Nondestructive testing equipment for internal defects of gear based on ultrasonic guided waves and use method of nondestructive testing equipment

Abstract

The invention provides nondestructive testing equipment for internal defects of a gear based on ultrasonic guided waves and a use method of the nondestructive testing equipment. The nondestructive testing equipment for the internal defects of the gear based on the ultrasonic guided waves comprises a preparation and acquisition module, a model establishment module, a test platform establishment module, an ultrasonic guided wave detection module, a data analysis and processing module and an optimization module, according to the nondestructive testing equipment for the internal defects of the gear based on the ultrasonic guided waves and the use method of the nondestructive testing equipment, the problems that signals are weak and noise interference is large when a traditional method faces complex structures and tiny defects are solved by introducing a time overturning processing technology, the focusing characteristic of the guided waves is utilized for time overturning processing, and the detection accuracy is high. Signal focusing is formed at the defect position, the defect signal strength is remarkably enhanced, noise interference is reduced, tiny defects can be accurately detected, the detection sensitivity is improved, the accuracy of the detection result is improved, and the problems of misjudgment and missed judgment caused by weak signals and noise interference in a traditional method are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, and in particular to a nondestructive testing device for internal defects of gears based on ultrasonic guided waves and a method for using the same. Background Art

[0002] In mechanical transmission systems, gears are key components, and their quality and reliability are crucial to the normal operation of the entire equipment. However, during the manufacturing and use of gears, due to various factors such as materials, processes, and environment, defects such as cracks, pores, and inclusions may occur inside the gears. These defects not only affect the performance and life of the gears, but may also lead to equipment failures and safety accidents. Therefore, internal defect detection of gears is one of the key links to ensure safe and reliable operation of equipment.

[0003] Traditional gear internal defect detection methods, such as X-ray detection and magnetic particle detection, can detect defects inside gears to a certain extent, but they have problems such as low detection efficiency, high cost, and high technical requirements for operators. In addition, these methods may also cause certain damage to the gears, affecting their subsequent use. Therefore, a more efficient, accurate, and non-destructive gear internal defect detection method is needed.

[0004] Ultrasonic guided wave nondestructive testing technology is an emerging testing technology that uses the reflection, transmission and attenuation characteristics of ultrasonic waves when propagating in materials to detect internal defects and cracks in materials. Ultrasonic guided waves have the advantages of long propagation distance, ability to detect defects in any part of the structure, and ability to achieve real-time health monitoring of the structure. They are particularly suitable for nondestructive testing of large and complex structures. In gear testing, ultrasonic guided wave nondestructive testing technology can detect cracks, pores, inclusions and other defects inside the gear by scanning the surface and interior of the gear, providing an important basis for gear quality control and fault diagnosis.

[0005] In ultrasonic guided wave nondestructive testing technology, traditional data analysis methods mainly rely on direct analysis of received guided wave signals, such as identifying defects through waveform comparison, spectrum analysis, etc. However, these methods often face problems such as weak signals, large noise interference, and difficulty in feature extraction when facing complex structures such as gears and tiny defects, which in turn leads to misjudgment and omission of signals generated by tiny defects, reduced sensitivity during detection, and limited accuracy and reliability of detection results.

[0006] Therefore, it is necessary to provide a new nondestructive detection device for internal defects of gears based on ultrasonic guided waves and its use method to solve the above technical problems. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a gear internal defect nondestructive detection device based on ultrasonic guided waves and a method for using the same.

[0008] The nondestructive testing device for internal defects of gears based on ultrasonic guided waves provided by the present invention comprises: a preparation and acquisition module, which is used to select the type of gear to be tested and record the basic data of the selected gear in detail;

[0009] Model building module, used to build a three-dimensional numerical model based on the basic data of the selected gear and select the most suitable waveguide type for finite element simulation analysis;

[0010] The test platform building module is used to build a gear defect nondestructive testing test platform and perform ultrasonic guided wave testing on the gears based on the simulation results using testing equipment;

[0011] Ultrasonic guided wave detection module, used to transmit pre-selected guided waves into the interior of the gear, use a receiver to receive the guided wave signal reflected from the interior of the gear, and record the received signal data in detail, including waveform, amplitude and phase;

[0012] The data analysis and processing module uses numerical analysis and signal processing technology to analyze the received signal and perform time reversal processing on the received signal. The time reversal processing includes reversing the received waveguide signal in time to make it conjugate with the original transmission signal, re-transmitting the time-reversed signal into the gear, and focusing the signal at the defect by using the focusing characteristics of the waveguide. The defect position and type inside the gear are identified by analyzing the characteristics of the focused signal.

[0013] The optimization module adjusts and optimizes the parameters of the detection equipment according to the results of experimental verification.

