Modal force hammer dynamic test modal parameter error calibration method

Abstract

The application discloses a modal force hammer dynamics test modal parameter error calibration method, relates to the technical field of error calibration, and comprises the following steps: obtaining a collision angle interval based on a pendulum hammer type calibration device; obtaining a collision correlation surface of the collision angle interval by using a multi-impact analysis method; and performing error calibration on obtained modal parameters based on the collision correlation surface and a release angle of a modal force hammer. The application is used to solve the problem that, in the existing modal force hammer dynamics test modal parameter error calibration method, the rebound buffer after pendulum hammer impact cannot be accurately controlled for a soft rubber hammer head, impact data is discrete in multiple calibrations, the modal parameters of the rubber hammer head after pendulum hammer impact cannot be effectively obtained, and thus the calibration precision is affected and the parameter calibration error is increased.

Description

Technical Field

[0001] This invention relates to the field of error calibration technology, specifically to a method for calibrating the error of modal parameters in modal force hammer dynamics testing. Background Technology

[0002] Modal hammer dynamics testing is a portable structural modal analysis method. Its core is to apply controllable impact excitation to the structure under test using a modal hammer, and by collecting impact signals and structural vibration responses, identify core modal parameters such as the structure's natural frequency, damping ratio, and mode shape, and then analyze the structure's dynamic characteristics. Its core modal parameters mainly include natural frequency, damping ratio, mode shape, modal mass, modal stiffness, and modal damping.

[0003] Existing methods for calibrating modal parameter errors in modal hammer dynamics testing typically involve controlling the force magnitude and impact direction of the modal hammer during mechanical testing, and using laser irradiation points to achieve precise impact. This aims to improve the accuracy of the acquired signals and allow for repeated calibration. While this improved method achieves repeatability after the modal parameters are acquired, it suffers from several drawbacks. For soft rubber hammers, the rebound buffer after pendulum impact cannot be precisely controlled. Even with controlled force and direction for precise impact, impact data dispersion still exists in multiple calibrations, making it difficult to effectively acquire the modal parameters of the rubber hammer after pendulum impact. This affects calibration accuracy and increases parameter calibration error, as illustrated in patent application CN119959059A. A machine vision-based absolute modal force hammer calibration device and method are disclosed. This scheme improves the controllability of the force hammer's magnitude and direction, and enhances calibration repeatability and accuracy by proposing a vision alignment module, a pneumatic propulsion module, a laser absolute method measurement module, and a data acquisition module. Other improvements to modal parameter error calibration methods for modal force hammer dynamics testing typically focus on the consistency of conditions in repeated tests. However, they still cannot solve the problem of inaccurate control of the rebound buffer after pendulum impact for soft rubber hammers. This leads to discrete impact data in multiple calibrations, making it impossible to effectively obtain the modal parameters of the rubber hammer after pendulum impact, thus affecting calibration accuracy and increasing parameter calibration error. Therefore, it is necessary to improve the existing modal parameter error calibration methods for modal force hammer dynamics testing. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in the prior art by proposing a method for calibrating the modal parameter error in modal hammer dynamics testing. This method addresses the issue that existing methods for calibrating the modal parameter error in modal hammer dynamics testing cannot accurately control the rebound buffer after a pendulum impact on a soft rubber hammer head. This results in discrete impact data during multiple calibrations, making it impossible to effectively obtain the modal parameters of the rubber hammer head after the pendulum impact, thus affecting calibration accuracy and increasing parameter calibration error.

[0005] To achieve the above objectives, this application provides a method for calibrating the error of modal parameters in modal force hammer dynamic testing, comprising the following steps:

[0006] Based on the pendulum calibration device, the impact release angle before the hammer impacts the structure under test is obtained, and the impact release range obtained from the impact release angle is analyzed. Based on the analysis results, multiple impact angle ranges are obtained.

[0007] Based on the hammer head compression, contact time, and natural frequency when the hammer impacts the test result, the multi-impact analysis method is used to analyze each impact angle interval, and the impact-related surface corresponding to each impact angle interval is obtained based on the analysis results.

[0008] When using a modal hammer to perform dynamic testing on the structure under test, the obtained modal parameters are calibrated for error based on the impact-related surface and the release angle of the modal hammer.

[0009] Furthermore, based on the pendulum-type calibration device, the impact release angle before the hammer impacts the structure under test is obtained, and the impact release range obtained from the impact release angle is analyzed. Based on the analysis results, multiple impact angle ranges are obtained, including:

[0010] Based on the pendulum calibration device, the structure under test is placed vertically downward in the test space, and the angle formed between the hammer handle and the structure under test is recorded as the impact release angle. Based on the calibration standard of the pendulum calibration device, the maximum impact release angle that the hammer can be placed before impacting the structure under test is obtained and recorded as α. (0°, α] is recorded as the impact release range.

