Ultrasonic method for stress high-resolution measurement based on sliding window, storage medium and device

Abstract

This invention relates to a high-resolution ultrasonic stress measurement method, storage medium, and device based on a sliding window, belonging to the field of stress measurement technology. It addresses the limitations of existing ultrasonic methods, such as the inability to measure stress in millimeter-level regions due to probe size constraints and low stress resolution. The invention divides the component surface into N micro-regions with a spacing of Δ, marked by lines. Two ultrasonic probes with a size difference of Δ move along the marked lines in steps of Δ. The stress measurements taken at a single measuring point by the small and large ultrasonic probes are recorded as follows: the stress values ​​measured at n-1 locations from the same starting position by the large and small probes are subtracted to obtain the stress in multiple micro-regions, serving as initial conditions. These initial conditions are then used as known quantities, and the stress value for each micro-region is calculated based on the stress and relationships within each micro-region.

Description

Technical Field

[0001] This invention belongs to the field of stress measurement technology, and relates to an ultrasonic method for measuring stress in millimeter-level regions, as well as a storage medium and device. Background Technology

[0002] Residual stress significantly impacts the service reliability of structural components, being a major factor contributing to fracture, fatigue failure, and stress corrosion. It has gradually become a crucial parameter in structural component quality assessment. The principle of ultrasonic stress measurement is based on the acoustoelastic effect, where stress in a material alters the propagation speed of ultrasonic waves. By measuring the propagation speed or frequency changes of ultrasonic waves within a component, the magnitude and distribution of internal residual stress can be deduced. However, the size of ultrasonic probes is limited by manufacturing processes and the equipment's ability to capture ultrasonic signals, preventing further miniaturization. Existing ultrasonic methods can only obtain the average stress within the probe's coverage area, failing to accurately measure stress at specific, minute locations. While ultrasonic measurements based on the "displacement difference" method employ variable-sized "one-transmitter-one-receiver" probes to measure stress over smaller areas, they still cannot calculate stress over a 1mm x 1mm area. Summary of the Invention

[0003] This invention aims to solve the problems of existing ultrasonic methods, such as the inability to measure stress in millimeter-level areas due to probe size limitations and low stress resolution.

[0004] A high-resolution ultrasonic stress measurement method based on a sliding window includes:

[0005] S1. Obtain stress measurements at one measuring point using small and large ultrasonic probes. and ; obtained and It was obtained in the following way:

[0006] Marking lines are made on the surface of the component to discretize the measurement path into N tiny regions, with a spacing Δ. Two ultrasonic probes with a size difference of Δ are used to move along the marking lines in steps of Δ. The stress measurements at a single measuring point using the small and large ultrasonic probes are recorded as follows: and ;

[0007] S2. Subtract the stress values ​​measured at n-1 locations with large and small probes at the same starting position to obtain the stress in multiple micro-regions. The initial condition is used as the initial condition; the stress value of each micro-region is calculated based on the stress and relationship of different micro-regions, using the initial condition as a known quantity.

[0008] Furthermore, the small-area stress of the initial conditions in step S2 , .

[0009] Furthermore, in step S2, the stress values ​​measured at n-1 locations by the large and small probes at the same starting position are subtracted to obtain the stress in multiple micro-regions. The process includes:

[0010] Subtract the equations for the large and small probes that correspond to the same starting position:

[0011] ,

[0012] The left side is simplified to obtain ;

[0013] The same method is used to directly obtain n-1 stress values: .

[0014] Furthermore, the stress and relationship of each micro-region are calculated based on the stress and relationship of different micro-regions. , , This represents the sum of the sliding stresses within the sliding window corresponding to positions i and i+1. This represents the stress value of the first tiny region of the sliding window corresponding to the i-th position. This represents the stress value of the last tiny region of the sliding window corresponding to the (i+1)th position.

