A composite material damage identification method, system, medium and equipment based on ultrasonic guided waves

Abstract

The present invention relates to the field of structural detection technology, and in particular to a composite material damage identification method, system, medium and equipment based on ultrasonic guided waves. Compared with the existing technology, the composite material damage identification method, system, medium and equipment based on ultrasonic guided waves provided by the present invention construct a WAET three-dimensional surface mapping model to obtain a three-dimensional coupling mapping relationship between wave number, waveguide angle and actual effective thickness, fully considering the structural characteristics of the composite material consisting of a laminated structure of multiple layers laid in anisotropic directions, avoiding the significant anisotropy of propagation characteristics such as wave velocity, wave number, group velocity at different angles, resulting in significant differences in intensity and shape of the same defect in different propagation directions, thereby improving imaging consistency.

Description

Technical Field

[0001] The present invention relates to the technical field of structural detection, and in particular to a composite material damage identification method, system, medium and equipment based on ultrasonic guided waves. Background Art

[0002] With the widespread application of advanced composite materials in fields such as aerospace, their advantages of lightweight structures and high specific strength are significant. However, composite structures are prone to micro-scale defects such as delamination, debonding, matrix cracking, impact damage, and inclusions during long-term service. These defects are often invisible on the surface, develop irreversibly, and spread uncontrollably. If not identified in time, they will seriously threaten structural safety and service reliability.

[0003] Currently, nondestructive testing methods for material structures primarily include ultrasonic C-scan, ultrasonic guided waves, X-rays, thermal imaging, and acoustic emission. Ultrasonic guided waves are widely used in this field due to their advantages, such as long propagation distance, wide coverage area, and sensitivity to delamination defects. However, existing ultrasonic guided wave identification technology still faces numerous challenges when applied to composite materials.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase understanding of the overall background of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned existing ultrasonic guided wave identification technology in identifying composite material structure damage, the present invention provides a composite material damage identification method based on ultrasonic guided waves, comprising the following steps:

[0006] Collect the initial guided wave signal from the material under test, convert the initial guided wave signal into a frequency domain wave field signal and filter the corresponding single frequency field wave according to the main frequency to obtain a single frequency frequency domain field wave signal;

[0007] Process the single-frequency frequency domain field wave signal, calculate the phase space gradient, and construct the spatial wave number field based on the phase space gradient;

[0008] A WAET three-dimensional surface mapping model is constructed according to the property information of the tested material. The spatial wavenumber field is combined with the WAET three-dimensional surface mapping model to construct an effective thickness map, and the damage information is obtained through the effective thickness map.

[0009] Furthermore, the initial waveguide signal is three-dimensional out-of-plane displacement field data .

[0010] Furthermore, the step of converting the initial waveguide signal into a frequency domain wave field signal and filtering the corresponding single frequency field wave according to the main frequency to obtain the single frequency frequency domain field wave signal comprises the following steps:

[0011] Three-dimensional out-of-plane displacement field data Perform three-dimensional Fourier transform to obtain frequency domain wave field signal ;

[0012] Wavefield signal in the frequency domain Filter out the single frequency field wave signal corresponding to the main frequency .

[0013] Furthermore, the processing of the single-frequency frequency domain field wave signal, calculating the phase space gradient, and constructing the spatial wave number field according to the phase space gradient comprises the following steps:

[0014] For single frequency domain field wave signal Apply Rees transform to extract 、 The complex spatial gradient component of the direction, and then the phase field is calculated by the angle ;

[0015] Phase field Implement path-tracing unwrapping to obtain a continuous phase field ;

[0016] Calculation of continuous phase field by central difference method spatial gradients;

[0017] According to the continuous phase field Constructing spatial wave number field based on spatial gradient .

[0018] Furthermore, the spatial wave number field Through the continuous phase field The first-order gradient modulus is constructed, and the spatial partial derivative is approximated using the central difference value as follows:

[0019]

[0020] Then the spatial wave number field Expressed as:

[0021]

[0022] in, 、 The continuous phase field is 、 The spatial gradient of the direction, 、 The adjacent sampling points are 、 Spatial spacing in direction.