[0011] k values ​​are uniformly obtained in (0°, α], and are denoted in ascending order as available impact angles KZ1 to KZ. k Among them, the available impact angles are KZ1 to KZ. k The difference between any two adjacent available impact angles is the same;

[0012] Let h be the value of α divided by k and rounded up.

[0013] Furthermore, the impact release range obtained from the impact release angle is analyzed, and multiple impact angle ranges are obtained based on the analysis results, including:

[0014] For any available impact angle KZ t The hammer and the structure under test are subjected to h impact tests. Based on machine vision, the number of impacts obtained from the h impact images in the h impact tests are recorded as impact number CZ1 to impact number CZ. h The value obtained by rounding up the average of all test impacts is recorded as the usable impact angle KZ. t The interval parameter;

[0015] Impact testing includes adjusting the angle between the hammer handle and the structure under test to a usable impact angle KZ. t Afterwards, the hammer is released and a camera is used to capture images of the hammer impacting the structure under test after release. These images are recorded as test impact images, where t is a positive integer less than or equal to k and greater than or equal to 1. The test impact images are analyzed based on machine vision, and the number of times the hammer impacts the structure under test in the test impact images is recorded as the number of test impacts.

[0016] Furthermore, the impact release range obtained from the impact release angle is analyzed, and multiple impact angle ranges are obtained based on the analysis results, including:

[0017] Obtain the interval parameters corresponding to all available impact angles; for any interval parameter, the closed interval formed by the minimum and maximum values ​​among all available impact angles corresponding to the interval parameter is denoted as the impact angle interval of the interval parameter.

[0018] Get the collision angle intervals corresponding to all interval parameters.

[0019] Furthermore, multi-impact analysis includes:

[0020] For any available impact angle KZ in any impact angle interval β t h impact tests were performed on the hammer and the structure under test. The average value of all hammer head compression, the average value of all contact times, and the average value of all natural frequencies obtained from the h impact tests were denoted as the usable impact angle KZ. t The average compression, average time, and average frequency; the available impact angle KZ t The average compression, average time, and average frequency are stored in the impact database, which stores parameters in mm, ms, and Hz.

[0021] Impact testing includes adjusting the angle between the hammer handle and the structure under test to a usable impact angle KZ. tRelease the hammer and use a camera to capture images of the process from the first contact between the hammer and the structure under test to the first separation, and record these images as test impact images; record the time of the test impact images as the contact time.

[0022] Furthermore, the impact test also includes:

[0023] In the test impact image, the plane in contact between the hammer head of the hammer and the structure under test is recorded as the impact plane. A vertical line of the impact plane is randomly obtained and recorded as the impact vertical line. The length of the impact vertical line coinciding with the hammer head is recorded as the hammer head compression value. The hammer head compression value corresponding to each frame in the test impact image is obtained.

[0024] The minimum value of hammer compression corresponding to all frames in the test impact image is recorded as the hammer compression amount.

[0025] Furthermore, the impact test also includes:

[0026] When the angle between the hammer handle and the structure being measured is adjusted to the usable impact angle KZ t Afterwards, when the hammer impacts the structure under test, the raw signals are acquired based on the force sensor and the vibration response sensor. The raw signals are then converted into a frequency response function based on a computer and modal analysis software. The raw signals are digital signals obtained by converting the excitation force signal of the hammer impact acquired by the force sensor and the vibration response signal of the structure under test after impact acquired by the vibration response sensor using a data acquisition card.

[0027] Computers are used to receive digital signals, and modal analysis software is used to convert digital signals into frequency response functions;

[0028] The cross-coordinate of the peak value in the frequency response function is labeled as the natural frequency.

[0029] Furthermore, multi-impact analysis also includes:

[0030] Establish a spatial coordinate system, denoted as the impact-related coordinate system, where the units of the X-axis, Y-axis, and Z-axis are mm, ms, and Hz, respectively; obtain an impact database containing the average compression, average time, and average frequency of all available impact angles within the impact angle interval β, and for any available impact angle KZ recorded in the impact database... t The available impact angles KZ are respectively t The average compression, average time, and average frequency are used as the x-axis, y-axis, and y-axis, respectively. These values ​​are then plotted in the impact-related coordinate system and denoted as the available impact angle KZ. t The collision correlation point;

[0031] Obtain all available impact angles in the impact-related coordinate system within the impact angle interval β, and denote the surface obtained by fitting all impact-related points as the impact-related surface of the impact angle interval β.

