Residual stress detection method of electroceramic material, electronic equipment and storage medium

Abstract

The invention belongs to the technical field of residual stress detection, and particularly relates to a residual stress detection method of an electroceramic material, electronic equipment and a storage medium, the method comprises the following steps: obtaining zero-stress samples of a to-be-detected electroceramic material component, the zero-stress samples comprising a zero-stress tensile sample and a zero-stress compression sample; in a first preset temperature range, zero stress acoustic time calibration is carried out on the zero stress sample, and a zero stress acoustic time value is determined; carrying out stress coefficient calibration on the zero-stress sample, and determining an acoustic elastic coefficient; within a second preset temperature range, performing ultrasonic detection on the to-be-detected electro-ceramic material component to obtain a target sound time value; and determining the residual stress value of the to-be-tested electro-ceramic material component based on the zero stress acoustic time value, the acoustic elasticity coefficient and the target acoustic time value. According to the technical scheme provided by the invention, the residual stress detection of the electroceramic material is realized, the quality monitoring in the network access and operation inspection process is enhanced, and the safe and stable operation of a power grid is ensured.

Description

Technical Field

[0001] This application belongs to the field of residual stress detection technology, and in particular relates to a method, electronic device and storage medium for detecting residual stress in electrical porcelain materials. Background Technology

[0002] Porcelain insulators are important components in power plant and substation equipment, and are essential for the mechanical connections and electrical insulation of transmission lines. Porcelain bushings are mainly used for insulating supports of transmission and transformation equipment leads or as insulating containers. Porcelain insulators, porcelain bushings, and other porcelain materials are required to have good mechanical and electrical properties.

[0003] Currently, the testing and inspection items for porcelain insulators entering the power grid mainly include routine tests (appearance, dimensions, form and position deviations, porosity, temperature cycling, etc.), electrical tests (impulse withstand voltage, power frequency voltage, radio interference, visible corona voltage, pollution, breakdown voltage, etc.), and mechanical tests (bending, tensile, torsional failure, compression, electromechanical failure, etc.). There is no suitable testing method for assessing and measuring the internal residual stress of porcelain insulators and porcelain bushings. However, the internal residual stress of porcelain materials is crucial to their service performance, especially their mechanical strength, fatigue life, and equipment stability. Detecting the internal residual stress of porcelain materials can assess their safety under service conditions, thereby strengthening quality control of porcelain materials during grid connection and operation and maintenance, and effectively ensuring the safe and stable operation of the power grid.

[0004] Therefore, how to detect residual stress in electrical porcelain materials to strengthen quality monitoring during grid connection and operation and maintenance, and ensure the safe and stable operation of the power grid, has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method, electronic device, and storage medium for detecting residual stress in electrical porcelain materials, aiming to realize the detection of residual stress in electrical porcelain materials, so as to strengthen quality monitoring during grid connection and operation and maintenance, and ensure the safe and stable operation of the power grid.

[0006] In a first aspect, embodiments of this application provide a method for detecting residual stress in electrical porcelain materials, the method comprising:

[0007] Obtain zero-stress specimens of the electrical porcelain material components to be tested, including zero-stress tensile specimens and zero-stress compression specimens.

[0008] Within a first preset temperature range, the zero-stress sample is subjected to zero-stress acoustic time calibration to determine the zero-stress acoustic time value; the zero-stress sample is subjected to stress coefficient calibration to determine the acoustoelastic coefficient.

[0009] Within a second preset temperature range, ultrasonic testing is performed on the ceramic material component to be tested to obtain the target acoustic time value;

[0010] Based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the target acoustic time value, the residual stress value of the electrical porcelain material component to be tested is determined.

[0011] In one possible implementation, the zero-stress acoustic time value includes the zero-stress longitudinal wave acoustic time value and the zero-stress transverse wave acoustic time value;

[0012] The process of performing zero-stress acoustic time calibration on the zero-stress specimen to determine the zero-stress acoustic time value includes:

[0013] The zero-stress tensile specimen or the zero-stress compression specimen is subjected to ultrasonic longitudinal wave detection and ultrasonic transverse wave detection, respectively, to determine the acoustic time value of the zero-stress longitudinal wave and the acoustic time value of the zero-stress transverse wave.

[0014] In one possible implementation, the step of calibrating the stress coefficient of the zero-stress specimen to determine the acoustoelastic coefficient includes:

[0015] The zero-stress specimen is subjected to ultrasonic testing and stress testing simultaneously to determine the acoustic stress coefficient, which includes the longitudinal wave acoustic stress coefficient and the transverse wave acoustic stress coefficient.

[0016] Based on the zero-stress acoustic time value and the acoustic stress coefficient, the acoustoelastic coefficient is determined, and the acoustoelastic coefficient includes the longitudinal wave acoustoelastic coefficient and the transverse wave acoustoelastic coefficient.

