposition to solve the technical problems of high sampling cost and complex calculation in the prior art.

[0005] In order to solve the above technical problems, on the one hand, the present invention provides a composite material structure impact location method based on variational mode decomposition, comprising: Acquire the composite material structure to be tested, and determine the modal parameters of the composite material structure to be tested by experimental modal analysis method; Establish a modal vibration shape database based on modal parameters; Obtaining the strain response signal corresponding to the impact force applied by a single FBG sensor to the composite material structure to be tested; Perform variational modal decomposition on the strain response signal to obtain modal response components; Perform exponential fitting on the modal response components to obtain the modal constant vector; The cosine similarity measurement is performed on the modal vibration database and the modal constant vector to obtain the impact location information of the composite structure.

[0006] In a possible implementation, the modal parameters of the composite material structure to be tested include: The natural frequency, damping coefficient, displacement mode shape at the candidate impact point and strain mode shape at the candidate impact point of the composite material structure to be tested.

[0007] In a possible implementation, establishing a modal vibration shape database based on modal parameters includes: The modal vibration shape database is established based on the modal parameters and the order N of the modal constants is determined.

[0008] In a possible implementation, performing variational modal decomposition on the strain response signal to obtain modal response components includes: Under the determined order N of the modal constant, the strain response signal is subjected to variational modal decomposition to obtain the first N-order modal response components.

[0009] In a possible implementation, performing exponential fitting on the modal response components to obtain the modal constant vector includes: Perform exponential fitting on the first N order modal response components to obtain the modal constant vector.

[0010] In a possible implementation, performing exponential fitting on the first N-order modal response components to obtain a modal constant vector includes: The modal constant vector is obtained by performing exponential fitting of the least square method on the first N modal response components.

[0011] In a possible implementation, performing cosine similarity measurement on the modal vibration shape database and the modal constant vector to obtain impact location information of the composite material structure includes: The cosine similarity measurement is performed on the modal vibration database and the modal constant vector based on the similarity matrix to obtain the impact location information of the composite structure.

[0012] On the other hand, the present invention also provides a composite material structure impact positioning device based on variational modal decomposition, comprising: An acquisition module is used to acquire the composite material structure to be tested and determine the modal parameters of the composite material structure to be tested by an experimental modal analysis method; A modal vibration database module is used to establish a modal vibration database based on modal parameters; A strain response signal module is used to obtain a strain response signal of an impact force applied by a single FBG sensor to the composite material structure to be tested; The modal response component module is used to perform variational modal decomposition on the strain response signal to obtain the modal response components; The modal constant vector module is used to perform exponential fitting on the modal response components to obtain the modal constant vector; The positioning module is used to perform cosine similarity measurement on the modal vibration database and the modal constant vector to obtain the impact positioning information of the composite material structure.

[0013] On the other hand, the present invention also provides an electronic device, including a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps of the composite material structure impact location method based on variational modal decomposition in any of the above implementations.

[0014] On the other hand, the present invention also provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps of the composite material structure impact location method based on variational modal decomposition described in any of the above-mentioned implementations.

[0015] The beneficial effects of the present invention are as follows: the composite structure impact location method based on variational modal decomposition provided by the present invention comprises: obtaining the composite structure to be tested, and determining the modal parameters of the composite structure to be tested by an experimental modal analysis method, establishing a modal vibration shape database based on the modal parameters, and the purpose of this is to establish the modal vibration shape database; obtaining the strain response signal corresponding to the impact force applied by a single FBG sensor to the composite structure to be tested, and the purpose of this is to obtain the strain response signal corresponding to the impact force applied to the composite structure to be tested by only using a single FBG sensor; performing variational modal decomposition on the strain response signal to obtain modal response components, performing exponential fitting on the modal response components to obtain modal constant vectors, performing cosine similarity measurement on the modal vibration shape database and the modal constant vector, and obtaining composite structure impact location information, and the purpose of this is to solve the problem of accurate identification of the impact position of the FBG sensor on the model structure at a low sampling rate through the VMD method, and achieve the purpose of reducing sampling costs and simplifying the calculation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments 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 work.