[0032] The average compression, average time, and average frequency of all available impact angles in all impact angle intervals are obtained based on impact testing, and the impact-related surfaces corresponding to all impact angle intervals are obtained based on the impact-related coordinate system.

[0033] Furthermore, when using a modal hammer to perform dynamic testing on the structure under test, the error calibration of the obtained modal parameters based on the impact-related surface and the release angle of the modal hammer includes:

[0034] Obtain the impact correlation surfaces of all material modal force hammers and all impact angle intervals corresponding to the test structure of all materials;

[0035] When using a modal hammer to perform dynamic testing on the structure under test, based on the material of the modal hammer and the material of the structure under test, all corresponding impact angle intervals are obtained and recorded as candidate associated intervals.

[0036] Before the impact of the hammer on the structure under test during the dynamic test, the angle formed between the hammer handle and the structure under test is recorded as the real-time impact angle. The candidate correlation interval where the real-time impact angle is located is recorded as the available correlation interval, and the impact correlation surface of the available correlation interval is recorded as the parameter calibration surface.

[0037] Furthermore, when using a modal hammer to perform dynamic testing on the structure under test, the error calibration of the obtained modal parameters based on the impact-related surface and the release angle of the modal hammer also includes:

[0038] During the dynamic testing process, the contact time, hammer head compression, and natural frequency corresponding to the impact between the hammer and the structure under test are obtained based on the impact test, and are respectively recorded as test contact time, test compression, and test frequency.

[0039] In the impact-related coordinate system, the test contact time, test compression amount, and test frequency are respectively marked as the x-axis, y-axis, and d-axis, and recorded as test points; when the test points are within the parameter calibration surface, no parameter calibration is performed;

[0040] When the test point is not within the parameter calibration surface, the point with the smallest distance from the test point in the parameter calibration surface is recorded as the calibration point, and the ordinate of the calibration point is marked as the calibrated natural frequency.

[0041] The beneficial effects of this invention are as follows: This application first uses a pendulum-type calibration device to obtain the impact release angle of the hammer before it impacts the structure under test, and then analyzes the impact release interval obtained from the impact release angle. Based on the analysis results, multiple impact angle intervals are obtained. The advantage of this is that, when the pendulum-type hammer impacts the structure under test, the deformation of the rubber hammer head during impact is affected by the angle formed between the hammer handle and the structure under test. Therefore, by analyzing the impact release angle and obtaining multiple impact angle intervals, the impact release angles in different impact angle intervals can be analyzed separately in subsequent analysis, and the corresponding impact-related surfaces can be obtained. This helps to improve the accuracy of parameter calibration by obtaining the corresponding impact angle intervals after obtaining the real-time release angle of the modal hammer, thereby avoiding the problem that the standard for parameter calibration is greatly affected by the rebound buffer after the pendulum impact, and thus cannot achieve accurate calibration.

[0042] This application also uses a multi-impact analysis method to analyze each impact angle interval based on the hammer head compression, contact time, and natural frequency when the hammer impacts the test results, and obtains the impact correlation surface corresponding to each impact angle interval based on the analysis results. Finally, when using a modal hammer to perform dynamic testing on the structure under test, the obtained modal parameters are calibrated based on the impact correlation surface and the release angle of the modal hammer. The advantage of this is that by obtaining the impact correlation surface of each impact angle interval and calibrating the modal parameters based on the impact correlation surface, it can ensure that the deformation of the rubber hammer head corresponding to the standard for calibrating the parameters is close to the deformation of the rubber hammer head during actual impact, so as to achieve the purpose of accurate calibration of the obtained parameters. This avoids the problem that when using a rubber hammer head for pendulum impact, the impact data is discrete, which makes it impossible to accurately obtain the modal parameters that need to be calibrated from the discrete data, thus affecting the calibration accuracy and increasing the calibration error. Attached Figure Description

[0043] Figure 1 This is a flowchart of the steps of the method of the present invention;

[0044] Figure 2 This is a schematic diagram of the modal force hammer and the structure under test according to the present invention;

[0045] Figure 3 This is a schematic diagram showing the hammer head of the hammer of the present invention in contact with the structure being tested.

[0046] Figure 4 This is a schematic diagram of the electronic device of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1, please refer to Figure 1 As shown, this application provides a method for calibrating the error of modal parameters in modal force hammer dynamic testing, comprising the following steps:

[0049] Step S1: Based on the pendulum calibration device, obtain the impact release angle before the hammer impacts the structure under test, and analyze the impact release range obtained from the impact release angle. Based on the analysis results, obtain multiple impact angle ranges.