[0017] In one possible implementation, simultaneously performing ultrasonic testing and stress testing on the zero-stress specimen to determine the acoustic stress coefficient includes:

[0018] The zero-stress tensile specimen was subjected to ultrasonic testing and tensile stress test simultaneously to determine the tensile stress value versus longitudinal wave acoustic time difference coordinate curve and the tensile stress value versus transverse wave acoustic time difference coordinate curve.

[0019] The zero-stress compression specimen was simultaneously subjected to ultrasonic testing and compression stress testing to determine the compression stress value versus longitudinal wave acoustic time difference coordinate curve and the compression stress value versus transverse wave acoustic time difference coordinate curve.

[0020] Based on the tensile stress value and the longitudinal wave acoustic time difference coordinate curve and the compressive stress value and the longitudinal wave acoustic time difference coordinate curve, a linear equation for longitudinal wave stress and acoustic time difference is obtained by fitting; based on the tensile stress value and the transverse wave acoustic time difference coordinate curve and the compressive stress value and the transverse wave acoustic time difference coordinate curve, a linear equation for transverse wave stress and acoustic time difference is obtained by fitting.

[0021] Based on the linear equation of longitudinal wave stress and acoustic time difference, the longitudinal wave acoustic stress coefficient is determined; based on the linear equation of transverse wave stress and acoustic time difference, the transverse wave acoustic stress coefficient is determined.

[0022] In one possible implementation, the simultaneous ultrasonic testing and tensile stress testing of the zero-stress tensile specimen to determine the tensile stress value versus longitudinal wave acoustic time-of-flight curve and the tensile stress value versus transverse wave acoustic time-of-flight curve includes:

[0023] A first predetermined number of first test points are selected in the zero-stress tensile specimen;

[0024] A first preset number of tensile forces are applied to each of the first test points, each tensile force corresponding to a different tensile force value. The longitudinal wave acoustic time difference, transverse wave acoustic time difference, and tensile stress change value are collected each time the tensile force is applied.

[0025] Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and tensile stress change value at each time tensile force is applied at each of the first test points, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target tensile stress change value at each of the first test points are determined.

[0026] Based on the target longitudinal wave acoustic transit time and target tensile stress change value at each of the first test points, the coordinate curve of the tensile stress value versus longitudinal wave acoustic transit time is determined. Based on the target transverse wave acoustic transit time and target tensile stress change value at each of the first test points, the coordinate curve of the tensile stress value versus transverse wave acoustic transit time is determined.

[0027] In one possible implementation, the simultaneous ultrasonic testing and compressive stress testing of the zero-stress compression specimen to determine the compressive stress value versus longitudinal wave acoustic time-of-flight curve and the compressive stress value versus transverse wave acoustic time-of-flight curve includes:

[0028] A second predetermined number of second test points are selected in the zero-stress compression specimen;

[0029] A second preset number of pressures are applied to each of the second test points, each pressure corresponding to a different pressure value. The longitudinal wave acoustic time difference, transverse wave acoustic time difference, and compressive stress change value are collected each time pressure is applied.

[0030] Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and compressive stress change value at each time pressure is applied at each of the second test points, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target compressive stress change value at each of the second test points are determined.

[0031] Based on the target longitudinal wave acoustic transit time and target compressive stress change value at each of the second test points, the coordinate curve of the compressive stress value versus longitudinal wave acoustic transit time is determined. Based on the target transverse wave acoustic transit time and target compressive stress change value at each of the second test points, the coordinate curve of the compressive stress value versus transverse wave acoustic transit time is determined.

[0032] In one possible implementation, determining the acoustoelastic coefficient based on the zero-stress acoustic time value and the acoustic stress coefficient includes:

[0033] The longitudinal wave acoustic time value and the longitudinal wave acoustic stress coefficient are used to determine the longitudinal wave acoustic elastic coefficient.

[0034] The shear wave acoustic elastic coefficient is determined based on the zero-pressure shear wave acoustic time value and the shear wave acoustic stress coefficient.

[0035] In one possible implementation, the method further includes:

[0036] During the zero-stress acoustic time calibration of the zero-stress specimen, the first temperature value of the zero-stress specimen is collected.

[0037] During ultrasonic testing of the electrical porcelain material component under test, a second temperature value of the electrical porcelain material component under test is collected.

[0038] When the difference between the first temperature and the second temperature is within a preset temperature difference range, temperature compensation is performed on the target acoustic time value based on the first temperature value and the second temperature value to determine the corrected acoustic time value of the electrical porcelain material component to be tested.

[0039] The residual stress value of the electrical porcelain material component under test is determined based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the corrected acoustic time value.

[0040] Secondly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method as described in the first aspect or any of the implementations thereof.

