Modal test method and system based on environment control

Abstract

The invention relates to the technical field of modal tests, and discloses a modal test method and system based on environment control, and the system comprises an environment simulation module which is configured to set environment scene parameters according to experiment requirements; the test platform module is configured to limit and fix the tested structural member; the excitation module is configured to switch excitation modes according to the environment scene parameters and the structural characteristics of the tested structural component and excite the tested structural component; the data acquisition module is configured to acquire test data of the tested structural member; the data processing module is configured to pre-process the test data and perform modal analysis based on the pre-processed test data; and the evaluation module is configured to visually display the modal analysis result and perform structure evaluation based on the modal analysis result. According to the invention, the modal test automation and intelligence of the tested structural member in various environment scenes are realized.

Description

Technical Field

[0001] This invention relates to the field of modal testing technology, and in particular to a modal testing method and system based on environmental control. Background Technology

[0002] Modal testing is a crucial method for studying the dynamic characteristics of structures. By measuring the vibration response of a structure, modal parameters such as natural frequencies, mode shapes, and damping ratios can be identified. However, in practical engineering, many structures are subjected to complex and variable environmental factors during service, which significantly alter their dynamic characteristics. Traditional modal testing methods are typically conducted in ideal laboratory environments, failing to accurately reflect the modal characteristics of structures under actual environmental conditions, leading to significant discrepancies between test results and practical applications. Therefore, there is an urgent need for a modal testing method that can consider environmental factors to improve the accuracy and reliability of test results, providing stronger support for structural design, optimization, and health monitoring. Summary of the Invention

[0003] The purpose of this invention is to provide a modal testing system and method based on environmental control, which solves the problem that traditional modal testing methods are usually carried out in an ideal laboratory environment, which cannot accurately reflect the modal characteristics of the structure under actual environmental conditions, resulting in a large deviation between the test results and actual applications.

[0004] This invention provides a modal testing system based on environmental control, comprising:

[0005] The environment simulation module is configured to set environmental scenario parameters according to experimental requirements;

[0006] The test platform module is configured to limit and fix the structural component under test;

[0007] The excitation module is configured to switch the excitation mode according to the environmental scene parameters and the structural characteristics of the structure under test, and to excite the structure under test.

[0008] The data acquisition module is configured to acquire test data of the structure under test;

[0009] The data processing module is configured to preprocess the experimental data and perform modal analysis based on the preprocessed experimental data;

[0010] The evaluation module is configured to visualize the modal analysis results and perform structural evaluation based on the modal analysis results.

[0011] Preferably, the environmental scene parameters include the temperature range, humidity range, air pressure conditions, and airflow speed of the environment.

[0012] Preferably, the environmental simulation module includes: a temperature control unit for setting a temperature range using a heater and a cooler;

[0013] Humidity control unit, used to set humidity range using humidifiers and dehumidifiers;

[0014] A pressure regulation unit is used to simulate air pressure conditions at different altitudes;

[0015] The airflow control unit is used to set the airflow speed using an airflow speed generator.

[0016] Preferably, the test platform module includes a fixture, a three-dimensional guide rail, and a mounting platform. The fixture is disposed on the mounting platform and is used to hold the structural component under test. The three-dimensional guide rail is disposed on the mounting platform and is used to control the three-dimensional position of the excitation module.

[0017] Preferably, the excitation module includes: an electromagnetic exciter for providing periodic excitation force;

[0018] Impact hammer, used to provide striking excitation;

[0019] Acoustic exciter, used to provide acoustic load excitation.

[0020] Preferably, the data acquisition module includes several types of sensors, including acceleration sensors, displacement sensors, strain sensors, and pressure sensors. The test data of the tested structural component acquired by the data acquisition module through the sensors includes vibration response data, deformation data, and force data.

[0021] Preferably, when the data processing module preprocesses the test data, the preprocessing includes noise reduction, filtering, and normalization.

[0022] Preferably, the data processing module performs modal analysis based on the preprocessed experimental data, including:

[0023] Based on the structural characteristics of the tested structural component, the modal analysis algorithm is determined.

[0024] A structural modal identification model based on environmental factors is established, and the model is iteratively calculated and corrected.

[0025] Modal analysis was performed based on the modified structural modal identification model and preprocessed experimental data.

[0026] Preferably, the evaluation module visualizes the modal analysis results and performs structural evaluation based on the modal analysis results, including:

[0027] The modal analysis results can be visualized in the form of graphs, charts, or animations.

[0028] Establish a database for evaluating test results, compare and analyze the modal analysis results under current environmental conditions with those under standard environmental conditions or historical test data conditions, and evaluate the stability and reliability of the tested structural components.