[0050] Step S1 includes: Step S101, based on the pendulum calibration device, the structure under test is placed vertically downward in the space to be tested, and the angle formed between the hammer handle of the hammer and the structure under test is recorded as the impact release angle; based on the calibration standard of the pendulum calibration device, the maximum impact release angle that the hammer can be placed before impacting the structure under test is obtained and recorded as α; (0°, α] is recorded as the impact release range.

[0051] Step S102: Obtain k values ​​uniformly in (0°, α], and record them in ascending order as available impact angles KZ1 to KZ. k Among them, the available impact angles are KZ1 to KZ. k The difference between any two adjacent available impact angles is the same;

[0052] In specific implementation, for example, in the data analysis of a pendulum-type impact test on the structure under test using a modal force hammer with a rubber hammer head, the value of α is obtained as 90°, that is, the impact release interval is (0°, 90°). In this embodiment, the value of k is 9, that is, the difference between any two adjacent usable impact angles from usable impact angle KZ1 to usable impact angle KZ9 is 10°. In practical applications, the value of k can be determined according to the calibration requirements of parameter calibration. The greater the calibration requirements, the smaller the value of k can be, so that the length of the impact angle interval is smaller when dividing the impact angle interval in the subsequent process, thereby improving the accuracy of parameter calibration using the impact-related surface after obtaining the impact-related surface from the impact angle interval. In addition, through data calculation, it can be found that 90 divided by 9 and rounded up yields a value of 10, that is, h is 10.

[0053] In this embodiment, the purpose of repeating the impact test h times is to obtain the impact angle range of each available impact angle more accurately. If the value of k is larger, it means that the division of α is more detailed. If a larger h is still used at this time, it will lead to a longer overall data analysis time. Therefore, the value of h can be appropriately reduced at this time to ensure that the data acquisition time is reduced while obtaining the required impact range, thereby improving the data analysis efficiency. That is, in this embodiment, the value of k is negatively correlated with the value of h.

[0054] Step S103: Divide α by k and round up, and denote the value as h.

[0055] Step S1 further includes: Step S104, for any available impact angle KZ t The hammer and the structure under test are subjected to h impact tests. Based on machine vision, the number of impacts obtained from the h impact images in the h impact tests are recorded as impact number CZ1 to impact number CZ. h The value obtained by rounding up the average of all test impacts is recorded as the usable impact angle KZ. t The interval parameter;

[0056] Step S105, the impact test includes: adjusting the angle between the hammer handle and the structure under test to an acceptable impact angle KZ. t Afterwards, the hammer is released and a camera is used to capture images of the hammer impacting the structure under test after release. These images are recorded as test impact images, where t is a positive integer less than or equal to k and greater than or equal to 1. The test impact images are analyzed based on machine vision, and the number of times the hammer impacts the structure under test in the test impact images is recorded as the number of test impacts.

[0057] Step S1 further includes: Step S106, obtaining the interval parameters corresponding to all available impact angles; for any interval parameter, the closed interval formed by the minimum and maximum values ​​among all available impact angles corresponding to the interval parameter is recorded as the impact angle interval of the interval parameter.

[0058] In specific implementation, for example, during a data analysis, the interval parameters corresponding to all available impact angles are 3, 4, 5, and 6, respectively. Among them, the available impact angles corresponding to interval parameter 3 are 10° and 20°, respectively. Through analysis, it can be found that the impact angle interval corresponding to interval parameter 3 is [10°, 20°]. In addition, through data analysis, the impact angle intervals corresponding to 4, 5, and 6 are [30°, 40°], [50°, 60°], and [70°, 90°], respectively. By obtaining the impact angle intervals, in subsequent analysis, the impact release angles within different impact angle intervals can be analyzed separately, and the corresponding impact-related surfaces can be obtained. This helps to improve the accuracy of parameter calibration after obtaining the real-time release angle of the modal hammer by obtaining the corresponding impact angle intervals.

[0059] Step S107: Obtain the collision angle intervals corresponding to all interval parameters;

[0060] In the specific implementation process, for example, after the above analysis, the schematic diagram of the modal force hammer and the structure under test is as follows: Figure 2 As shown, CT is the rubber hammer head of the modal hammer, BC is the structure under test, and regions QJ1 to QJ4 are the regions where the impact angle intervals corresponding to interval parameters 3, 4, 5 and 6 are located. For example, when the modal hammer is fixed in region QJ2 before impact, the corresponding impact angle interval is [30°, 40°].