[0023] Furthermore, constructing the WAET three-dimensional surface mapping model according to the property information of the material under test comprises the following steps:

[0024] The wave number-angle dispersion curve set at multiple key effective thicknesses in the material under test is calculated using the semi-analytical finite element method. ;

[0025] Based on a collection of wavenumber-angle dispersion curves at multiple key effective thicknesses , a WAET three-dimensional surface mapping model of wave number-angle-effective thickness was established through cubic spline interpolation ;

[0026] in, is the propagation direction of the guided wave, is the set of key effective thicknesses, Key effective thickness To the corresponding wave number mapping function, is the actual effective thickness in the waveguide propagation direction and at the spatial sampling point The mapping function from the two corresponding wave numbers.

[0027] Furthermore, the method of combining the spatial wavenumber field with the WAET three-dimensional surface mapping model to construct an effective thickness map and obtaining damage information through the effective thickness map includes the following steps:

[0028] The spatial wave number field Combined with WAET 3D surface mapping model Reflect the actual effective thickness ;

[0029] The actual effective thickness of each The effective thickness map is constructed by color processing according to the spatial coordinates of the spatial sampling points ;

[0030] Through the effective thickness diagram The damage information is obtained, where the damage information at least includes a damage location, a damage outline, and a damage depth.

[0031] Furthermore, the present invention also provides a composite material damage identification system based on ultrasonic guided waves, which is used to implement the above-mentioned composite material damage identification method based on ultrasonic guided waves. The composite material damage identification system based on ultrasonic guided waves includes an acquisition module and a signal processing and algorithm module.

[0032] Furthermore, the present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer is executed by a processor, the computer implements the above-mentioned composite material damage identification method based on ultrasonic guided waves.

[0033] Furthermore, the present invention also provides a computer device comprising at least one processor and a memory communicatively connected to the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the processor to perform the above-mentioned composite material damage identification method based on ultrasonic guided waves.

[0034] Based on the above, the present invention provides a composite material damage identification method, system, medium and equipment based on ultrasonic guided waves. Compared with the existing technology, the WAET algorithm is used to construct a WAET three-dimensional mapping model and a three-dimensional mapping surface, and a three-dimensional coupling mapping relationship between the wave number, the waveguide angle and the actual effective thickness is obtained. The structural characteristics of the composite material composed of a laminated structure of multiple layers laid in anisotropic directions are fully considered, and the propagation characteristics such as wave velocity, wave number, group velocity, etc. at different angles are avoided. The significant anisotropy shows that the same defect presents significant differences in intensity and shape in different propagation directions, thereby improving imaging consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. The positional relationships described in the drawings in the following description are based on the orientation of the components in the drawings unless otherwise specified.

[0036] Figure 1 A schematic flow chart of a composite material damage identification method based on ultrasonic guided waves provided in one embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the construction process of a WAET three-dimensional surface mapping model provided by one embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the wave number field at different incident angles in a simulation experiment provided by the present invention;

[0039] Figure 4 This is a schematic diagram of damage identification results in a simulation experiment provided by the present invention. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variations thereof all mean "at least including".

[0042] Because most composite materials are composed of multiple layers laid in anisotropically, ultrasonic guided waves exhibit significant anisotropy in their propagation characteristics, such as wave velocity, wave number, and group velocity, in different directions. This can cause the same defect to exhibit significant variations in intensity and shape across different propagation directions, severely impacting imaging consistency. Furthermore, traditional wave number-to-thickness inference methods, which often rely on isotropy, ignore the fiber layup angle, leading to distorted results.

[0043] In order to solve the above technical problems, or to achieve at least one of the above advantages or other advantages, an embodiment of the present invention provides a composite material damage identification method based on ultrasonic guided waves, and innovatively proposes the WAET (Wavenumber-Angle-Effective Thickness, WAET) algorithm. -angle -Actual effective thickness The relationship between the three constructs the WAET three-dimensional surface mapping model At a known incident angle and wave number In this case, the WAET 3D surface mapping model can be The only way to determine the actual effective thickness ( , ), thereby achieving accurate identification and imaging of the location, shape and depth of damage to composite materials structures.