[0041] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method as described in the first aspect or any of the implementations thereof.

[0042] Fourthly, embodiments of this application provide a computer program product that, when run on an electronic device, causes the electronic device to execute the method described in the first aspect or any of its implementations.

[0043] The beneficial effects of this application embodiment compared with the prior art are as follows: Within a first preset temperature range, zero-stress samples are calibrated using zero-stress acoustic time to determine the zero-stress acoustic time value; the stress coefficient of the zero-stress samples is calibrated to determine the acoustoelastic coefficient; within a second preset temperature range, ultrasonic testing is performed on the porcelain material component to be tested to obtain the target acoustic time value; based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the target acoustic time value, the residual stress value of the porcelain material component to be tested is determined, realizing the residual stress detection of porcelain materials, effectively assessing their safety under service conditions, thereby strengthening the quality monitoring of porcelain materials during grid connection and operation and maintenance, and effectively ensuring the safe and stable operation of the power grid; in addition, calibrating the zero-stress samples and performing ultrasonic testing on the porcelain material component to be tested within the preset temperature range avoids the influence of temperature on the test results, improves the accuracy of the calibration results and ultrasonic test results, and thus improves the accuracy of calculating the residual stress value of the porcelain material component to be tested.

[0044] It is understood that the electronic devices, computer-readable storage media, and computer program products provided in the embodiments of this application have the same beneficial effects as the residual stress detection method for electrical porcelain materials described above, and will not be repeated here. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic flowchart illustrating a method for detecting residual stress in electrical porcelain materials according to an embodiment of this application;

[0047] Figure 2 A schematic diagram of a zero-stress tensile specimen provided in an embodiment of this application;

[0048] Figure 3 A schematic diagram of a zero-stress compression specimen provided in an embodiment of this application;

[0049] Figure 4 This is a schematic diagram of a method for detecting residual stress in electrical porcelain materials, provided as an embodiment of the application. Detailed Implementation

[0050] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0051] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0052] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0053] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0054] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0055] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0056] The residual stress detection method for electrical porcelain materials proposed in this application is based on the principle of acoustoelasticity. The propagation speed of ultrasound in electrical porcelain materials is affected by the internal residual stress. When the direction of residual stress is consistent with the direction of ultrasound propagation, tensile stress slows down the propagation speed or prolongs the propagation time of ultrasound, while compressive stress speeds up the propagation speed or shortens the propagation time of ultrasound. Using a component with known stress and the same material and surface roughness as the electrical porcelain component under test as the stress reference, the tensile and compressive stress state and specific value of the component can be determined by detecting the change in the propagation speed of ultrasound inside the component. The tensile and compressive stress state is usually represented by "+" for tensile stress and "-" for compressive stress.

[0057] For ease of understanding, the technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0058] Figure 1 This is a schematic flowchart illustrating a method for detecting residual stress in electrical porcelain materials according to an embodiment of this application. Figure 1 As shown, for ease of explanation, only the parts relevant to this embodiment are shown. The method provided in this embodiment includes the following steps:

[0059] S1, Obtain a zero-stress specimen of the electrical porcelain material component to be tested. The zero-stress specimen includes a zero-stress tensile specimen and a zero-stress compression specimen.

[0060] In practice, materials with the same material, microstructure, and surface roughness as the electrical porcelain material component to be tested are selected as zero-stress specimens. Since electrical porcelain is a brittle material, zero-stress tensile specimens and zero-stress compression specimens are selected for tensile and compression tests, respectively.

[0061] Preferably, to eliminate stress interference and deviations caused by specimens of other shapes and sizes, a tensile standard specimen is selected as the zero-stress tensile specimen, and its shape and size are as follows: Figure 2 As shown; a standard compression specimen was selected as the zero-stress compression specimen, and its shape and dimensions are as follows. Figure 3 As shown.

[0062] Furthermore, after determining the zero-stress specimen of the electrical porcelain material component to be tested, the zero-stress specimen needs to be subjected to zero-stress treatment, preferably thermal aging or vibration aging. Thermal aging uses repeated annealing heat treatment to relieve stress in the zero-stress specimen. Under the action of heat, internal stress is eliminated through atomic diffusion and plastic deformation. After annealing, the microstructure of the zero-stress specimen should be the same as that of the electrical porcelain material component to be tested. Vibration aging applies additional stress to the zero-stress specimen through vibration, causing the specimen to resonate. When the additional stress and residual stress are superimposed and reach or exceed the yield point of the material, microscopic and macroscopic plastic deformation occurs inside the zero-stress specimen, thereby eliminating residual stress.