[0014] Preferably, the specific operation steps of the data analysis and processing module are:

[0015] Step 1: Signal loading and preprocessing: Loading waveform, amplitude and phase information from the signal data received and recorded by the ultrasonic guided wave detection module, and preprocessing the loaded signal;

[0016] Step 2: Time reversal processing: Based on the preprocessed signal, the signal is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear. When the signal is re-transmitted, it interacts with defects in the propagation medium, including scatterers, thereby forming a focus at the scatterers.

[0017] Step 3: Extracting the features of the focusing signal: After the signal is retransmitted and focused, the receiver is used to receive the focusing signal again, and the received focusing signal is analyzed in detail to extract its feature information, including the amplitude change and phase shift of the signal;

[0018] Step 4: Defect identification and location: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear, and the specific location of the defect inside the gear is determined by using the focusing position of the waveguide and the intensity of the characteristic information;

[0019] Step 5: Result output and report generation: Organize the results of defect identification and location, generate a detailed test report, and output the test report to a display device or storage device for user viewing or subsequent analysis;

[0020] Step 6. Data feedback and optimization: Compare the analysis results with the results of experimental verification, evaluate the accuracy and reliability of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results.

[0021] Preferably, in the preparation and acquisition module, the basic data includes the material, size and expected defect type of the selected gear, wherein the expected defect type includes cracks, wear and corrosion of the gear.

[0022] Preferably, in the preparation and acquisition module, the gear types include passenger car gears and industrial robot joint RV reducers.

[0023] Preferably, the specific operation steps of the model building module are:

[0024] S1. Establish a three-dimensional numerical model: First, use COMSOL finite element simulation software to establish a three-dimensional numerical model based on the basic data of the selected gear in the preparation and acquisition module.

[0025] S2. Select the guided wave type: According to the propagation characteristics of ultrasonic guided waves and the characteristics of gears, select longitudinal mode or torsional mode for simulation.

[0026] S3. Set excitation and reception: Set the excitation source and receiving point of the ultrasonic guided wave in the numerical model to simulate the probe position and direction in actual detection.

[0027] Preferably, the detection equipment includes an ultrasonic guided wave transducer, an arbitrary waveform generator, a digital oscilloscope and a power amplifier.

[0028] Preferably, in the model building module, the waveguide types also include Lamb waveguide and SH waveguide.

[0029] Preferably, the gear defect nondestructive testing platform includes an operating table, a mounting frame is fixed to one side of the operating table, a display screen is fixed to the surface of the operating table, a clamping mechanism is fixed to the top of the mounting frame, a placement groove for gear installation is provided at the center of the clamping mechanism, a detection box is fixed to one side of the clamping mechanism, and the ultrasonic guided wave transducer and the power amplifier are both fixed to one side of the clamping mechanism, the ultrasonic guided wave transducer is located between the detection box and the power amplifier, and the ultrasonic transducer is located directly above the placement groove.

[0030] The method of using the nondestructive testing equipment for internal defects of gears based on ultrasonic guided waves includes the following stages:

[0031] Step 1, preparation and collection stage: First, record the material, size and expected defect type of the passenger car gear or industrial robot joint RV reducer to be inspected;

[0032] Step 2, model building stage: After the recording is completed, use COMSOL finite element simulation software to build a three-dimensional numerical model of the gear according to the recorded basic data. According to the propagation characteristics of ultrasonic guided waves and the characteristics of the gear, select the longitudinal mode or torsional mode for simulation, or select Lamb guided wave and SH guided wave types. After the selection is completed, set the excitation source and receiving point of the ultrasonic guided wave in the numerical model to simulate the probe position and direction in the actual detection;

[0033] Step 3, test platform construction stage: According to the simulation results, use the operating table, mounting frame, display screen, clamping mechanism, detection box, ultrasonic guided wave transducer, arbitrary waveform generator, digital oscilloscope and power amplifier to build a gear defect nondestructive detection test platform, and install the gear in the placement slot of the clamping mechanism;

[0034] Step 4, ultrasonic guided wave detection stage: After the gear is installed, use the ultrasonic guided wave transducer to transmit the pre-selected guided wave into the gear, use the digital oscilloscope to receive the guided wave signal reflected from the gear, and record the signal data in detail, including the waveform, amplitude and phase;

[0035] Step 5, signal loading and preprocessing stage: after recording is completed, the waveform, amplitude and phase information are loaded, and the loaded signal is denoised and filtered;

[0036] Step 6, time reversal processing and focusing stage: according to the signal after denoising and filtering, the signal is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear to focus the signal at the defect. After focusing is completed, the digital oscilloscope is used again to receive the focused signal;

[0037] Step 7, focusing signal feature extraction stage: Analyze the received focusing signal in detail and extract feature information, including extracting the amplitude change and phase shift of the signal;

[0038] Step 8, defect identification and positioning stage: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear, and the specific location of the defect inside the gear is determined by using the focusing position of the waveguide and the intensity of the characteristic information;

[0039] Step 9, Result output and report generation stage: Organize the results of defect identification and positioning, generate a detailed test report, and output the test report to the display screen for users to view or use for subsequent analysis;

[0040] Step 10, data feedback and optimization stage: Compare the analysis results with the results of experimental verification, evaluate the accuracy of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results. At the same time, adjust and optimize the parameters of the detection equipment based on the experimental feedback.