[0044] like Figure 1 As shown in , the composite material damage identification method based on ultrasonic guided waves includes the following steps:

[0045] Collect the initial guided wave signal from the material under test, convert the initial guided wave signal into a frequency domain wave field signal and filter the corresponding single frequency field wave according to the main frequency to obtain a single frequency frequency domain field wave signal;

[0046] Process the single-frequency frequency domain field wave signal, calculate the phase space gradient, and construct the spatial wave number field based on the phase space gradient;

[0047] A WAET three-dimensional surface mapping model is constructed according to the property information of the tested material. The spatial wavenumber field is combined with the WAET three-dimensional surface mapping model to construct an effective thickness map, and the damage information is obtained through the effective thickness map.

[0048] This embodiment preferably uses Lamb waves as the ultrasonic guided wave signal. During propagation, Lamb waves interact with damaged areas of the material being tested, containing a wealth of information without significant dissipation. Therefore, they can carry damage information over long distances, facilitating the detection of large-area specimens. By using a laser to scan space at a specific step size and receive Lamb wave signals, time-space wavefield data can be obtained for the entire scanned area. Frame-by-frame playback of the guided wavefield allows for intuitive visualization of the interaction between the Lamb wave and structural features or damage at different moments. Further analysis of the wavefield signal using damage imaging technology enables quantitative detection of structural damage.

[0049] Of course, SH waves, surface waves, axisymmetric guided waves propagating in tubular structures, etc. may also be used, all of which are within the scope of protection of this application.

[0050] In a specific implementation, the material being tested is a composite material structure. An excitation device is placed on the surface of the composite material structure. By applying an excitation signal at a specific main frequency (e.g., 200 kHz), a guided wave mode is generated that propagates through the structure. Preferably, a piezoelectric ceramic transducer (PZT) is used as the excitation device.

[0051] A scanning laser Doppler vibrometer (SLDV) scans a selected area of ​​the composite structure's surface at spatial sampling points to acquire the initial guided wave signal. The sampling step size, frequency bandwidth, and scanning range are determined by the structural scale and defect resolution requirements to ensure spatial integrity and frequency resolution for subsequent data analysis.

[0052] Preferably, the initial guided wave signal is a spatial sampling point on the surface of the composite material structure being tested. In time Three-dimensional out-of-plane displacement field data under .

[0053] The collected initial waveguide signal is converted into a frequency domain wave field signal and the corresponding single-frequency field wave is filtered according to the main frequency to obtain a single-frequency frequency domain field wave signal, which can separate the target mode and improve the signal-to-noise ratio of subsequent spatial phase extraction.

[0054] In specific implementation, the three-dimensional out-of-plane displacement field data Perform three-dimensional Fourier transform to obtain frequency domain wave field signal , and the wave field signal in the frequency domain Filter out the single frequency component corresponding to the main frequency of the excitation signal , to extract the single-frequency frequency domain field wave signal .

[0055] The single frequency domain field wave signal Expressed as:

[0056]

[0057] in, is the three-dimensional Fourier transform.

[0058] For single frequency domain field wave signal The phase space gradient is processed and calculated, and the spatial wave number field is constructed based on the phase space gradient. The main phase structure of the waveguide signal is extracted by complex space operators, which can effectively suppress local phase disturbances.

[0059] In specific implementation, the Rees transform is used to transform the single-frequency frequency domain field wave signal Process and calculate the Direction and The complex spatial gradient component of the direction 、 , after constructing the analytical field, calculate its angle and obtain the phase field , then the phase field Expressed as:

[0060]

[0061] in, is the inverse tangent operation.

[0062] To eliminate the phase field in Jump to make it have physical continuity, and use path tracking phase unwrapping algorithm. The phase at the reference phase point , then the adjacent phase points of the corresponding path are expanded using the following difference:

[0063]

[0064]

[0065] Then the unwrapped continuous phase field Expressed as:

[0066] ,

[0067] in, Indication Standard Periodic phase expansion operation to ensure full-field phase continuity, represents the continuous phase after unwrapping, represents the unwrapped phase.

[0068] Furthermore, the continuous phase field is calculated by the central difference method The spatial gradient of . Spatial wave number field Through the continuous phase field The first-order gradient modulus is constructed, and the spatial partial derivative is approximated using the central difference value as follows:

[0069]

[0070] Then the spatial wave number field Expressed as:

[0071]

[0072] in, 、 Continuous phase field exist 、 The spatial gradient of the direction, 、 The adjacent sampling points are 、 Spatial spacing in direction.