[0063] Optionally, parameter settings for each device in the ultrasonic residual stress detection system also need to be configured, such as... Figure 4 As shown, an ultrasonic residual stress detection system should at least include an ultrasonic body wave probe, a longitudinal wave transducer, a transverse wave transducer, a stress calculation system (not shown in the figure), a temperature sensor (not shown in the figure), a coupling agent, and a fixture (not shown in the figure).

[0064] As an example, based on the material, acoustic properties, size and shape, and detection area of ​​the electrical ceramic component under test, parameters such as the center frequency and emitting surface area of ​​the ultrasonic bulk wave probe are set to ensure good coupling between the probe and the contact surface of the component under test, so as to ensure that effective ultrasonic longitudinal and transverse waves can be obtained in the direction of sound wave propagation.

[0065] As an example, during the test, the temperature sensor needs to be attached near the ultrasonic body wave probe to accurately obtain the actual temperature of the component under test.

[0066] As an example, auxiliary fixtures are used during the test to ensure that the coupling state between the tested ceramic material component and the zero-stress specimen remains consistent in subsequent processes.

[0067] S2, within the first preset temperature range, perform zero-stress acoustic time calibration on the zero-stress sample to determine the zero-stress acoustic time value; perform stress coefficient calibration on the zero-stress sample to determine the acoustoelastic coefficient.

[0068] In specific implementation, the first preset temperature range is preferably 18℃~28℃. Tensile tests are performed on the specimens within the elastic deformation range of the material according to the method specified in GB / T 228.1; and compression tests are performed on the specimens within the compressive strength range of the material according to the method specified in GB / T 7314.

[0069] In one possible implementation, the zero-stress acoustic time value includes the zero-stress longitudinal wave acoustic time value and the zero-stress transverse wave acoustic time value; therefore, the step of calibrating the zero-stress sample using zero-stress acoustic time to determine the zero-stress acoustic time value may optionally include:

[0070] For zero-stress tensile specimens or zero-stress compression specimens, ultrasonic longitudinal wave testing and ultrasonic transverse wave testing are performed respectively to determine the acoustic time values ​​of zero-stress longitudinal wave and zero-stress transverse wave.

[0071] As an example, for zero-stress tensile or zero-stress compression specimens, ultrasonic longitudinal wave testing and ultrasonic transverse wave testing are performed respectively, and the acoustic time value T of the zero-stress longitudinal wave is directly measured. zo and zero-stress transverse wave acoustic time value T ho .

[0072] In one possible implementation, the step of calibrating the stress coefficient of the zero-stress specimen to determine the acoustoelastic coefficient may include:

[0073] S21, simultaneously perform ultrasonic testing and stress testing on the zero-stress sample to determine the acoustic stress coefficient, which includes the longitudinal wave acoustic stress coefficient and the transverse wave acoustic stress coefficient.

[0074] As an example, step S21 may optionally include:

[0075] S211, simultaneously perform ultrasonic testing and tensile stress test on zero-stress tensile specimens to determine the coordinate curves of tensile stress value versus longitudinal wave acoustic time difference and tensile stress value versus transverse wave acoustic time difference.

[0076] For example, step S211 may optionally include:

[0077] Select a first predetermined number of first test points in a zero-stress tensile specimen;

[0078] A first preset number of tensile forces are applied at each first test point, with each tensile force corresponding to a different tensile force value. The longitudinal wave acoustic time difference, transverse wave acoustic time difference, and tensile stress change value are collected each time the tensile force is applied.

[0079] Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and tensile stress change value at each time tensile force is applied at each first test point, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target tensile stress change value at each first test point are determined.

[0080] Based on the target longitudinal wave acoustic transit time and target tensile stress change value at each first test point, the coordinate curve of tensile stress value versus longitudinal wave acoustic transit time is determined. Based on the target transverse wave acoustic transit time and target tensile stress change value at each first test point, the coordinate curve of tensile stress value versus transverse wave acoustic transit time is determined.

[0081] Preferably, the first preset quantity is greater than or equal to 10, and the first preset number of times is greater than or equal to 5. These can be customized according to actual conditions, and this application does not limit them.

[0082] For example, 10 first test points are selected in a zero-stress tensile specimen, and a tensile force is applied to each first test point 5 times, with the standard tensile stress increasing by 5 MPa each time. The longitudinal wave acoustic transit time Δt is collected at each application of tensile force. z1 Transverse wave acoustic time difference Δt h1The tensile stress change value Δσ1 output by the tensile testing machine is used to calculate the average value of 5 measurements for each first test point. The target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target tensile stress change value for each first test point are determined. Based on the target longitudinal wave acoustic transit time and target tensile stress change value corresponding to the 10 first test points, the coordinate curves of tensile stress value and longitudinal wave acoustic transit time are plotted. Based on the target transverse wave acoustic transit time and target tensile stress change value for the 10 first test points, the coordinate curves of tensile stress value and transverse wave acoustic transit time are plotted.