[0041] Preferably, in the step Step 10, the parameters of the detection equipment are adjusted and optimized, including adjusting and optimizing the frequency of the ultrasonic guided wave transducer and the gain of the power amplifier.

[0042] Compared with the related art, the gear internal defect nondestructive testing device based on ultrasonic guided waves and the use method thereof provided by the present invention have the following beneficial effects:

[0043] 1. By introducing the time-reversal processing technology, the present invention effectively solves the problem of weak signal and strong noise interference in traditional methods when facing complex structures and tiny defects. Time-reversal processing uses the focusing characteristics of waveguides to form signal focus at the defect, thereby significantly enhancing the defect signal strength and reducing noise interference, so that tiny defects can also be accurately detected. This not only improves the sensitivity of detection, but also greatly improves the accuracy of the detection results, avoiding the problems of misjudgment and missed judgment caused by weak signals and noise interference in traditional methods;

[0044] 2. Based on the traditional waveform comparison and spectrum analysis methods, the present invention increases the accuracy of feature extraction. Through the signal after time flip processing, it is easier to extract key characteristic parameters such as wave velocity change, amplitude attenuation and frequency offset, making the type, location and size of the defect more accurate and reliable;

[0045] 3. The equipment and method of the present invention are not only suitable for internal defect detection of complex structures such as gears, but can also be widely used in non-destructive testing of other metal components, composite materials, pipelines and other industrial fields, broadening the application scope of ultrasonic guided wave non-destructive testing technology, and has the advantages of good use effect and high applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the process of the nondestructive testing device for internal defects of gears based on ultrasonic guided waves provided by the present invention;

[0047] Figure 2 It is a schematic diagram of the overall structure of the gear defect nondestructive testing test platform;

[0048] Figure 3 This is a schematic diagram of the structure of the gear defect nondestructive testing test platform.

[0049] Numbers in the figure: 1. operating table; 2. mounting frame; 3. display screen; 4. clamping mechanism; 41. placement slot; 5. detection box; 6. ultrasonic guided wave transducer; 7. power amplifier. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0051] Please refer to Figures 1 to 3 ,in, Figure 1 A schematic diagram of the process of the nondestructive testing device for internal defects of gears based on ultrasonic guided waves provided by the present invention; Figure 2 It is a schematic diagram of the overall structure of the gear defect nondestructive testing test platform; Figure 3 This is a schematic diagram of the structure of the gear defect nondestructive testing test platform.

[0052] Embodiment 1

[0053] In the specific implementation process, Figures 1 to 3 As shown, it includes a preparation and acquisition module, which is used to select the type of gear to be detected and record the basic data of the selected gear in detail, wherein the basic data includes the material, size and expected defect type of the selected gear; the expected defect type includes cracks, wear and corrosion of the gear;

[0054] Model building module, used to build a three-dimensional numerical model based on the basic data of the selected gear and select the most suitable waveguide type for finite element simulation analysis;

[0055] A test platform building module, used to build a gear defect nondestructive testing platform and perform ultrasonic guided wave testing on the gears using a testing device according to the simulation results, wherein the testing device includes an ultrasonic guided wave transducer (6), an arbitrary waveform generator, a digital oscilloscope, and a power amplifier (7);

[0056] The gear defect nondestructive testing platform comprises an operating table (1), a mounting frame (2) is fixed on one side of the operating table (1), a display screen (3) is fixed on the surface of the operating table (1), a clamping mechanism (4) is fixed on the top of the mounting frame (2), a placement groove (41) for gear installation is provided at the center of the clamping mechanism (4), a detection box (5) is fixed on one side of the clamping mechanism (4), and the ultrasonic guided wave transducer (6) and the power amplifier (7) are both fixed on one side of the clamping mechanism (4), the ultrasonic guided wave transducer (6) is located between the detection box (5) and the power amplifier (7), and the ultrasonic transducer (6) is located directly above the placement groove (41).