[0061] Step S2: Based on the hammer head compression, contact time and natural frequency when the hammer impacts the test result, the multi-impact analysis method is used to analyze each impact angle interval, and the impact-related surface corresponding to each impact angle interval is obtained based on the analysis results.

[0062] The multi-impact analysis method includes: step S201, for any available impact angle KZ in any impact angle interval β. t h impact tests were performed on the hammer and the structure under test. The average value of all hammer head compression, the average value of all contact times, and the average value of all natural frequencies obtained from the h impact tests were denoted as the usable impact angle KZ. t The average compression, average time, and average frequency; the available impact angle KZ t The average compression, average time, and average frequency are stored in the impact database, which stores parameters in mm, ms, and Hz.

[0063] Step S202, the impact test includes: Step S2021, adjusting the angle between the hammer handle of the hammer and the structure under test to an usable impact angle KZ. tRelease the hammer and use a camera to capture images of the process from the first contact between the hammer and the structure under test to the first separation, and record these images as test impact images; record the time of the test impact images as the contact time.

[0064] Step S2022: In the test impact image, the plane in which the hammer head of the hammer contacts the structure under test is recorded as the impact plane. A vertical line of the impact plane is randomly obtained and recorded as the impact vertical line. The length of the impact vertical line coinciding with the hammer head is recorded as the hammer head compression value. The hammer head compression value corresponding to each frame in the test impact image is obtained.

[0065] Step S2023: Record the minimum value of hammer compression corresponding to all frames in the test impact image as the hammer compression amount;

[0066] In specific implementation processes, for example, during a data analysis, the state of the cross-section of the hammerhead when it contacts the structure being measured is as follows: Figure 3 As shown, analysis reveals that the plane containing the straight line CP is the impact plane, and the dashed line CC is the impact perpendicular line. Therefore, the hammer compression value at this time is L. By obtaining the contact time and hammer compression, and further obtaining the average value of the contact time and hammer compression for all available impact angles in the impact angle range, we can obtain the standard parameters corresponding to the contact time and rubber hammer compression of the hammer head and the tested structure at different available impact angles when the angle formed by the hammer handle and the tested structure is in different impact angle ranges. This allows for the accurate calibration of the parameters obtained from the dynamic test based on the impact correlation surface obtained after h impact tests for all available impact angles in the impact angle range during subsequent analysis.

[0067] The impact test also includes step S2024, when the angle between the hammer handle and the structure under test is adjusted to the usable impact angle KZ. t Afterwards, when the hammer impacts the structure under test, the raw signals are acquired based on the force sensor and the vibration response sensor. The raw signals are then converted into a frequency response function based on a computer and modal analysis software. The raw signals are digital signals obtained by converting the excitation force signal of the hammer impact acquired by the force sensor and the vibration response signal of the structure under test after impact acquired by the vibration response sensor using a data acquisition card.

[0068] Step S2025: The computer is used to receive the digital signal, and the modal analysis software is used to convert the digital signal into a frequency response function;

[0069] Step S2026: Mark the x-coordinate of the peak value in the frequency response function as the natural frequency;

[0070] In specific implementation, the acquisition of natural frequencies can be achieved by using equipment capable of acquiring natural frequencies. In the analysis of this embodiment, data acquisition and signal conversion are performed during the impact of the modal hammer using a force sensor, vibration response sensor, computer, and modal analysis software, thereby acquiring the natural frequencies. Through the analysis of this embodiment, when the available impact angle is 40°, the natural frequencies obtained from 10 impact tests are 500Hz, 501Hz, 502Hz, 498Hz, 499Hz, 500Hz, 500Hz, 500Hz, 500Hz, and 500Hz, respectively. Therefore, the average frequency at 40° is 500Hz.

[0071] The multi-impact analysis method also includes: step S203, establishing a spatial coordinate system, denoted as the impact-related coordinate system, wherein the units of the X-axis, Y-axis, and Z-axis of the impact-related coordinate system are mm, ms, and Hz, respectively; obtaining an impact database storing the average compression, average time, and average frequency of all available impact angles in the impact angle interval β, and for any available impact angle KZ recorded in the impact database... t The available impact angles KZ are respectively t The average compression, average time, and average frequency are used as the x-axis, y-axis, and y-axis, respectively. These values ​​are then plotted in the impact-related coordinate system and denoted as the available impact angle KZ. t The collision correlation point;

[0072] Step S204: Obtain all available impact angles in the impact-related coordinate system in the impact angle interval β, and denote the surface obtained by fitting all impact-related points as the impact-related surface of the impact angle interval β.