[0015] Furthermore, the process of calculating the stress value of each micro-region based on the stress and relationship of different micro-regions, using the initial conditions as known quantities, includes:

[0016] First, use large and small probe differences to indicate The movement difference of the large probe is used to represent it. By taking the initial conditions as known quantities, the stress value of the small region that can be calculated using the known quantities is obtained based on the stress and relationship of the small region.

[0017] Then, using the calculated stress value of the micro-region as a known quantity, the stress difference of the micro-region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. This allows us to obtain the stress value for each tiny region.

[0018] Furthermore, the stress difference in a small region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. , M represents the number of positions that the large-size probe can effectively measure.

[0019] Furthermore, the stress difference in the micro-region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. The process includes:

[0020] First, the theoretical measurement equation for the large-size probe is determined: the large-size probe measures the stress in each region along the marked line, with the same step size as the small-size probe. It is assumed that the large-size probe can measure n tiny regions at one measurement point; the measured value at the i-th measurement point is denoted as... ;

[0021] Then, for large-size probes, subtract the (i+1)th equation from the ith equation:

[0022] ,

[0023] The left side is simplified to Furthermore, the stress at the (i+1)th measurement position and the i-th measurement position of the large-size probe yields the stress difference in a small region.

[0024] Furthermore, during the measurement process of moving along the marked line with a step size of Δ using two ultrasonic probes of different sizes with a size difference of Δ, only the smaller probe is used to measure n-1 positions.

[0025] A computer storage medium storing at least one instruction, which is loaded and executed by a processor to implement the aforementioned high-resolution ultrasonic stress measurement method based on a sliding window.

[0026] A sliding window-based ultrasonic high-resolution stress measurement device includes a processor and a memory. The memory stores at least one instruction, which is loaded and executed by the processor to implement the sliding window-based ultrasonic high-resolution stress measurement method.

[0027] The advantages of this invention compared to the prior art are as follows:

[0028] By using a multi-size probe data difference and sliding summation model, the limitations of ultrasonic probe size can be overcome, enabling precise measurement of millimeter-level regions and improving stress resolution. This invention uses actual measured boundary stress values ​​as constraints, enhancing the stability and accuracy of the model calculations and resulting in good measurement precision. This invention can be performed using conventional ultrasonic equipment without requiring customized probes, thus increasing its practicality. In principle, this invention is applicable to any material that can be measured by ultrasonic methods, calculating stress in millimeter-level regions, and has a wide range of applications. Attached Figure Description

[0029] Figure 1This is a schematic diagram showing measurements taken with two different probes. Detailed Implementation

[0030] To address the technical problems in the background art, this invention proposes a high-resolution ultrasonic stress measurement method based on a sliding window. This method utilizes ultrasonic methods to measure stress in millimeter-level regions. By combining probes of different sizes with the difference method and the sliding window summation model, the limitation of probe size on measurement accuracy is overcome, enabling precise measurement of stress in millimeter-level regions.

[0031] Specific implementation method one: Combining Figure 1 This implementation method is described below.

[0032] This embodiment describes a high-resolution ultrasonic stress measurement method based on a sliding window, comprising:

[0033] A coordinate system is established with the direction of ultrasonic probe movement on the component surface as the x-axis and the direction of probe movement inside the component (which is also the ultrasonic emission direction) perpendicular to the x-axis as the y-axis. Measurements are performed on the same area using two ultrasonic probes of different sizes in the x-direction. Based on the differences in measurement data from the two probes and the derivation of a sliding window summation model, the stress Y in the probe-covered area is calculated. L,i By disassembling the probe, the stress distribution in areas smaller than the probe size can be deduced:

[0034] The value measured by each ultrasonic probe of different sizes is the result of the combined stress in all areas covered by the probe, which can be understood as an average value. The measurement path is discretized into many continuous micro-regions (similar to windows), and ultrasonic probe measurement data Y is established. L,i and the stress σ in each small region i The relationship between them, and the difference σ obtained by combining the measurement results of probes of different sizes. j The stress value of each millimeter-level region can be obtained through a sliding window summation model. A large-size probe measures stress at all locations along the measurement path. According to the characteristics of the sliding summation model, n-1 initial values ​​are needed as initial conditions to ensure that each window value has a unique value. Therefore, a small probe with a size difference of Δ from the large probe is used to measure any n-1 locations, meaning the small probe slides only n-1 times. The difference between the measurements from the large and small probes yields the initial value for obtaining a unique solution in the sliding summation model. Substituting this initial value into the summation formula allows the calculation of the stress value for each tiny region. This method, which uses a large probe to measure the entire region and a small probe to assist in obtaining initial values, improves the efficiency of stress measurement and calculation. More specifically, it includes the following steps:

[0035] S1. Mark the surface of the component with lines to divide the measurement path into N small regions, and denote the spacing as Δ.

[0036] S2. Prepare two types of probes with a size difference of Δ.

[0037] S3. Adjust the size of the ultrasound equipment to enable it to capture a stable waveform.

[0038] S4. A small-sized probe is used to measure stress along the marked line. Assuming the small-sized probe can measure n-1 small areas at one measurement point, the measured value at the j-th measurement point is denoted as Y. S,j :

[0039]

[0040] Where j is the position measured by the small probe; k is the number of discrete small regions; σ k It represents the stress value for each small area.

[0041] S5. The large-size probe measures the stress in each region along the marked line, with the same step size as the small-size probe. Assume the large-size probe can measure n tiny regions at one measurement point; the measurement value at the i-th measurement point is denoted as Y. L,i :

[0042]

[0043] In the formula, M = N - n + 1 represents the number of positions that can be effectively measured by the large-size probe.

[0044] S6. The difference between the stress values ​​measured at n-1 positions by the large and small probes at the same starting position is used as the initial condition for the sliding window summation model, denoted as σ. j :

[0045]

[0046] S7, the sliding sum at the i-th position, denoted as S i :

[0047]

[0048] S8. From the measurement equation of the large probe, we can see that:

[0049]

[0050] S9. The following relationship exists between adjacent sliding sums:

[0051]

[0052] It can then be calculated that:

[0053] .

[0054] Example:

[0055] The high-resolution ultrasonic stress measurement method based on a sliding window described in this embodiment is as follows:

[0056] 1. In order to discretize the area covered by the measurement path into N small regions (σ1, σ2, σ3…σ… N Parallel lines are drawn on the surface of the component to be tested as marker lines, with a spacing of Δ between each marker line (1 mm is used in this embodiment). The marker lines themselves can also serve as guide paths for the probe to move and scan.

[0057] 2. Prepare two ultrasonic probes with different dimensions in the x-direction, with the size difference being the spacing Δ between the marking lines, so that when the two probes measure in the same area, their difference can be directly used as the initial condition for the sliding window summation model.

[0058] 3. Adjust the parameters of the ultrasound equipment to enable it to capture stable waveforms.

[0059] 4. According to the solution of the sliding window summation model, to obtain a unique solution, n-1 definite values ​​are required as constraints. n is the number of windows that a large probe can measure at one measurement point, i.e., the ratio of the lateral dimension of the large probe to the spacing Δ of the marker lines. Therefore, to obtain the accurate residual stress value for each small region, it is necessary to use probes of different sizes (small probes) to obtain n-1 values ​​at n-1 locations and calculate the difference as the initial conditions for model derivation.

[0060] 5. The width of the area covered by the large probe is (i.e., n consecutive small regions). The measurement value at the i-th measurement point is defined as Y. L,i As can be seen from the figure, Y L,i and micro-regional stress σ i The relationship between them is: ,have to AB represents the measurement range of the large probe, i.e., the width of the area it covers; and Substitute (Theoretically, it is the average value of stress within the range). In the formula... M = N - n + 1, which is the number of positions that the large-size probe can effectively measure.