[0017] Figure 1 A schematic flow chart of an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 2 A flow chart of an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 3 A schematic diagram of a CFRP (Carbon Fiber Reinforced Plastic) plate and candidate impact points and a FBG (Fiber Bragg Grating) sensor position in one embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 4 A displacement mode vibration result diagram of each candidate impact point of a CFRP plate obtained by experimental modal analysis of an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 5 A graph showing the impact load location results of a CFRP plate according to an embodiment of the composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 6 A schematic diagram of a CFRP plate, candidate impact points and FBG sensor positions in one embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention; Figure 7 An embodiment of the composite material structure impact positioning method based on variational modal decomposition provided by the present invention is used to position the impact load of the CFRP plate under different excitation conditions, and a positioning result diagram of the group with deviation identification; Figure 8 A schematic structural diagram of an embodiment of a composite material structure impact positioning device based on variational modal decomposition provided by the present invention; Fig. 9 A schematic structural diagram of an embodiment of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0020] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0021] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] The present invention provides a composite material structure impact location method, device, electronic device and storage medium based on variational modal decomposition, which are respectively described below.

[0024] Figure 1 A schematic diagram of an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention and Figure 2 A flow chart of an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention includes: S101, obtaining a composite material structure to be tested, and determining modal parameters of the composite material structure to be tested by an experimental modal analysis method; S102, establishing a modal vibration shape database based on modal parameters; S103, obtaining a strain response signal corresponding to the impact force applied by a single FBG sensor to the composite material structure to be tested; S104, performing variational modal decomposition on the strain response signal to obtain modal response components; S105, performing exponential fitting on the modal response components to obtain a modal constant vector; S106. Perform cosine similarity measurement on the modal vibration shape database and the modal constant vector to obtain impact location information of the composite material structure.

[0025] It can be understood that in step S101, the modal parameters of the composite material structure to be tested are determined by experimental modal analysis or finite element analysis.

[0026] In step S102, a candidate impact point modal vibration shape database is established based on the determined modal parameters of the composite material structure to be tested.

[0027] In steps S103, S104 and S105, the strain response signal of the unknown impact load is measured and the signal is obtained by using variational mode decomposition based on the modal superposition principle. N The uncorrected modal constants are then calculated using exponential fitting and the least squares method.

[0028] In step S106, the uncorrected modal constant vector calculated in the above steps and each column of the modal vibration shape database are evaluated by cosine similarity, and finally the real action position of the unknown impact load is determined among all candidate impact points.

[0029] It can be further understood that the present invention relates to a new method for identifying impact loads using modal acceleration response, which is used to improve the monitoring efficiency of impact events and reduce sampling costs. The method includes the following steps: 1) Determine the modal parameters of the composite structure to be tested by experimental modal analysis or finite element analysis, and establish a modal vibration mode database of candidate impact points. 2) Select measurement points according to the modal analysis results, and the measurement points should try to avoid the low-order modal nodes of the structure. 3) Determine the order N of the uncorrected modal constants to be extracted according to the modal analysis results. 4) Measure the strain response signal of the unknown impact load and use variational modal decomposition based on the modal superposition principle to obtain the first N-order modal response components of the signal, and then use exponential fitting and least squares method to calculate the uncorrected modal constants. 5) Perform cosine similarity evaluation on the calculated uncorrected modal constant vector and each column of the modal vibration mode database, and finally determine the true action position of the unknown impact load among all candidate impact points. The experimental verification results on the cantilever plate show that the proposed method can accurately and efficiently identify the impact load with only the measurement data of a single accelerometer.

[0030] It should be further explained that the present invention proposes a variational mode decomposition (VMD) based impact location method, which solves the problem of accurately identifying the impact position of the model structure by the FBG sensor at a low sampling rate (e.g., 5kHz) under the premise of using only a single FBG sensor to sample at a low sampling rate (e.g., 5kHz) by the VMD (variational mode decomposition) method. The technical solution proposed in the present invention includes an impact positioning method based on variational modal decomposition, which divides the composite material results into a network, determines the modal parameters of the structure to be tested through experimental modal analysis or finite element analysis, sets each network center as a candidate impact point and establishes a modal vibration shape database of the candidate impact points; a single FBG sensor is pasted on the surface of the composite material structure to monitor the impact response signal of the material surface in real time; the response signal of the FBG sensor under an unknown impact load is used as a test signal, and the uncorrected modal constant in the test signal is extracted by using variational modal decomposition; the impact area is determined based on the calculation result of the cosine similarity between the uncorrected modal constant extracted from the test signal and the modal vibration shape database; this method is not only much lower than the time positioning method in sampling frequency, but also much smaller than the regularization method in data volume, so it can achieve impact positioning under a single FBG sensor and low frequency, effectively shortening the experimental cycle and having universal applicability.