[0057] It should be noted that the digital oscilloscope and the arbitrary waveform generator are placed inside the detection box 5 to record the received signal data in detail, including waveform, amplitude and phase;

[0058] Ultrasonic guided wave detection module, used to transmit pre-selected guided waves into the interior of the gear, use a receiver to receive the guided wave signal reflected from the interior of the gear, and record the received signal data in detail, including waveform, amplitude and phase;

[0059] The data analysis and processing module uses numerical analysis and signal processing technology to analyze the received signal and perform time reversal processing on the received signal. The time reversal processing includes reversing the received waveguide signal in time to make it conjugate with the original transmission signal, re-transmitting the time-reversed signal into the gear, and focusing the signal at the defect by using the focusing characteristics of the waveguide. The defect position and type inside the gear are identified by analyzing the characteristics of the focused signal.

[0060] The optimization module adjusts and optimizes the parameters of the testing equipment according to the results of experimental verification;

[0061] It should be noted that in the preparation and acquisition module, the gear types include passenger car gears and industrial robot joint RV reducers;

[0062] It should be noted that the most suitable waveguide type is selected, including selecting longitudinal mode or torsional mode for simulation, or selecting Lamb waveguide and SH waveguide types;

[0063] Among them, the following analyses are conducted on longitudinal modes, torsional modes, Lamb guided waves and SH guided waves:

[0064] Longitudinal mode: The main propagation direction is consistent with the wave propagation direction, which is suitable for detecting defects in the material along the wave propagation direction;

[0065] Torsional mode: The propagation direction of the wave is perpendicular to the vibration direction of the particle, which is suitable for detecting torsional stress or defects in the material;

[0066] Lamb waveguide detection of gear defects: Lamb waveguide is a two-dimensional elastic wave propagating in a flat plate or a similar flat plate structure. Lamb wave exists in the form of a resonant mode. In gear detection, Lamb waveguide is excited by arranging an ultrasonic transducer (6) on or near the surface of the gear. After receiving the electrical signal, the transducer generates mechanical vibration, thereby exciting the waveguide inside the gear. When the Lamb waveguide propagates inside the gear, it interacts with the geometric shape, material properties and existing defects of the gear. When the waveguide encounters a defect, reflection, scattering and other phenomena will occur, causing the propagation characteristics of the waveguide to change. At this time, a receiving transducer, such as a digital oscilloscope, is arranged on the other side of the gear to receive the waveguide signal reflected from the inside of the gear. The received signal includes waveform, amplitude, phase and other information to reflect the defect inside the gear. By filtering and Fourier transforming the received signal, characteristic information related to the defect is extracted, including the location, size and type of the defect. Based on the extracted characteristic information, imaging processing is further performed to display the location and shape of the defect in the form of an image, that is, displayed on the display screen (3) for user viewing or subsequent analysis.

[0067] SH guided wave detection of gear defects: SH guided wave is a type of horizontal shear wave, and its vibration direction is perpendicular to the wave propagation direction and the material surface. SH guided wave is highly sensitive to defects perpendicular to the wave propagation direction, such as cracks. In gear detection, an ultrasonic transducer (6) is used to excite the SH guided wave. Similar to Lamb guided wave detection, SH guided wave detection also requires the arrangement of a receiving transducer to receive the reflected guided wave signal. The received signal also contains waveform, amplitude, phase, etc. The received signal is filtered and Fourier transformed to extract characteristic information related to the defect. Based on the extracted characteristic information, the defects inside the gear can be evaluated, including determining the location, size, type of the defects, and defects that may affect the performance and life of the gear;

[0068] It should be noted that the specific operation steps of the model building module are:

[0069] S1. Establish a three-dimensional numerical model: First, use COMSOL finite element simulation software, according to the basic data of the selected gear provided in the preparation and acquisition module, including material, size, number of teeth, etc., input these basic data into COMSOL, and use the modeling function of COMSOL to build a three-dimensional numerical model of the gear according to the input data;

[0070] S2. Select the guided wave type: Analyze the structural characteristics of the gear and possible defect types, such as cracks, inclusions, etc. According to the propagation characteristics of ultrasonic guided waves and the characteristics of the gear, select the longitudinal mode or torsional mode for simulation;

[0071] For example, to detect crack defects inside gears, longitudinal mode guided waves that are sensitive to cracks would be selected.

[0072] S3. Setting excitation and reception: setting the excitation source of ultrasonic guided waves in the numerical model to simulate the ultrasonic guided waves emitted by the probe in actual detection;

[0073] Set receiving points in the numerical model to simulate the receiving position and direction of the probe in actual detection;

[0074] Through numerical simulation, the propagation process of ultrasonic guided waves inside the gear and its interaction with defects are simulated, and the guided wave signal at the receiving point is obtained.

[0075] It should be noted that the parameters such as the position, direction and frequency of the excitation source should be set according to the selected waveguide type and gear characteristics; the number and position of the receiving points should be reasonably arranged according to the detection requirements and gear structure.