[0073] In the specific implementation process, by constructing an impact database and obtaining the impact-related surface corresponding to each impact angle interval in the spatial coordinate system, it can be ensured that the deformation of the rubber hammer corresponding to the standard for parameter calibration is close to the deformation of the rubber hammer during actual impact. That is, the parameters of each point in the impact-related surface are close to the parameters of the rubber hammer actually collected during impact, so as to achieve the purpose of accurate calibration of the acquired parameters. In this embodiment, the parameters related to the deformation of the rubber hammer are contact time and hammer compression.

[0074] Step S205: Based on the impact test, obtain the average compression, average time and average frequency of all available impact angles in all impact angle intervals, and obtain the impact-related surfaces corresponding to all impact angle intervals based on the impact-related coordinate system.

[0075] Step S3: When using a modal hammer to perform dynamic testing on the structure under test, the obtained modal parameters are calibrated for error based on the impact-related surface and the release angle of the modal hammer.

[0076] Step S3 includes: Step S301, obtaining the impact correlation surfaces of all material modal force hammers and all impact angle intervals corresponding to the test structure of all materials;

[0077] Step S302: When using a modal hammer to perform dynamic testing on the structure under test, based on the material of the modal hammer used for dynamic testing and the material of the structure under test, obtain all corresponding impact angle intervals and record them as candidate associated intervals.

[0078] Step S303: Before the impact of the hammer on the structure under test during the dynamic test, the angle formed between the hammer handle and the structure under test is recorded as the real-time impact angle. The candidate correlation interval where the real-time impact angle is located is recorded as the available correlation interval. The impact correlation surface of the available correlation interval is recorded as the parameter calibration surface.

[0079] Step S3 also includes: Step S304, during the dynamic test, the contact time, hammer head compression and natural frequency after the impact of the hammer and the structure under test are obtained based on the impact test, and are recorded as test contact time, test compression and test frequency respectively.

[0080] Step S305: In the impact-related coordinate system, mark points with test contact time, test compression amount, and test frequency as the horizontal, vertical, and vertical axes, respectively, and record them as test points; when the test points are within the parameter calibration surface, no parameter calibration is performed;

[0081] In this embodiment, for example, if the real-time impact angle is 40° during a data analysis, the available correlation interval should be [30°, 40°]. That is, after obtaining the test contact time, test compression, and test frequency, the parameter calibration is judged by obtaining the positional relationship between the test point and the impact correlation surface of [30°, 40°]. If the test point is outside the impact correlation surface, it indicates that there is an error in the natural frequency when the deformation of the rubber hammer remains unchanged, so the natural frequency needs to be calibrated.

[0082] Step S306: When the test point is not within the parameter calibration surface, the point with the smallest distance from the test point in the parameter calibration surface is recorded as the calibration point, and the ordinate of the calibration point is marked as the calibrated natural frequency.

[0083] Example 2, please refer to Figure 4 As shown, Figure 4A schematic diagram of an electronic device is provided, which may include a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory communicate with each other via the communication bus. The memory stores computer-readable instructions, and the processor can call these instructions. When the processor executes a computer-readable instruction, it performs steps similar to those in a modal hammer dynamic testing modal parameter error calibration method to achieve the following functions: First, based on a pendulum calibration device, the impact release angle of the hammer before impacting the structure under test is obtained, and the impact release interval obtained from the impact release angle is analyzed. Based on the analysis results, multiple impact angle intervals are obtained. Then, based on the hammer head compression, contact time, and natural frequency during the impact of the hammer on the test structure, a multi-impact analysis method is used to analyze each impact angle interval, and the impact correlation surface corresponding to each impact angle interval is obtained based on the analysis results. Finally, when using a modal hammer to perform dynamic testing on the structure under test, the obtained modal parameters are calibrated for error based on the impact correlation surface and the release angle of the modal hammer.

[0084] Furthermore, when the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] Example 3: This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute a modal hammer dynamic test modal parameter error calibration method provided by the above methods. The method includes: first, based on a pendulum calibration device, obtaining the impact release angle of the hammer before impacting the structure under test, and analyzing the impact release interval obtained from the impact release angle, and obtaining multiple impact angle intervals based on the analysis results; then, based on the hammer head compression, contact time, and natural frequency when the hammer impacts the test result, analyzing each impact angle interval using a multi-impact analysis method, and obtaining the impact correlation surface corresponding to each impact angle interval based on the analysis results; finally, when using a modal hammer to perform dynamic testing on the structure under test, calibrating the obtained modal parameters based on the impact correlation surface and the release angle of the modal hammer.