[0031] It should be further explained that the present invention provides a composite material structure impact location method based on variational modal decomposition, which has the following beneficial effects: 1. The impact load locating method provided in the present disclosure proposes for the first time to use variational modal decomposition to achieve rapid impact load locating.

[0032] 2. Compared with the traditional impact load location method based on uncorrected modal constants and regularization methods, the method provided by the present disclosure significantly reduces the computational burden and greatly improves the efficiency of impact load location of composite materials.

[0033] 3. The impact load positioning method provided by the present disclosure does not require a complex sensor array and a high sampling frequency, and can achieve impact load positioning by using only a single FBG sensor with a low sampling frequency.

[0034] In some embodiments of the present invention, the modal parameters of the composite material structure to be tested include: The natural frequency, damping coefficient, displacement mode shape at the candidate impact point and strain mode shape at the candidate impact point of the composite material structure to be tested.

[0035] It can be understood that the experimental modal analysis or finite element analysis is performed on the composite material structure to obtain the natural frequency, damping coefficient, displacement mode shape and strain mode shape at the candidate impact point of the structure.

[0036] Figure 3A schematic diagram of a CFRP (Carbon Fiber Reinforced Plastic) plate and candidate impact points and FBG (Fiber Bragg Grating) sensor positions according to an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention Figure 4 The displacement modal vibration result diagram at each candidate impact point of the CFRP plate obtained by experimental modal analysis of an embodiment of the composite material structure impact positioning method based on variational modal decomposition provided by the present invention includes: The modal vibration shape database is established based on the modal parameters and the order N of the modal constants is determined.

[0037] It can be understood that the modal vibration database Φ is established based on the modal parameters: .

[0038] It should be further explained that when selecting measuring points based on the modal analysis results, the measuring points should try to avoid the low-order modal nodes of the structure.

[0039] It can be further understood that the impact load is localized using a CFRP (carbon fiber reinforced plastic) composite material plate structure. Figure 3 shown.

[0040] A CFRP composite plate with T300 carbon fiber prepreg and a ply order of [0 / 90]5s was used. Ten degrees of freedom were selected as candidate impact positions. The upper bottom, lower bottom, height and thickness of the CFRP plate were 150 mm, 200 mm, 500 mm and 3 mm respectively. The FBG pasting position was as follows: Figure 3 As shown. One end of the plate is clamped and mounted on a vibration isolation platform, and a hammer model COINV INV9311 is used to apply an impact load. The central wavelength of the FBG sensor is 1558nm. It is attached to the surface coordinates (50mm, 50mm) of the CFRP plate using modified acrylic structural adhesive. The strain response signal is recorded using a Gator high-speed demodulator (1-19.2kHz) with a sampling frequency of 5kHz. The specific implementation steps are as follows: Install the test bench and perform experimental modal analysis on the metal plate to be tested to determine the natural frequency, damping coefficient, strain modal vibration shape at the measuring point, and other factors. Figure 3 The displacement mode shape at the candidate impact point is shown in Figure 4 shown.

[0041] In some embodiments of the present invention, performing variational modal decomposition on the strain response signal to obtain modal response components includes: Under the determined order N of the modal constant, the strain response signal is subjected to variational modal decomposition to obtain the first N-order modal response components.

[0042] It is understandable that the order of the modal constants N The value range should be between 2 and 9, determined based on experience.

[0043] In some embodiments of the present invention, performing exponential fitting on the modal response components to obtain the modal constant vector includes: Perform exponential fitting on the first N order modal response components to obtain the modal constant vector.

[0044] It can be understood that the specific steps to obtain the modal constant vector are as follows: Step 1: Measure the strain response signal of the unknown impact load through the FBG sensor at the measuring point.

[0045] Step 2: Based on the modal superposition principle, use variational modal decomposition to obtain the first N modal response components of the signal:

[0046] Where x(t) is the strain response signal and gj(t) is the j-th modal response component.

[0047] Step 3: Based on the calculation results of step 2, obtain the modal response components of each order of the signal:

[0048] Where f is the excitation force energy, φj(l) is the j-th strain mode of the measuring point l, φj(p) is the j-th displacement mode of the unknown impact point p, ξj, ωj and ωd,j are the j-th damping ratio, undamped natural frequency and damped natural frequency of the structure, respectively.

[0049] in: .

[0050] Step 4: Based on the calculation results in Step 3, use exponential fitting and least squares method to calculate the uncorrected modal constant fϕ*(p).

[0051] in, .