[0073] On the basis of the above, if Figure 2As shown in the figure, a WAET three-dimensional surface mapping model is constructed based on the property information of the composite material being tested. The essence of the WAET three-dimensional surface mapping model is a nonlinear interpolation three-dimensional surface based on the frequency, material parameters, and mode type. and wave number In the case of , thereby achieving accurate identification and imaging of the location, shape and depth of damage to composite materials structures.

[0074] Specifically, the WAET three-dimensional surface mapping model is constructed based on the thickness, density, stiffness, ply orientation and other attribute information of the tested composite material, which includes the following steps:

[0075] The wave number-angle dispersion curve set at multiple key effective thicknesses in the tested composite material is calculated by semi-analytical finite element method . Key effective thickness The selection is based on the laminated structure of the composite material being tested. The thickness of each single layer in its layup configuration is discrete intervals, and the thickness is accumulated layer by layer from the surface thickness to the overall thickness, which are all key effective thicknesses.

[0076] Based on multiple key effective thicknesses The wave number-angle dispersion curve set at , a WAET three-dimensional surface mapping model of wave number-angle-effective thickness was established through cubic spline interpolation ;

[0077] in, is the propagation direction of the guided wave, is the set of key effective thicknesses, Key effective thickness To the corresponding wave number mapping function, is the actual effective thickness in the waveguide propagation direction and at the spatial sampling point The mapping function from the two corresponding wave numbers.

[0078] It should be noted that the modeling process of the WAET three-dimensional surface mapping model is carried out at a fixed excitation frequency and includes the following steps in sequence:

[0079] First, in the framework of elastodynamics, guided wave propagation in materials is governed by the basic momentum conservation equation:

[0080]

[0081] in, is the material density, is the three-dimensional displacement vector function, is the stress tensor. In order to meet the needs of frequency domain analysis, the simple harmonic wave hypothesis is introduced, that is, it is assumed that the guided wave propagates periodically on the surface of the structure, and its displacement field can be written as:

[0082]

[0083] in, represents the mode function in the thickness direction, 、 is the wave number component in the in-plane direction, is the set excitation angular frequency, is an imaginary unit. Substitute this displacement field into the governing equation and add Using finite element discretization, we can construct a generalized eigenvalue problem about wave number:

[0084]

[0085] in, is the frequency-dependent stiffness matrix, is the mass matrix, is the discrete displacement modal vector, is the total wave number mode.

[0086] In order to express the dependence of wave number on the propagation direction of guided waves, the direction angle parameter is introduced , assuming that the waveguide is in the plate at an angle The in-plane wave number component can be expressed as:

[0087]

[0088] Substituting this angle definition into the eigenvalue problem, we can get Solve the corresponding wave value , and then get the actual effective thickness for The wave number-angle dispersion relationship when :

[0089]

[0090] Among them, the function Characterizes the actual effective thickness for The characteristics of the wave number changing with angle.

[0091] In order to further expand to the thickness dimension, it is necessary to construct a set of “critical effective thicknesses” corresponding to the actual number of layers of the composite material being tested. Layers are laid, each layer has the same thickness and is , then define the critical thickness set for:

[0092]

[0093] in, Indicates the cumulative thickness from the surface to the overall structure layer by layer, .

[0094] At each key effective thickness Repeat the angle scanning process to obtain the fixed frequency Next, the wave number distribution under the key effective thickness-angle joint condition:

[0095]

[0096] in, For the critical effective thickness ,angle The dominant mode wave number obtained by solving at or modal). By looping through all and A dense set of triplet points can be obtained by combining , characterizing the joint response of wave number to angle and thickness.

[0097] On this basis, the cubic spline interpolation method is used to fit and continuousize the discrete point set to construct a smooth and continuous three-dimensional dispersion function surface:

[0098]

[0099] in, Indicates that at a fixed frequency The wave number of the lower dominant mode changes with angle The actual effective thickness This function constitutes the WAET three-dimensional surface mapping model in the present invention.

[0100] Compared with the traditional two-dimensional dispersion model, this model shows that the angle dimension is added , which can truly reflect the influence of the anisotropy of composite materials on the wave number, and significantly improve the directional adaptability and accuracy of effective thickness inversion and damage image recognition.