[0083] S212, simultaneously perform ultrasonic testing and compressive stress testing on zero-stress compression specimens to determine the compressive stress value versus longitudinal wave acoustic time difference coordinate curve and the compressive stress value versus transverse wave acoustic time difference coordinate curve.

[0084] For example, step S212 may optionally include:

[0085] Select a second predetermined number of second test points in the zero-stress compression specimen;

[0086] Apply pressure for a second preset number of times at each second test point. Each pressure corresponds to a different pressure value. Collect the longitudinal wave acoustic time difference, transverse wave acoustic time difference and compressive stress change value at each time pressure is applied.

[0087] Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and compressive stress change value at each time pressure is applied at each second test point, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target compressive stress change value at each second test point are determined.

[0088] Based on the target longitudinal wave acoustic time difference and target compressive stress change value at each second test point, the coordinate curve of compressive stress value versus longitudinal wave acoustic time difference is determined. Based on the target transverse wave acoustic time difference and target compressive stress change value at each second test point, the coordinate curve of compressive stress value versus transverse wave acoustic time difference is determined.

[0089] Preferably, the second preset quantity is greater than or equal to 10, and the second preset number of times is greater than or equal to 5. These can be customized according to actual conditions, and this application does not limit them.

[0090] For example, 10 second test points are selected in the zero-stress compression specimen, and stress is applied 5 times to each second test point, with the standard compressive stress increasing by 5 MPa each time. The longitudinal wave acoustic transit time Δt is collected for each applied pressure. z2 Transverse wave acoustic time difference Δt h2The compressive stress change value Δσ2 output by the tensile testing machine is used. For each second test point, the average value of 5 measurements is taken to determine the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target compressive stress change value for each second test point. Based on the target longitudinal wave acoustic transit time and target compressive stress change value corresponding to the 10 second test points, the compressive stress value and longitudinal wave acoustic transit time coordinate curve are plotted. Based on the target transverse wave acoustic transit time and target compressive stress change value for the 10 second test points, the compressive stress value and transverse wave acoustic transit time coordinate curve are plotted.

[0091] S213, based on the coordinate curves of tensile stress value and longitudinal wave acoustic time difference and compressive stress value and longitudinal wave acoustic time difference, a linear equation of longitudinal wave stress and acoustic time difference is obtained by fitting; based on the coordinate curves of tensile stress value and transverse wave acoustic time difference and compressive stress value and transverse wave acoustic time difference, a linear equation of transverse wave stress and acoustic time difference is obtained by fitting.

[0092] As an example, the linear equations of longitudinal wave stress and acoustic time difference obtained by fitting are shown in Equation (1), and the linear equations of transverse wave stress and acoustic time difference are shown in Equation (2):

[0093] Δσ z =k z0 Δt z0 +T zo (1)

[0094] Δσ h =k h0 Δt h0 +T ho (2)

[0095] Where, Δσ z Let Δσ be the tensile / compressive stress applied under the longitudinal wave velocity, and the longitudinal wave stress. h The tensile / compressive stress applied under transverse wave sound velocity, i.e., transverse wave stress, where "+" indicates tensile stress and "-" indicates compressive stress, with units of MPa; Δt z0 Let Δt be the acoustic time difference of the longitudinal wave. h0 T represents the acoustic time difference of a transverse wave, where "+" indicates a longer propagation time and "-" indicates a shorter propagation time, measured in nanoseconds (ns). zo The zero-stress longitudinal wave acoustic time value, T ho The zero-stress transverse wave acoustic time value is expressed in nanoseconds (ns).

[0096] S214. Based on the linear equation of longitudinal wave stress and acoustic time difference, the longitudinal wave acoustic stress coefficient is determined; based on the linear equation of transverse wave stress and acoustic time difference, the transverse wave acoustic stress coefficient is determined.

[0097] In practical implementation, the linear equation of longitudinal wave stress and acoustic time difference is shown in formula (1), where k z0This is the longitudinal wave acoustic stress coefficient, with units of megapascals per nanosecond (MPa / ns); as shown in formula (2), the linear equation of transverse wave stress and acoustic time difference is given, where k h0 This is the transverse wave acoustic stress coefficient, with units of MPa / ns.

[0098] S22, based on the zero-stress acoustic time value and acoustic stress coefficient, the acoustic elastic coefficient is determined. The acoustic elastic coefficient includes the longitudinal wave acoustic elastic coefficient and the transverse wave acoustic elastic coefficient.

[0099] As an example, step S22 may optionally include:

[0100] The longitudinal wave acoustic elastic coefficient is determined based on the zero-pressure longitudinal wave acoustic time value and the longitudinal wave acoustic stress coefficient.