[0052] In some embodiments of the present invention, performing exponential fitting on the first N order modal response components to obtain the modal constant vector includes: The modal constant vector is obtained by performing exponential fitting of the least square method on the first N modal response components.

[0053] Understandably, Figure 5A graph showing the impact load location results of a CFRP plate according to an embodiment of the composite material structure impact location method based on variational modal decomposition provided by the present invention, Figure 6 A schematic diagram of a CFRP plate, candidate impact points and FBG sensor positions according to an embodiment of a composite material structure impact location method based on variational modal decomposition provided by the present invention Figure 7 An embodiment of the composite material structure impact positioning method based on variational modal decomposition provided by the present invention positions the impact load of the CFRP plate under different excitation conditions, and a positioning result diagram of the group with deviation identification includes: The cosine similarity measurement is performed on the modal vibration database and the modal constant vector based on the similarity matrix to obtain the impact location of the composite structure.

[0054] It can be understood that the specific calculation formula of the cosine similarity metric is as follows:

[0055] in, .

[0056] The grid position of the element whose cosine similarity is closest to 1 is selected as the prediction result of the unknown load position.

[0057] It can be further understood that in Figure 5 The ten bar graphs in the figure represent the cosine similarity analysis results of the uncorrected modal constant vector and the modal vibration shape database when the impact load is located at candidate impact points 1 to 10, and the impact load position determined by this is marked in red. The cosine similarity index value at the actual impact position in the impact position identification is greater than the index value at other degrees of freedom, indicating that this method has excellent impact location capability.

[0058] It can be further understood that in Figure 6 It is a schematic diagram of the CFRP plate and the candidate impact points and FBG sensor locations.

[0059] It can be further understood that in Figure 7 In the figure, black five-pointed stars represent correct recognition, red five-pointed stars represent biased recognition, and red arrows point to the predicted positions.

[0060] Repeat the above steps. The recognition results are shown in Table 1.

[0061] Table 1 Recognition results under incentive conditions

[0062] According to Table 1, Figure 5 and Figure 7From the results in Figure 1, it can be concluded that the disclosed method has a high success rate in impact load positioning under noise-free conditions. Even under noise conditions, the positioning accuracy rate reaches 92.14%. For those impacts that are not accurately identified, the misidentification points are still very close to their actual positions. Therefore, the disclosed method has superior and robust impact load positioning capabilities.

[0063] Figure 8 A schematic structural diagram of an embodiment of a composite material structure impact positioning device based on variational modal decomposition provided by the present invention comprises: An acquisition module 801 is used to acquire a composite material structure to be tested, and determine modal parameters of the composite material structure to be tested by an experimental modal analysis method; A modal vibration shape database module 802 is used to establish a modal vibration shape database based on modal parameters; The strain response signal module 803 is used to obtain the strain response signal of the impact force applied by a single FBG sensor to the composite material structure to be tested; The modal response component module 804 is used to perform variational modal decomposition on the strain response signal to obtain modal response components; A modal constant vector module 805 is used to perform exponential fitting on the modal response components to obtain a modal constant vector; The positioning module 806 is used to perform cosine similarity measurement on the modal vibration shape database and the modal constant vector to obtain impact positioning information of the composite material structure.

[0064] The composite material structure impact positioning device 800 based on variational modal decomposition provided in the above embodiment can implement the technical solution described in the above embodiment of the composite material structure impact positioning method based on variational modal decomposition. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above embodiment of the composite material structure impact positioning method based on variational modal decomposition, which will not be repeated here.

[0065] like Fig. 9 As shown, the present invention also provides an electronic device 900. The electronic device 900 includes a processor 901, a memory 902 and a display 903. Fig. 9 Only some components of the electronic device 900 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0066] In some embodiments, the processor 901 may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 902, such as the composite material structure impact location method based on variational modal decomposition in the present invention.

[0067] In some embodiments, the processor 901 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 901 may be local or remote. In some embodiments, the processor 901 may be implemented in a cloud platform. In one embodiment, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0068] In some embodiments, the memory 902 may be an internal storage unit of the electronic device 900, such as a hard disk or memory of the electronic device 900. In other embodiments, the memory 902 may also be an external storage device of the electronic device 900, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the electronic device 900.

[0069] Furthermore, the memory 902 may include both an internal storage unit of the electronic device 900 and an external storage device. The memory 902 is used to store application software installed in the electronic device 900 and various data.