[0101] Furthermore, the spatial wave number field Combined with WAET 3D surface mapping model Constructing an effective thickness map , and through the effective thickness diagram Get damage information.

[0102] In specific implementation, for each spatial sampling point, according to the known spatial wave number field and direction of transmission , in WAET 3D surface mapping model The actual effective thickness of the corresponding position is obtained by inversion , then the actual effective thickness Expressed as:

[0103]

[0104] in, WAET 3D surface mapping model middle The inverse function of represents the mapping relationship from wave number and propagation direction to effective thickness in the WAET three-dimensional surface model.

[0105] The actual effective thickness of each The effective thickness map is constructed by color processing according to the spatial coordinates of the spatial sampling points , that is, the final damage recognition image is obtained. The actual effective thickness of the local area in the image The abnormal mutation is the potential defect area, which can achieve high-precision positioning and deep identification of local damage in the structure.

[0106] In some preferred embodiments, the present invention also provides simulation verification of the above method, using ABAQUS software to simulate the propagation of guided waves. In the simulation, a 400 mm × 400 mm × 1.2 mm six-layer composite laminate model was established, with each layer being 0.2 mm thick. Its properties are shown in Table 1.

[0107] Table 1

[0108]

[0109] The composite laminate was laid out in a [-45 / 45 / 0]s pattern. The selected sensing area was a 120mm x 120mm square on the laminate surface. The damage was a circular delamination with a diameter of 30mm located at the center of the selected sensing area, with a depth of 0.6mm, between the third and fourth plies of the composite laminate. The damage was achieved by disconnecting the simulation elements at the corresponding locations on the third and fourth plies. This defect represents a phenomenon such as debonding between the composite plies.

[0110] A 200kHz five-peak sine wave modulated by a Hanning window is used as the excitation signal and applied to one of multiple excitation points to create incident waves at different angles relative to the selected sensing area. These excitation points correspond to incident angles of 0°, 45°, -45°, and -90°.

[0111] The SLDV device acquisition end is used to scan the selected sensing area at spatial sampling points one by one to measure its out-of-plane displacement field. The step size is 0.5 mm, the total number of scanning points is 58081, and each point is averaged 20 times. The scanning time for each experiment is about 4 hours.

[0112] Figure 3 Schematic diagram of the wave number field at different incident angles, where the incident angle of a is 0° and the incident angle of b is 45°. Figure 3 It can be seen that the guided wave signal shows significant differences in intensity and shape when facing the same defect and in different propagation directions.

[0113] Then, a WAET three-dimensional surface mapping model is constructed based on the thickness, density, stiffness, ply direction and other attribute information of the composite laminate model, and an effective thickness map is constructed in combination with the spatial wave number field, such as Figure 4 As shown, a is a schematic diagram of the damage identification results of the existing conventional method when the incident direction is 0°; b is a schematic diagram of the damage identification results of the existing conventional method when the incident direction is 45°; c is a schematic diagram of the damage identification results of the present invention when the incident direction is 0°; d is a schematic diagram of the damage identification results of the present invention when the incident direction is 45°.

[0114] In some preferred embodiments, the present invention also provides a composite material damage identification system based on ultrasonic guided waves, which is used to implement the above-mentioned composite material damage identification method based on ultrasonic guided waves. The composite material damage identification system based on ultrasonic guided waves includes an acquisition module and a signal processing and algorithm module.

[0115] In some preferred embodiments, the present invention further provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, implements the above-mentioned composite material damage identification method based on ultrasonic guided waves.

[0116] In some preferred embodiments, the present invention also provides a computer device comprising at least one processor and a memory communicatively connected to the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the processor to perform the above-mentioned composite material damage identification method based on ultrasonic guided waves.

[0117] In summary, the present invention provides a composite material damage identification method, system, medium and equipment based on ultrasonic guided waves. Compared with the existing technology, the WAET algorithm is used to construct a WAET three-dimensional mapping model and a three-dimensional mapping surface, and a three-dimensional coupling mapping relationship between the wave number, the waveguide angle and the actual effective thickness is obtained. The structural characteristics of the composite material composed of a multi-layer laminated structure laid in an anisotropic manner are fully considered, and the propagation characteristics such as wave velocity, wave number, group velocity at different angles are avoided. The significant anisotropy causes the same defect to show significant differences in intensity and shape in different propagation directions, thereby improving imaging consistency.