[0061] 6. The width of the area covered by the small probe is And only a small probe is used to measure n-1 locations. The measurement value at the j-th measurement point is defined as Y. S,j : (Theoretically, it is the average value of the stress within the range), where .

[0062] 7. From the above two equations, we can see that the initial condition σ of the sliding window summation model... j for: It should be noted that: here It is the stress in the i-th micro-region in a theoretical sense.

[0063] Define the sliding sum S corresponding to the i-th position. i : , here This represents the actual stress value that a measurement location should have, for example, when i=1, it is from... arrive Summation, i.e., the sum of stresses in these n tiny regions. Combining this with the measurement equation of the large probe, we obtain: This is the measurement value from the large probe. The stress in a small region is represented by the average value of the stress in a small region within the theoretical range, and then summed up by these small regions.

[0064] Therefore, based on the characteristics of the sliding window summation model, we can deduce the following relationship between adjacent sliding sums: This represents the sliding sum corresponding to the (i+1)th position. It is the sliding sum corresponding to the i-th position. Subtract the stress value of the first tiny region within its range (i.e.) Then, add the stress value of the last tiny region within the window corresponding to the (i+1)th position, similar to calculating the sliding sum using a sliding window. During the analysis, the difference between large and small probes is used. to indicate The movement difference of the large probe is used to represent it. .

[0065] 8. S i and S i+1 Based on the probe measurement results and the number of windows, it can be seen that for σ i ,exist The initial condition σ in the relation is known. j (σ) j The form is corresponding In terms of computational form, and specifically regarding the calculated result, when it corresponds to the i-th minute region, it is σ. i , σ j Belongs to all σ i (A portion) can be obtained through the known σ j To calculate σ i+n And continuously use the calculation results as initial conditions and then substitute them into the input. Perform iterations until all σ are obtained. i+n ,Right now .

[0066] The following is an expansion of the above sliding summation process using the addition and subtraction of equations:

[0067] Subtract the equations of the large and small probes corresponding to the same starting position (i=j=1,2,…,n-1):

[0068] ,

[0069] The left side simplifies to σ i+n-1 ,therefore:

[0070] ,

[0071] From this, we can directly obtain n-1 stress values: ;

[0072] For the large probe equations, subtract the (i+1)th equation from the ith equation (i=1,2,…,M-1):

[0073] ,

[0074] The left side is simplified to σ i+n -σ i Therefore

[0075] ,

[0076] Reuse known Find .

[0077] When i=1, , where σ n+1 Known;

[0078] When i=2 , where σ n+2 Known;

[0079] And so on, until i = n - 2, in Known.

[0080] Then, using the first equation of the large probe (i=1): , and thus .

[0081] When i = n-1 ,in Known;

[0082] When i=n ,in Known;

[0083] By analogy, the stress values ​​of all tiny regions can be obtained. Specific Implementation Method Two:

[0085] This embodiment is a computer storage medium that stores at least one instruction, which is loaded and executed by a processor to implement the ultrasonic high-resolution stress measurement method based on a sliding window.

[0086] It should be understood that the instructions include computer program products, software, or computerized methods corresponding to any method described in this invention; the instructions can be used to program computer systems or other electronic devices. Computer storage media may include readable media on which instructions are stored, and may include, but are not limited to, magnetic storage media, optical storage media; magneto-optical storage media include read-only memory (ROM), random access memory (RAM), erasable programmable memory (e.g., EPROM and EEPROM), and flash memory layers, or other types of media suitable for storing electronic instructions. Specific implementation method three:

[0088] This embodiment is a high-resolution ultrasonic stress measurement device based on a sliding window. The device includes a processor and a memory. It should be understood that this includes any device with a processor and a memory described in this invention. The device may also include other units or modules that perform display, interaction, processing, control, and other functions through signals or instructions.

[0089] The memory stores at least one instruction, which is loaded and executed by the processor to implement the ultrasonic high-resolution stress measurement method based on a sliding window.