[0101] The transverse wave acoustic elastic coefficient is determined based on the zero-pressure transverse wave acoustic time value and the transverse wave acoustic stress coefficient.

[0102] For example, based on the zero-pressure longitudinal wave acoustic time value T zo and longitudinal wave acoustic stress coefficient k z0 Through formula Calculate the longitudinal wave acoustic elastic coefficient ε z Its unit is megapascals (MPa) -1 ).

[0103] For example, based on the zero-pressure shear wave acoustic time value T ho and transverse wave acoustic stress coefficient k h0 Through formula Calculate the transverse wave acoustic elastic coefficient ε h Its unit is megapascals (MPa) -1 ).

[0104] S3, within the second preset temperature range, perform ultrasonic testing on the ceramic material component to be tested to obtain the target acoustic time value.

[0105] Optionally, before performing ultrasonic testing on the ceramic material component to be tested, the surface of the ceramic material component to be tested should be checked to ensure that it is clean and free of contaminants. The coupling state between the ultrasonic bulk wave probe and the surface of the ceramic material component to be tested should be basically consistent with the coupling state when calibrating the zero-stress acoustic time and stress coefficient of the zero-stress sample.

[0106] In specific implementation, within the second preset temperature range, when the coupling state is stable, the bulk wave detection instrument starts detection. On the basis of ensuring clear bulk wave echoes, the waveband with the echo peak value between 60% and 80% of the full scale of the bulk wave detection instrument is selected, and the target acoustic time value of the electrical porcelain material component to be tested is calculated, including the target longitudinal wave acoustic time value and the target transverse wave acoustic time value.

[0107] For example, the second preset temperature range can be the same as the first preset temperature range, i.e., 18℃~28℃; or when calibrating the zero-stress sample with zero-stress acoustic time, the actual temperature value of the zero-stress sample can be collected by a temperature sensor, and the actual temperature value ±15℃ can be used as the second preset temperature range.

[0108] S4. Based on the zero-stress acoustic time value, the acoustic elastic coefficient, and the target acoustic time value, determine the residual stress value of the electrical porcelain material component to be tested.

[0109] As an example, based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the target acoustic time value, the residual stress value of the electrical porcelain material component under test is calculated using formula (3):

[0110]

[0111] Where σ is the residual stress value of the electrical porcelain material component under test, in MPa, and ε z ε is the longitudinal wave acoustic elastic coefficient. h T is the transverse wave acoustic elastic coefficient. zo The zero-stress longitudinal wave acoustic time value, T ho The zero-stress transverse wave acoustic time value, T z T represents the target longitudinal wave acoustic time value of the electrical porcelain material component to be tested. h The target transverse wave acoustic time value is the electrical porcelain material component to be tested.

[0112] In one possible implementation, the following steps may also be included:

[0113] When calibrating the zero-stress specimen using zero-stress acoustic time, the first temperature value of the zero-stress specimen is collected.

[0114] When performing ultrasonic testing on the electrical porcelain material component under test, the second temperature value of the electrical porcelain material component under test is collected.

[0115] When the difference between the first temperature and the second temperature is within the preset temperature difference range, the target acoustic time value is compensated for based on the first temperature value and the second temperature value to determine the corrected acoustic time value of the electrical porcelain material component to be tested.

[0116] The residual stress value of the electrical porcelain material component under test is determined based on the zero-stress acoustic time value, the acoustic elastic coefficient, and the corrected acoustic time value.

[0117] Optionally, a temperature sensor is attached near the bulk wave detection probe. When calibrating the zero-stress sample using zero-stress acoustic time, the actual temperature of the zero-stress sample is collected and recorded as the first temperature value. When performing ultrasonic testing on the ceramic material component under test, the actual temperature of the ceramic material component under test is collected and recorded as the second temperature value. The measurement accuracy meets or exceeds Class A. When the difference between the first temperature and the second temperature is within a preset temperature difference range, temperature compensation is performed on the target acoustic time value based on the first and second temperature values ​​to determine the corrected acoustic time value of the ceramic material component under test. If the difference between the first temperature value and the second temperature value exceeds the preset temperature difference range, the zero-stress sample is recalibrated.

[0118] As an example, the preset temperature difference range is [-15℃, 0) ∪ (0, 15℃], that is, the first temperature and the second temperature are different and their difference is within ±15℃.

[0119] As an example, temperature compensation can be achieved by adjusting the operating status of the equipment using methods such as manual temperature compensation, automatic temperature compensation, thermistor temperature compensation, and thermocouple temperature compensation.