[0086] Example 4: This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it performs the steps of the above-described modal hammer dynamic test modal parameter error calibration method to achieve the following functions: First, based on the pendulum calibration device, the impact release angle before the hammer impacts the structure under test is obtained, and the impact release interval obtained from the impact release angle is analyzed. Based on the analysis results, multiple impact angle intervals are obtained. Then, based on the hammer head compression, contact time, and natural frequency when the hammer impacts the test result, a multi-impact analysis method is used to analyze each impact angle interval, and the impact correlation surface corresponding to each impact angle interval is obtained based on the analysis results. Finally, when the modal hammer is used to perform dynamic testing on the structure under test, the obtained modal parameters are calibrated based on the impact correlation surface and the release angle of the modal hammer.

[0087] Based on the above description of the embodiments, the embodiments of the present invention can be provided as methods, systems, or computer program products. Based on this understanding, the above technical solutions, in essence or in terms of their contribution to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or certain parts of the embodiments.

[0088] In the embodiments provided in this application, it should be understood that the disclosed system or method can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of modules or units is only a logical functional division, and there may be other division methods in actual implementation. Furthermore, multiple modules or units may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces. The indirect coupling or communication connection between systems, modules, and units may be electrical, mechanical, or other forms.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A modal force hammer dynamics test modal parameter error calibration method, characterized by, The method comprises the following steps: Based on the pendulum type calibration device, the impact release angle of the force hammer before impacting the measured structure is obtained, and the impact release interval obtained from the impact release angle is analyzed, and based on the analysis result, a plurality of impact angle intervals are obtained; Based on the hammer head compression amount, contact time and natural frequency of the force hammer when impacting the measured structure, the multi-impact analysis method is used to analyze each impact angle interval, and based on the analysis result, the impact correlation surface corresponding to each impact angle interval is obtained; When using a modal force hammer to perform a dynamic test on the measured structure, based on the impact correlation surface and the release angle of the modal force hammer, the obtained modal parameters are error calibrated; The multi-impact analysis method comprises: For any available impact angle KZ in any impact angle interval β t h impact tests were performed on the hammer and the structure under test. The average value of all hammer head compression, the average value of all contact times, and the average value of all natural frequencies obtained from the h impact tests were denoted as the usable impact angle KZ. t The average compression, average time, and average frequency; the available impact angle KZ t The average compression, average time, and average frequency are stored in the impact database, which stores parameters in mm, ms, and Hz. The impact test comprises: adjusting the included angle between the hammer handle of the force hammer and the measured structure to the available impact angle KZ t , releasing the force hammer, and using a camera to shoot the image corresponding to the process from the first contact of the released force hammer with the measured structure to the first separation, and recording the test impact image; recording the time of the test impact image as the contact time; In the test impact image, the plane where the hammer head of the force hammer contacts the measured structure is recorded as an impact plane, a vertical line of the impact plane is randomly obtained and recorded as an impact vertical line, and the length where the impact vertical line coincides with the hammer head is recorded as a hammer head compression value, and the hammer head compression value corresponding to each frame in the test impact image is obtained; The minimum value of the hammer head compression values corresponding to all frames in the test impact image is recorded as the hammer head compression amount; When the hammer handle of the force hammer and the angle formed by the measured structure are adjusted to the available impact angle KZ t After the force hammer is released to impact the measured structure, the original signals are acquired based on the force sensor and the vibration response sensor, and the original signals are converted into frequency response functions based on the computer and the modal analysis software, wherein the original signals are digital signals obtained by converting the excitation force signals when the force hammer impacts, which are collected by the force sensor, and the vibration response signals of the measured structure after being impacted, which are collected by the vibration response sensor, using the data acquisition card. The computer is used to receive the digital signal, and the modal analysis software is used to convert the digital signal into a frequency response function; The abscissa of the peak value in the frequency response function is recorded as the natural frequency; The multi-impact analysis method further comprises: A space coordinate system is established and recorded as an impact-related coordinate system, wherein the units of the X-axis, the Y-axis and the Z-axis of the impact-related coordinate system are mm, ms and Hz respectively; an impact database of the average compression, the average time and the average frequency of all available impact angles of the impact angle interval β is obtained, and for any one available impact angle KZ t of the impact database, the average compression, the average time and the average frequency of the available impact angle KZ t are taken as the abscissa, the ordinate and the vertical coordinate respectively, and the impact-related coordinate system is marked and recorded as the impact-related point of the available impact angle KZ t . Impact correlation points of all available impact angles in the impact angle interval β in the impact correlation coordinate system are obtained, and a surface fitted from all the impact correlation points is recorded as the impact correlation surface of the impact angle interval β; Based on the impact test, the average compression amount, the average time and the average frequency of all available impact angles in all impact angle intervals are obtained, and the impact correlation surface corresponding to all impact angle intervals is obtained based on the impact correlation coordinate system.