[0070] In some embodiments, the display 903 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 903 is used to display information on the electronic device 900 and to display a visual user interface. The components 901-903 of the electronic device 900 communicate with each other via a system bus.

[0071] In one embodiment, when the processor 901 executes the composite material structure impact location program based on variational modal decomposition in the memory 902, the following steps may be implemented: Acquire the composite material structure to be tested, and determine the modal parameters of the composite material structure to be tested by experimental modal analysis method; Establish a modal vibration shape database based on modal parameters; Obtaining the strain response signal corresponding to the impact force applied by a single FBG sensor to the composite material structure to be tested; Perform variational modal decomposition on the strain response signal to obtain modal response components; Perform exponential fitting on the modal response components to obtain the modal constant vector; The cosine similarity measurement is performed on the modal vibration database and the modal constant vector to obtain the impact location information of the composite structure.

[0072] It should be understood that: when the processor 901 executes the composite material structure impact location program based on variational modal decomposition in the memory 902, in addition to the above functions, other functions can also be realized. For details, please refer to the description of the corresponding method embodiment above.

[0073] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 900 mentioned, and the electronic device 900 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 900 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0074] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions of the composite material structure impact positioning method based on variational modal decomposition provided in the above-mentioned method embodiments.

[0075] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0076] The above is a detailed introduction to the composite material structure impact positioning method, device, electronic device and storage medium based on variational modal decomposition provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A composite material structure impact location method based on variational modal decomposition, characterized in that: include: Acquire the composite material structure to be tested, and determine the modal parameters of the composite material structure to be tested by experimental modal analysis method; Establish a modal vibration shape database based on modal parameters; Obtaining the strain response signal corresponding to the impact force applied by a single FBG sensor to the composite material structure to be tested; Perform variational modal decomposition on the strain response signal to obtain modal response components; Perform exponential fitting on the modal response components to obtain the modal constant vector; The cosine similarity measurement is performed on the modal vibration database and the modal constant vector to obtain the impact location information of the composite structure.

2. The composite material structure impact location method based on variational modal decomposition according to claim 1, characterized in that: The modal parameters of the composite material structure to be tested include: The natural frequency, damping coefficient, displacement mode shape at the candidate impact point and strain mode shape at the candidate impact point of the composite material structure to be tested.

3. The composite material structure impact location method based on variational modal decomposition according to claim 1, characterized in that: The step of establishing a modal vibration shape database based on modal parameters comprises: The modal vibration shape database is established based on the modal parameters and the order N of the modal constants is determined.

4. The composite material structure impact location method based on variational modal decomposition according to claim 1 or 3, characterized in that: The variational modal decomposition of the strain response signal to obtain the modal response component includes: Under the determined order N of the modal constant, the strain response signal is subjected to variational modal decomposition to obtain the first N-order modal response components.

5. The composite material structure impact location method based on variational modal decomposition according to claim 1 or 4, characterized in that: The exponential fitting of the modal response components is performed to obtain the modal constant vector, including: Perform exponential fitting on the first N order modal response components to obtain the modal constant vector.

6. The composite material structure impact location method based on variational modal decomposition according to claim 5, characterized in that: The exponential fitting is performed on the first N order modal response components to obtain the modal constant vector, including: The modal constant vector is obtained by performing exponential fitting of the least square method on the first N modal response components.

7. The composite material structure impact location method based on variational modal decomposition according to claim 1, characterized in that: The method of performing cosine similarity measurement on the modal vibration shape database and the modal constant vector to obtain impact location information of the composite material structure includes: The cosine similarity measurement is performed on the modal vibration database and the modal constant vector based on the similarity matrix to obtain the impact location information of the composite structure.

8. A composite material structure impact positioning device based on variational modal decomposition, characterized in that: include: An acquisition module is used to acquire the composite material structure to be tested and determine the modal parameters of the composite material structure to be tested by an experimental modal analysis method; A modal vibration database module is used to establish a modal vibration database based on modal parameters; A strain response signal module is used to obtain a strain response signal of an impact force applied by a single FBG sensor to the composite material structure to be tested; The modal response component module is used to perform variational modal decomposition on the strain response signal to obtain the modal response components; The modal constant vector module is used to perform exponential fitting on the modal response components to obtain the modal constant vector; The positioning module is used to perform cosine similarity measurement on the modal vibration database and the modal constant vector to obtain the impact positioning information of the composite material structure.

9. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the composite material structure impact location method based on variational modal decomposition as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps of the composite material impact location method based on variational modal decomposition as described in any one of claims 1 to 7.

Images