[0076] It should be noted that the three-dimensional numerical model established using finite element simulation software such as COMSOL can accurately simulate the geometric shape and material properties of the gear, as well as the propagation process of ultrasonic guided waves inside the gear, which helps to improve the accuracy of subsequent simulation analysis and actual detection;

[0077] It should be noted that according to the characteristics of the gear and the propagation characteristics of the ultrasonic guided wave, the most suitable guided wave type is selected for simulation, which can more effectively detect the defects inside the gear and help improve the sensitivity and reliability of the detection;

[0078] It should be noted that by setting reasonable excitation sources and receiving points, the position and direction of the probe in actual testing can be simulated, thereby obtaining a more realistic waveguide signal, which is helpful for subsequent signal analysis and defect identification;

[0079] It should be noted that by comparing the simulation results with the actual test results, the performance and parameters of the test equipment can be further verified and optimized.

[0080] refer to Figure 1As shown, the specific operation steps of the data analysis and processing module are:

[0081] Step 1: Signal loading and preprocessing: Loading waveform, amplitude and phase information from the signal data received and recorded by the ultrasonic guided wave detection module, and then preprocessing the loaded signal;

[0082] Step 2: Time reversal processing: Based on the preprocessed signal, the signal is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear. When the signal is re-transmitted, it interacts with defects in the propagation medium, including scatterers, thereby forming a focus at the scatterer.

[0083] It should be noted that in the time-flip processing step, the signal strength at the defect is enhanced, thereby improving the sensitivity of defect detection;

[0084] Step 3: Extracting the features of the focusing signal: After the signal is retransmitted and focused, the receiver is used to receive the focusing signal again, and the received focusing signal is analyzed in detail to extract its feature information, including the amplitude change and phase shift of the signal;

[0085] Step 4: Defect identification and location: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear. At the same time, the focus position of the waveguide and the intensity of the characteristic information are used to determine the specific location of the defect inside the gear.

[0086] Step 5: Result output and report generation: Organize the results of defect identification and location and generate a test report, which contains detailed information such as defect type, location, size, etc. The test report is output to a display device or storage device for user viewing or subsequent analysis;

[0087] Step 6. Data feedback and optimization: Compare the analysis results with the results of experimental verification, evaluate the accuracy and reliability of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results.

[0088] It should be noted that the detection device includes an ultrasonic guided wave transducer (6), an arbitrary waveform generator, a digital oscilloscope and a power amplifier (7);

[0089] The method of using the nondestructive testing equipment for internal defects of gears based on ultrasonic guided waves includes the following stages:

[0090] Step 1, preparation and collection stage: First, record the material, size and expected defect type of the passenger car gear or industrial robot joint RV reducer to be inspected;

[0091] Among them, the material of the gear, such as cast steel, alloy steel, etc.; the size, such as diameter, thickness, number of teeth, etc.; the type of defects expected to be detected, such as cracks, inclusions, pores, etc.;

[0092] Step 2, model building stage: After the recording is completed, use COMSOL finite element simulation software to build a three-dimensional numerical model of the gear according to the recorded basic data. According to the propagation characteristics of ultrasonic guided waves and the characteristics of the gear, select the longitudinal mode or torsional mode for simulation, or select Lamb guided wave and SH guided wave types. After the selection is completed, set the excitation source and receiving point of the ultrasonic guided wave in the numerical model to simulate the probe position and direction in the actual detection;

[0093] It should be noted that through simulation, the propagation path and reflection characteristics of ultrasonic guided waves in gears can be predicted, providing theoretical guidance for actual detection and reducing trial and error costs;

[0094] Step 3, test platform construction stage: according to the simulation results, use the operating table (1), the mounting frame (2), the display screen (3), the clamping mechanism (4), the detection box (5), the ultrasonic guided wave transducer (6), the arbitrary waveform generator (7), the digital oscilloscope and the power amplifier (7) to build a gear defect nondestructive detection test platform, and install the gear in the placement slot (41) of the clamping mechanism to ensure that the gear is stable and easy to detect;

[0095] The clamping mechanism (4) is used to fix and limit the outer side of the gear. When in use, the mounting plates at both ends of the clamping mechanism 4 are moved toward the middle to fix the outer side of the clamping mechanism 4.