[0120] Preferably, based on the first and second temperature values, the target acoustic time value is temperature-compensated using formula (4) to determine the corrected acoustic time value of the electrical porcelain material component under test:

[0121] X true =X meas (T)-[K1(T-T0)+K2(T-T0) 2 (4)

[0122] Among them, X true To correct the acoustic time values, including correcting the longitudinal wave acoustic time values ​​and correcting the transverse wave acoustic time values, X meas (T) represents the target acoustic time value, T represents the second temperature value, T0 represents the first temperature value, and K1 and K2 are preset correction parameters that can be obtained experimentally based on actual conditions. This application does not limit these parameters.

[0123] Furthermore, after obtaining the corrected acoustic time value of the electrical porcelain material component to be tested, the residual stress value of the electrical porcelain material component to be tested is calculated based on the zero stress acoustic time value, the acoustic elastic coefficient and the corrected acoustic time value, according to formula (3). The target longitudinal wave acoustic time value in the formula is replaced with the corrected longitudinal wave acoustic time value, and the target transverse wave acoustic time value is replaced with the corrected transverse wave acoustic time value for calculation.

[0124] The technical solution provided in this embodiment effectively avoids the impact of a large temperature difference between calibration and testing on the test results, and improves the accuracy of detecting the residual stress value of the electrical porcelain material component under test.

[0125] The technical solution provided in this embodiment involves: calibrating the zero-stress sample using zero-stress acoustic time within a first preset temperature range to determine the zero-stress acoustic time value; calibrating the stress coefficient of the zero-stress sample to determine the acoustoelastic coefficient; and performing ultrasonic testing on the porcelain material component under test within a second preset temperature range to obtain the target acoustic time value. Based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the target acoustic time value, the residual stress value of the porcelain material component under test is determined. This achieves residual stress detection of the porcelain material, effectively assesses its safety under service conditions, strengthens quality monitoring of porcelain materials during grid connection and operation and maintenance, and effectively ensures the safe and stable operation of the power grid. Furthermore, calibrating the zero-stress sample and performing ultrasonic testing on the porcelain material component under test within the preset temperature range avoids the influence of temperature on the test results, improves the accuracy of the calibration and ultrasonic test results, and thus enhances the accuracy of calculating the residual stress value of the porcelain material component under test.

[0126] On the other hand, this application also provides a computer storage medium storing executable program code; the executable program code is used to execute the residual stress detection method for any of the above-mentioned electrical porcelain materials.

[0127] On the other hand, this application also provides an electronic device, including a memory and a processor; the memory stores program code that can be executed by the processor; the program code is used to execute the residual stress detection method for any of the above-mentioned electrical ceramic materials.

[0128] For example, the program code may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the program code in an electronic device.

[0129] The electronic device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The electronic device may include, but is not limited to, processors and memory. Those skilled in the art will understand that the electronic device may also include input / output devices, network access devices, buses, etc.

[0130] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0131] The memory can be an internal storage unit of the electronic device, such as a hard drive or RAM. It can also be an external storage device, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory can include both internal and external storage units. The memory is used to store the program code and other programs and data required by the electronic device. The memory can also be used to temporarily store data that has been output or will be output.

[0132] The computer storage medium and electronic device described above are created based on the above method. Their technical functions and beneficial effects will not be elaborated here. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for detecting residual stress in electrical porcelain materials, characterized in that, The method includes: Obtain zero-stress specimens of the electrical porcelain material components to be tested, including zero-stress tensile specimens and zero-stress compression specimens. Within a first preset temperature range, the zero-stress sample is subjected to zero-stress acoustic time calibration to determine the zero-stress acoustic time value; the zero-stress sample is subjected to stress coefficient calibration to determine the acoustoelastic coefficient. Within a second preset temperature range, ultrasonic testing is performed on the ceramic material component to be tested to obtain the target acoustic time value; Based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the target acoustic time value, the residual stress value of the electrical porcelain material component to be tested is determined.

2. The method according to claim 1, characterized in that, The zero-stress acoustic time value includes the zero-stress longitudinal wave acoustic time value and the zero-stress transverse wave acoustic time value; The process of performing zero-stress acoustic time calibration on the zero-stress specimen to determine the zero-stress acoustic time value includes: The zero-stress tensile specimen or the zero-stress compression specimen is subjected to ultrasonic longitudinal wave detection and ultrasonic transverse wave detection, respectively, to determine the acoustic time value of the zero-stress longitudinal wave and the acoustic time value of the zero-stress transverse wave.

3. The method according to claim 1, characterized in that, The step of calibrating the stress coefficient of the zero-stress specimen to determine the acoustoelastic coefficient includes: The zero-stress specimen is subjected to ultrasonic testing and stress testing simultaneously to determine the acoustic stress coefficient, which includes the longitudinal wave acoustic stress coefficient and the transverse wave acoustic stress coefficient. Based on the zero-stress acoustic time value and the acoustic stress coefficient, the acoustoelastic coefficient is determined, and the acoustoelastic coefficient includes the longitudinal wave acoustoelastic coefficient and the transverse wave acoustoelastic coefficient.