[0118] Although more terms such as initial waveguide signal are used herein, the possibility of using other terms is not excluded. Using these terms is merely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restriction is contrary to the spirit of the present invention.

[0119] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to simultaneously solve all the technical problems listed in the prior art or background art. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as limiting the claim.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite material damage identification method based on ultrasonic guided waves, characterized by: The following steps are involved: Collect the initial waveguide signal from the material under test, and the initial waveguide signal is the spatial sampling point on the surface of the material under test. In time Three-dimensional out-of-plane displacement field data under ;Convert the initial waveguide signal into a frequency domain wave field signal and filter the corresponding single frequency field wave according to the main frequency to obtain a single frequency frequency domain field wave signal; Process the single-frequency frequency domain field wave signal, calculate the phase space gradient, and construct the spatial wave number field based on the phase space gradient; Construct a WAET three-dimensional surface mapping model based on the property information of the material being tested: Calculate multiple key effective thicknesses of the material being tested using the semi-analytical finite element method The wave number-angle dispersion curve set at ; Based on multiple key effective thicknesses The wave number-angle dispersion curve set at , a WAET three-dimensional surface mapping model of wave number-angle-effective thickness was established through cubic spline interpolation ; in, is the propagation direction of the guided wave, is the set of key effective thicknesses, Key effective thickness To the corresponding wave number mapping function, is the actual effective thickness in the waveguide propagation direction and at the spatial sampling point The mapping function from the two corresponding wave numbers; The spatial wave number field is combined with the WAET three-dimensional surface mapping model to construct an effective thickness map, and damage information is obtained through the effective thickness map: Combined with WAET 3D surface mapping model Reflect the actual effective thickness ; The actual effective thickness of each The effective thickness map is constructed by color processing according to the spatial coordinates of the spatial sampling points ; Through the effective thickness map Acquire damage information; the damage information at least includes damage location, damage outline and damage depth.

2. The composite material damage identification method based on ultrasonic guided waves according to claim 1, characterized in that: The process of converting the initial waveguide signal into a frequency domain wave field signal and filtering the corresponding single frequency field wave according to the main frequency to obtain a single frequency domain field wave signal comprises the following steps: Three-dimensional out-of-plane displacement field data Perform three-dimensional Fourier transform to obtain frequency domain wave field signal ; Wavefield signal in the frequency domain Filter out the single frequency field wave signal corresponding to the main frequency .

3. The composite material damage identification method based on ultrasonic guided waves according to claim 1, characterized in that: The processing of the single-frequency frequency domain field wave signal, calculating the phase space gradient, and constructing the spatial wave number field according to the phase space gradient comprises the following steps: For single frequency domain field wave signal Apply Rees transform to extract 、 The complex spatial gradient component of the direction, and then the phase field is calculated by the angle ; Phase field Implement path-tracing unwrapping to obtain a continuous phase field ; Calculation of continuous phase field by central difference method spatial gradients; According to the continuous phase field Constructing spatial wave number field based on spatial gradient .

4. The composite material damage identification method based on ultrasonic guided waves according to claim 3, characterized in that: The spatial wave number field Through the continuous phase field The first-order gradient modulus is constructed, and the spatial partial derivative is approximated using the central difference value as follows: Then the spatial wave number field Expressed as: in, 、 The continuous phase field is 、 The spatial gradient of the direction, 、 The adjacent sampling points are 、 Spatial spacing in direction. The damage information at least includes a damage location, a damage outline, and a damage depth.

5. A composite material damage identification system based on ultrasonic guided waves, characterized by: Used to implement the composite material damage identification method based on ultrasonic guided waves as described in any one of claims 1 to 4, the composite material damage identification system based on ultrasonic guided waves includes an acquisition module and a signal processing and algorithm module.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer is executed by a processor, the composite material damage identification method based on ultrasonic guided waves according to any one of claims 1 to 4 is implemented.

7. A computer device, characterized in that: The method comprises at least one processor and a memory communicatively connected to the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the processor executes the composite material damage identification method based on ultrasonic guided waves according to any one of claims 1 to 4.

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