[0096] Step 4, ultrasonic guided wave detection stage: after the gear is installed, use the ultrasonic guided wave transducer (6) to transmit the pre-selected guided wave into the gear, use the digital oscilloscope to receive the guided wave signal reflected from the gear, and record the signal data in detail, including the waveform, amplitude and phase;

[0097] It should be noted that by transmitting and receiving ultrasonic guided waves, the reflection signal of the internal defects of the gear can be obtained, which is beneficial to subsequent operations;

[0098] Step 5, signal loading and preprocessing stage: After recording is completed, the waveform, amplitude and phase information are loaded, and the loaded signal is denoised and filtered to improve the signal quality and reduce noise interference;

[0099] It should be noted that signal preprocessing improves the accuracy and reliability of defect detection;

[0100] Step 6, time reversal processing and focusing stage: the signal after denoising and filtering is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear to focus the signal at the defect. After focusing is completed, the digital oscilloscope is used again to receive the focused signal;

[0101] Step 7, focusing signal feature extraction stage: Analyze the received focusing signal in detail and extract feature information, including extracting the amplitude change and phase shift of the signal;

[0102] Step 8, defect identification and positioning stage: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear, and the specific location of the defect inside the gear is determined by using the focusing position of the waveguide and the intensity of the characteristic information;

[0103] It should be noted that the use of defect identification and location can accurately determine the type and location of defects inside the gear, which is convenient for subsequent repair and treatment;

[0104] Step 9, Result output and report generation stage: Organize the results of defect identification and positioning, generate a detailed test report, and output the test report to the display screen for users to view or use for subsequent analysis;

[0105] It should be noted that the use of detailed test reports provides users with intuitive test results, which facilitates subsequent analysis and decision-making;

[0106] Step 10, data feedback and optimization stage: Compare the analysis results with the results of experimental verification, evaluate the accuracy of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results. At the same time, adjust and optimize the parameters of the detection equipment based on the experimental feedback.

[0107] It should be noted that, in step 10, the parameters of the detection device are adjusted and optimized, including adjusting and optimizing the frequency of the ultrasonic guided wave transducer (6) and the gain of the power amplifier (7).

[0108] Embodiment 2

[0109] refer to Figures 1 to 3 As shown, unlike the first embodiment, the second embodiment uses specific data for analysis:

[0110] For example:

[0111] Step 1: Preparation and collection stage

[0112] Gear to be tested: Helical gear for passenger cars, made of 20CrMnTi, module 4, number of teeth 30, thickness 30mm;

[0113] Expected detection defects: crack defects;

[0114] Record the data into the table as shown below

[0115] project describe Gear Material 20CrMnTi Modulus 4 Number of teeth 30 thickness 30mm Expected detection defects crack

[0116] Step 2: Model building stage

[0117] Simulation software: COMSOL Multiphysics 5.6

[0118] Guided wave type: Select longitudinal mode L(0,1)

[0119] Excitation source and receiving point: The excitation source is located on one side of the gear, and the receiving points are evenly distributed on the other side of the gear. A total of 10 receiving points are set

[0120] Simulation settings:

[0121] Mesh division: tetrahedral mesh is used with a mesh size of 2 mm;

[0122] In terms of boundary conditions: the outer edge of the gear is set as a free boundary, and the inner hole is set as a fixed boundary;

[0123] As for the excitation signal: a sine wave is used with a frequency of 50kHz and a duration of 0.1ms.

[0124] Step 3: Test platform construction stage

[0125] Equipment list: operating table, mounting frame, display screen, clamping mechanism, detection box, ultrasonic guided wave transducer, arbitrary waveform generator, model: AFG3252, digital oscilloscope, model: MSO5204A, power amplifier shared with arbitrary waveform generator.

[0126] The dimensions of the clamping mechanism placement slot are: length x width x height = 150mm x 100mm x 50mm.

[0127] Step 3: Test platform construction stage

[0128] First, install the gear in the placement slot 41 of the clamping mechanism 4 to ensure that the gear is stable and easy to detect;

[0129] Secondly, connect the ultrasonic guided wave transducer 6, arbitrary waveform generator, digital oscilloscope and power amplifier 7 according to the standard to ensure correct signal transmission.

[0130] Finally, turn on the power of the operating table 1, start the simulation software, and prepare for ultrasonic guided wave testing.

[0131] Step 4: Ultrasonic guided wave testing

[0132] An ultrasonic guided wave transducer 6 is used to transmit a guided wave of longitudinal mode L(0,1) to the inside of the gear. A digital oscilloscope receives the guided wave signal reflected from the inside of the gear and records the waveform, amplitude and phase as follows:

[0133] Receiving point number Waveform Amplitude(V) Phase(°) 1 Sine Wave 0.12 30 2 Slight distortion 0.10 28 ...... ...... ...... ...... 10 Obvious distortion 0.25 45

[0134] Step 5: Signal loading and preprocessing stage

[0135] The signal data recorded by the digital oscilloscope was loaded into the data analysis software, and the noise was removed by bandpass filtering such as 45-55kHz, followed by wavelet denoising;

[0136] Preprocessing results: Amplitude change after filtering: Amplitude fluctuation is reduced and the signal is clearer;

[0137] Phase change after denoising: The phase deviation is reduced and the signal is more stable.