4. The method according to claim 3, characterized in that, The step of simultaneously performing ultrasonic testing and stress testing on the zero-stress sample to determine the acoustic stress coefficient includes: The zero-stress tensile specimen was subjected to ultrasonic testing and tensile stress test simultaneously to determine the tensile stress value versus longitudinal wave acoustic time difference coordinate curve and the tensile stress value versus transverse wave acoustic time difference coordinate curve. The zero-stress compression specimen was simultaneously subjected to ultrasonic testing and compression stress testing to determine the compression stress value versus longitudinal wave acoustic time difference coordinate curve and the compression stress value versus transverse wave acoustic time difference coordinate curve. Based on the tensile stress value and the longitudinal wave acoustic time difference coordinate curve and the compressive stress value and the longitudinal wave acoustic time difference coordinate curve, a linear equation for longitudinal wave stress and acoustic time difference is obtained by fitting; based on the tensile stress value and the transverse wave acoustic time difference coordinate curve and the compressive stress value and the transverse wave acoustic time difference coordinate curve, a linear equation for transverse wave stress and acoustic time difference is obtained by fitting. Based on the linear equation of longitudinal wave stress and acoustic time difference, the longitudinal wave acoustic stress coefficient is determined; based on the linear equation of transverse wave stress and acoustic time difference, the transverse wave acoustic stress coefficient is determined.

5. The method according to claim 4, characterized in that, The simultaneous ultrasonic testing and tensile stress test on the zero-stress tensile specimen to determine the tensile stress value versus longitudinal wave acoustic time-of-flight coordinate curve and the tensile stress value versus transverse wave acoustic time-of-flight coordinate curve includes: A first predetermined number of first test points are selected in the zero-stress tensile specimen; A first preset number of tensile forces are applied to each of the first test points, each tensile force corresponding to a different tensile force value. The longitudinal wave acoustic time difference, transverse wave acoustic time difference, and tensile stress change value are collected each time the tensile force is applied. Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and tensile stress change value at each time tensile force is applied at each of the first test points, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target tensile stress change value at each of the first test points are determined. Based on the target longitudinal wave acoustic transit time and target tensile stress change value at each of the first test points, the coordinate curve of the tensile stress value versus longitudinal wave acoustic transit time is determined. Based on the target transverse wave acoustic transit time and target tensile stress change value at each of the first test points, the coordinate curve of the tensile stress value versus transverse wave acoustic transit time is determined.

6. The method according to claim 4, characterized in that, The simultaneous ultrasonic testing and compressive stress testing of the zero-stress compression specimen to determine the compressive stress value versus longitudinal wave acoustic time-of-flight coordinate curve and the compressive stress value versus transverse wave acoustic time-of-flight coordinate curve includes: A second predetermined number of second test points are selected in the zero-stress compression specimen; A second preset number of pressures are applied to each of the second test points, each pressure corresponding to a different pressure value. The longitudinal wave acoustic time difference, transverse wave acoustic time difference, and compressive stress change value are collected each time pressure is applied. Based on the longitudinal wave acoustic transit time, transverse wave acoustic transit time, and compressive stress change value at each time pressure is applied at each of the second test points, the target longitudinal wave acoustic transit time, target transverse wave acoustic transit time, and target compressive stress change value at each of the second test points are determined. Based on the target longitudinal wave acoustic transit time and target compressive stress change value at each of the second test points, the coordinate curve of the compressive stress value versus longitudinal wave acoustic transit time is determined. Based on the target transverse wave acoustic transit time and target compressive stress change value at each of the second test points, the coordinate curve of the compressive stress value versus transverse wave acoustic transit time is determined.

7. The method according to claim 3, characterized in that, The determination of the acoustoelastic coefficient based on the zero-stress acoustic time value and the acoustic stress coefficient includes: The longitudinal wave acoustic time value and the longitudinal wave acoustic stress coefficient are used to determine the longitudinal wave acoustic elastic coefficient. The shear wave acoustic elastic coefficient is determined based on the zero-pressure shear wave acoustic time value and the shear wave acoustic stress coefficient.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: During the zero-stress acoustic time calibration of the zero-stress specimen, the first temperature value of the zero-stress specimen is collected. During ultrasonic testing of the electrical porcelain material component under test, a second temperature value of the electrical porcelain material component under test is collected. When the difference between the first temperature and the second temperature is within a preset temperature difference range, temperature compensation is performed on the target acoustic time value based on the first temperature value and the second temperature value to determine the corrected acoustic time value of the electrical porcelain material component to be tested. The residual stress value of the electrical porcelain material component under test is determined based on the zero-stress acoustic time value, the acoustoelastic coefficient, and the corrected acoustic time value.

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

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

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