2. The modal force hammer dynamics test modal parameter error calibration method of claim 1, wherein, Based on the pendulum type calibration device, the impact release angle of the force hammer before impacting the measured structure is obtained, and the impact release interval obtained from the impact release angle is analyzed, and based on the analysis result, a plurality of impact angle intervals are obtained, which comprises: Based on the pendulum type calibration device, the measured structure is placed vertically downward in the space to be tested, and the included angle formed by the handle of the force hammer and the measured structure is recorded as the impact release angle; based on the calibration standard of the pendulum type calibration device, the maximum impact release angle allowed to be placed before the force hammer impacts the measured structure is obtained and recorded as α; (0°, α] is recorded as the impact release interval; In (0°, a], k values are uniformly obtained, and are sequentially recorded as available impact angles KZ1 to available impact angles KZk from small to large k wherein, the difference between any two adjacent available impact angles KZ1 to available impact angles KZk is the same k ​ The value obtained by dividing α by k and taking the upper integer is recorded as h.

3. The modal force hammer dynamics test modal parameter error calibration method of claim 2, wherein, The analysis of the impact release interval obtained from the impact release angle based on the analysis result to obtain a plurality of impact angle intervals further comprises: For any one available impact angle KZ t : h times of impact tests are performed on the force hammer and the measured structure, and based on mechanical vision, the test impact times obtained from h test impact images in the h times of impact tests are sequentially recorded as test impact time CZ1 to test impact time CZ h ; the value obtained by rounding up the average of all test impact times is recorded as the interval parameter of the available impact angle KZ t . The impact test comprises: adjusting the included angle between the hammer handle of the force hammer and the measured structure to the available impact angle KZ t Afterwards, the force hammer is released and a camera is used to take an image of the impact of the force hammer with the measured structure after the force hammer is released, recorded as a test impact image, wherein t is a positive integer less than or equal to k and greater than or equal to 1; the test impact image is analyzed based on mechanical vision, and the number of times of impact of the force hammer with the measured structure in the test impact image is recorded as a test impact number.

4. The modal force hammer dynamics test modal parameter error calibration method of claim 3, wherein, The analysis of the impact release interval obtained from the impact release angle based on the analysis result to obtain a plurality of impact angle intervals further comprises: Interval parameters corresponding to all available impact angles are obtained; for any interval parameter, a closed interval formed by the minimum value and the maximum value of all available impact angles corresponding to the interval parameter is recorded as the impact angle interval of the interval parameter; The impact angle intervals corresponding to all interval parameters are obtained.

5. The modal force hammer dynamics test modal parameter error calibration method of claim 4, wherein, When using a modal force hammer to perform a dynamic test on the measured structure, based on the impact correlation surface and the release angle of the modal force hammer, the obtained modal parameters are error calibrated, which comprises: Obtain the impact correlation surface of all the material modal hammers and all the impact angle intervals of the measured structure corresponding to all the materials; When the modal hammer is used to test the dynamics of the measured structure, based on the material of the modal hammer used to test the dynamics and the material of the measured structure, all the impact angle intervals corresponding to them are obtained, and all the impact angle intervals are recorded as the selected correlation intervals; Before the hammer and the measured structure are impacted during the dynamics test, the angle formed by the hammer handle and the measured structure is recorded as the real-time impact angle, and the selected correlation interval in which the real-time impact angle is located is recorded as the available correlation interval, and the impact correlation surface of the available correlation interval is recorded as the parameter correction surface.

6. The modal force hammer dynamics test modal parameter error calibration method of claim 5, wherein, When the modal hammer is used to test the dynamics of the measured structure, based on the impact correlation surface and the release angle of the modal hammer, the error calibration of the obtained modal parameters further includes: During the dynamics test, based on the impact test, the contact time, the hammer head compression amount and the natural frequency corresponding to the impact of the hammer and the measured structure are obtained, and are recorded as the test contact time, the test compression amount and the test frequency respectively; In the impact correlation coordinate system, the test contact time, the test compression amount and the test frequency are respectively taken as the horizontal coordinate, the vertical coordinate and the vertical coordinate to mark the points, and the test points are recorded; when the test point is in the parameter correction surface, no parameter calibration is performed; When the test point is not in the parameter correction surface, the point in the parameter correction surface closest to the test point is recorded as the calibration point, and the vertical coordinate of the calibration point is recorded as the calibrated natural frequency.

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