[0138] Step 6: Time flip processing and focusing stage

[0139] Perform time flip: reverse the preprocessed signal in time to form a conjugate signal.

[0140] Retransmit: The time-reversed signal is retransmitted into the gear so that the signal is focused at the defect.

[0141] Receiving the focus signal: Use the digital oscilloscope to receive the focus signal again.

[0142] The data obtained by the above time flip, retransmission and focused signal reception are recorded

[0143] Focus point number Amplitude change (V) Phase shift (°) 1(defective part) 0.45 60 2(non-defective) 0.15 35

[0144] Step 7: Focus signal feature extraction stage

[0145] Extracting amplitude change and phase shift as feature information from the focusing signal

[0146] Feature Type Defect value Non-defective value Amplitude change 0.45 0.15 Phase offset 60 35

[0147] Step 8: Defect identification and location stage

[0148] Defect identification: Compare the extracted feature information with the preset defect feature library and identify it as a crack defect;

[0149] Defect location: Based on the focus position of the guided wave and the intensity of the characteristic information, it is determined that the defect is located inside the gear near the tooth root.

[0150] Record Report

[0151] Defect type: crack;

[0152] Defect location: Inside the gear, near the tooth root;

[0153] Defect intensity: Medium;

[0154] Step 9: Result output and report generation stage

[0155] At this time, the results of defect identification and positioning are organized into a detailed test report, including information such as defect type, location, intensity, etc. The test report is output to the display screen for user viewing or subsequent analysis.

[0156] Step 10: Data feedback and optimization stage

[0157] Optimize record table

[0158]

[0159] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0160] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Nondestructive testing equipment for internal defects of gears based on ultrasonic guided waves, characterized in that: It includes a preparation and acquisition module, which is used to select the type of gear to be tested and record the basic data of the selected gear in detail; Model building module, used to build a three-dimensional numerical model based on the basic data of the selected gear and select the most suitable waveguide type for finite element simulation analysis; The test platform building module is used to build a gear defect nondestructive testing test platform and perform ultrasonic guided wave testing on the gears based on the simulation results using testing equipment; Ultrasonic guided wave detection module, used to transmit pre-selected guided waves into the interior of the gear, use a receiver to receive the guided wave signal reflected from the interior of the gear, and record the received signal data in detail, including waveform, amplitude and phase; The data analysis and processing module uses numerical analysis and signal processing technology to analyze the received signal and perform time reversal processing on the received signal. The time reversal processing includes reversing the received waveguide signal in time to make it conjugate with the original transmission signal, re-transmitting the time-reversed signal into the gear, and focusing the signal at the defect by using the focusing characteristics of the waveguide. The defect position and type inside the gear are identified by analyzing the characteristics of the focused signal. The optimization module adjusts and optimizes the parameters of the detection equipment according to the results of experimental verification.

2. The nondestructive testing equipment for gear internal defects based on ultrasonic guided waves according to claim 1 is characterized in that: The specific operation steps of the data analysis and processing module are: Step 1: Signal loading and preprocessing: Loading waveform, amplitude and phase information from the signal data received and recorded by the ultrasonic guided wave detection module, and preprocessing the loaded signal; Step 2: Time reversal processing: According to the pre-processed signal, the signal is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear. When the signal is re-transmitted, it interacts with defects in the propagation medium, including scatterers, so as to form a focus at the scatterers. Step 3: Extracting the features of the focusing signal: After the signal is retransmitted and focused, the receiver is used to receive the focusing signal again, and the received focusing signal is analyzed in detail to extract its feature information, including the amplitude change and phase shift of the signal; Step 4: Defect identification and location: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear, and the specific location of the defect inside the gear is determined by using the focusing position of the waveguide and the intensity of the characteristic information; Step 5: Result output and report generation: Organize the results of defect identification and location, generate a detailed test report, and output the test report to a display device or storage device for user viewing or subsequent analysis; Step 6. Data feedback and optimization: Compare the analysis results with the results of experimental verification, evaluate the accuracy and reliability of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results.

3. The nondestructive testing equipment for gear internal defects based on ultrasonic guided waves according to claim 2 is characterized in that: In the preparation and acquisition module, the basic data includes the material, size and expected defect type of the selected gear, wherein the expected defect type includes cracks, wear and corrosion of the gear.

4. The nondestructive testing equipment for gear internal defects based on ultrasonic guided waves according to claim 3 is characterized in that: In the preparation and acquisition module, the gear types include passenger car gears and industrial robot joint RV reducers.