[0090] Those skilled in the art will understand that at least one stored instruction constitutes a computer program product corresponding to a method or system. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0091] This application is described with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products according to embodiments of this application, and can also be used with corresponding devices. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0092] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0093] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0094] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0095] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A high-resolution ultrasonic stress measurement method based on a sliding window, characterized in that, include: S1. Obtain stress measurements at one measuring point using small and large ultrasonic probes. and ; obtained and It was obtained in the following way: Marking lines are made on the surface of the component to discretize the measurement path into N tiny regions, with a spacing Δ. Two ultrasonic probes with a size difference of Δ are used to move along the marking lines in steps of Δ. The stress measurements at a single measuring point using the small and large ultrasonic probes are recorded as follows: and ; S2. Subtract the stress values ​​measured at n-1 locations with large and small probes at the same starting position to obtain the stress in multiple micro-regions. , as initial conditions; Using the initial conditions as known quantities, the stress value of each micro-region is calculated based on the stress and relationship of different micro-regions.

2. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 1, characterized in that, The stress in the small region of the initial conditions in step S2 , .

3. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 2, characterized in that, In step S2, the stress values ​​measured at n-1 locations with large and small probes at the same starting position are subtracted to obtain the stress in multiple micro-regions. The process includes: Subtract the equations for the large and small probes that correspond to the same starting position: ， The left side is simplified to obtain ; The same method is used to directly obtain n-1 stress values: .

4. A high-resolution ultrasonic stress measurement method based on a sliding window according to any one of claims 1 to 3, characterized in that, The stress and relationship of each micro-region are calculated based on the stress and relationship of different micro-regions. , , This represents the sum of the sliding stresses within the sliding window corresponding to positions i and i+1. This represents the stress value of the first tiny region of the sliding window corresponding to the i-th position. This represents the stress value of the last tiny region of the sliding window corresponding to the (i+1)th position.

5. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 4, characterized in that, The process of calculating the stress value of each micro-region based on the stress and relationship of different micro-regions, using the initial conditions as known quantities, includes: First, use large and small probe differences to indicate The movement difference of the large probe is used to represent it. By taking the initial conditions as known quantities, the stress value of the small region that can be calculated using the known quantities is obtained based on the stress and relationship of the small region. Then, using the calculated stress value of the micro-region as a known quantity, the stress difference of the micro-region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. This allows us to obtain the stress value for each tiny region.

6. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 5, characterized in that, The stress difference in a small region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. , M represents the number of positions that the large-size probe can effectively measure.

7. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 6, characterized in that, The stress difference in the micro-region is obtained based on the stress at the (i+1)th measurement position and the ith measurement position of the large-size probe. The process includes: First, the theoretical measurement equation for the large-size probe is determined: the large-size probe measures the stress in each region along the marked line, with the same step size as the small-size probe. It is assumed that the large-size probe can measure n tiny regions at one measurement point; the measured value at the i-th measurement point is denoted as... ; Then, for large-size probes, subtract the (i+1)th equation from the ith equation: ， The left side is simplified to Furthermore, the stress at the (i+1)th measurement position and the i-th measurement position of the large-size probe yields the stress difference in a small region.

8. The ultrasonic high-resolution stress measurement method based on a sliding window according to claim 7, characterized in that, During the measurement process of moving along the marked line with a step size of Δ using two ultrasonic probes of different sizes with a size difference of Δ, only the smaller probe is used to measure n-1 positions.

9. A computer storage medium, characterized in that, The storage medium stores at least one instruction, which is loaded and executed by a processor to implement the ultrasonic high-resolution stress measurement method based on a sliding window as described in any one of claims 1 to 8.

10. A high-resolution ultrasonic stress measurement device based on a sliding window, characterized in that, The device includes a processor and a memory, the memory storing at least one instruction, which is loaded and executed by the processor to implement the ultrasonic high-resolution stress measurement method based on a sliding window as described in any one of claims 1 to 8.

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