5. The nondestructive testing equipment for gear internal defects based on ultrasonic guided waves according to claim 4 is characterized in that: The specific operation steps of the model building module are: S1. Establishing a three-dimensional numerical model: First, using COMSOL finite element simulation software, a three-dimensional numerical model is established according to the basic data of the selected gear in the preparation and acquisition module; S2. Select the guided wave type: According to the propagation characteristics of ultrasonic guided waves and the characteristics of gears, select the longitudinal mode or torsional mode for simulation; S3. Set excitation and reception: Set the excitation source and receiving point of the ultrasonic guided wave in the numerical model to simulate the probe position and direction in actual detection.

6. The nondestructive testing equipment for internal defects of gears based on ultrasonic guided waves according to claim 5 is characterized in that: The detection device comprises an ultrasonic guided wave transducer (6), an arbitrary waveform generator, a digital oscilloscope and a power amplifier (7).

7. The nondestructive testing equipment for gear internal defects based on ultrasonic guided waves according to claim 6 is characterized in that: In the model building module, the waveguide types also include Lamb waveguide and SH waveguide.

8. The nondestructive testing equipment for internal defects of gears based on ultrasonic guided waves according to claim 7 is characterized in that: The gear defect nondestructive testing platform comprises an operating table (1), a mounting frame (2) is fixed to one side of the operating table (1), a display screen (3) is fixed to the surface of the operating table (1), a clamping mechanism (4) is fixed to the top of the mounting frame (2), a placement groove (41) for gear installation is provided at the center of the clamping mechanism (4), a detection box (5) is fixed to one side of the clamping mechanism (4), and the ultrasonic guided wave transducer (6) and the power amplifier (7) are both fixed to one side of the clamping mechanism (4), the ultrasonic guided wave transducer (6) is located between the detection box (5) and the power amplifier (7), and the ultrasonic transducer (6) is located directly above the placement groove (41).

9. A method for using the nondestructive testing device for internal defects of gears based on ultrasonic guided waves according to claims 1 to 8, characterized in that: The following stages are included: Step 1, preparation and collection stage: First, record the material, size and expected defect type of the passenger car gear or industrial robot joint RV reducer to be inspected; Step 2, model building stage: After the recording is completed, use COMSOL finite element simulation software to build a three-dimensional numerical model of the gear according to the recorded basic data. According to the propagation characteristics of ultrasonic guided waves and the characteristics of the gear, select the longitudinal mode or torsional mode for simulation, or select Lamb guided wave and SH guided wave types. After the selection is completed, set the excitation source and receiving point of the ultrasonic guided wave in the numerical model to simulate the probe position and direction in the actual detection; Step 3, test platform construction stage: according to the simulation results, a gear defect nondestructive testing platform is constructed using an operating table (1), a mounting frame (2), a display screen (3), a clamping mechanism (4), a detection box (5), an ultrasonic guided wave transducer (6), an arbitrary waveform generator (7), a digital oscilloscope and a power amplifier (7), and the gear is mounted in the placement slot (41) of the clamping mechanism; Step 4, ultrasonic guided wave detection stage: after the gear is installed, use the ultrasonic guided wave transducer (6) to transmit the pre-selected guided wave into the gear, use the digital oscilloscope to receive the guided wave signal reflected from the gear, and record the signal data in detail, including the waveform, amplitude and phase; Step 5, signal loading and preprocessing stage: after recording is completed, the waveform, amplitude and phase information are loaded, and the loaded signal is denoised and filtered; Step 6, time reversal processing and focusing stage: according to the signal after denoising and filtering, the signal is reversed in time to form a conjugate with the original transmitted signal, and the time-reversed signal is re-transmitted into the gear to focus the signal at the defect. After focusing is completed, the digital oscilloscope is used again to receive the focused signal; Step 7, focusing signal feature extraction stage: Analyze the received focusing signal in detail and extract feature information, including extracting the amplitude change and phase shift of the signal; Step 8, defect identification and positioning stage: According to the characteristic information of the focused signal, it is compared with the preset defect feature library to identify the defect type inside the gear, and the specific location of the defect inside the gear is determined by using the focusing position of the waveguide and the intensity of the characteristic information; Step 9, Result output and report generation stage: Organize the results of defect identification and positioning, generate a detailed test report, and output the test report to the display screen for users to view or use for subsequent analysis; Step 10, data feedback and optimization stage: Compare the analysis results with the results of experimental verification, evaluate the accuracy of the data analysis and processing module, and adjust and optimize the algorithms and parameters in the data analysis and processing module based on the comparison results. At the same time, adjust and optimize the parameters of the detection equipment based on the experimental feedback.

10. The method for using the gear internal defect nondestructive testing device based on ultrasonic guided waves according to claim 9 is characterized in that: In the step Step 10, the parameters of the detection device are adjusted and optimized, including adjusting and optimizing the frequency of the ultrasonic guided wave transducer (6) and the gain of the power amplifier (7).

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