[0029] This invention also discloses an environmentally controlled modal testing method, applied to the aforementioned environmentally controlled modal testing system, comprising:

[0030] Limit and fix the structural component under test;

[0031] Set environmental scene parameters according to experimental requirements, set excitation mode according to environmental scene parameters and structural characteristics of the tested structure, and excite the tested structure.

[0032] Acquire test data of the tested structural component, preprocess the test data, and perform modal analysis based on the preprocessed test data;

[0033] The modal analysis results are visualized, and structural evaluation is performed based on the modal analysis results.

[0034] Compared with existing technologies, the advantages of this invention are that it can simulate the complex environmental conditions of structures during actual service, making the modal test results closer to reality, improving the accuracy and reliability of the test results, and providing stronger support for the design, evaluation, and maintenance of structures. Through the combination and adaptive selection of multiple excitation methods, as well as optimized sensor layout and data acquisition system, the modal characteristics of the structure can be comprehensively and effectively excited and measured, ensuring the integrity and accuracy of modal parameter identification. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 This is a functional block diagram of a modal testing system based on environmental control according to the present invention;

[0037] Figure 2 This is a flowchart of a modal testing method based on environmental control according to the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0039] like Figure 1 As shown, the present invention provides a modal testing system based on environmental control, comprising:

[0040] The environment simulation module is configured to set environmental scenario parameters according to experimental requirements;

[0041] The test platform module is configured to limit and fix the structural component under test;

[0042] The excitation module is configured to switch the excitation mode according to the environmental scene parameters and the structural characteristics of the structure under test, and to excite the structure under test.

[0043] The data acquisition module is configured to acquire test data of the structure under test;

[0044] The data processing module is configured to preprocess the experimental data and perform modal analysis based on the preprocessed experimental data;

[0045] The evaluation module is configured to visualize the modal analysis results and perform structural evaluation based on the modal analysis results.

[0046] This invention achieves automated and intelligent modal testing of structural components under various environmental scenarios by integrating modules for environmental simulation, testing platform, excitation, data acquisition, data processing, and evaluation. The environmental simulation module ensures consistency of test conditions and improves the reliability of test results; the testing platform module guarantees the stability of the structural components during testing and reduces external interference; the excitation module flexibly switches excitation modes according to the characteristics of the structural components, effectively stimulating their modal responses; the data acquisition module efficiently and accurately captures test data, providing a solid foundation for subsequent analysis; the data processing module performs rapid preprocessing and modal analysis on massive amounts of test data, significantly improving analysis efficiency; and the evaluation module presents complex modal analysis results in an intuitive form, facilitating user understanding and application, while the structural evaluation based on the analysis results provides a scientific basis for structural optimization design. In summary, this invention significantly improves the efficiency and accuracy of modal testing, promoting technological progress in the field of structural dynamics.

[0047] In some embodiments of this application, the environmental scene parameters include the temperature range, humidity range, air pressure conditions, and airflow speed of the environment.

[0048] In some embodiments of this application, the environmental simulation module includes: a temperature control unit for setting a temperature range using a heater and a cooler; a humidity control unit for setting a humidity range using a humidifier and a dehumidifier; an air pressure regulation unit for simulating air pressure conditions at different altitudes; and an airflow control unit for setting an airflow speed using an airflow speed generator.

[0049] In this embodiment, the environmental simulation module enables precise control of various environmental parameters such as temperature, humidity, air pressure, and airflow velocity. The temperature control unit utilizes a heater and a cooler to precisely adjust the set temperature range; the humidity control unit employs a humidifier and a dehumidifier, combined with humidity sensor feedback, to maintain a stable humidity environment; the air pressure regulation device can simulate air pressure conditions at different altitudes or within pressure vessels; and the airflow velocity generator can produce controllable, uniform airflow to simulate environmental factors such as wind load. Based on experimental requirements, different combinations of environmental scenario parameters can be pre-set in the control system, such as high temperature and high humidity, low temperature and low pressure, and steady-state airflow conditions. The environmental simulation module can quickly and accurately switch between and stably maintain these environmental scenarios.

[0050] In some embodiments of this application, the test platform module includes a fixture, a three-dimensional guide rail, and a mounting platform. The fixture is disposed on the mounting platform and is used to hold the structural component under test. The three-dimensional guide rail is disposed on the mounting platform and is used to control the three-dimensional position of the excitation module.

[0051] In this embodiment, a universal fixture adaptable to different structural types can be used to ensure the fixation and positioning accuracy of the tested structural component during environmental simulation, reducing modal characteristic changes caused by installation errors. The fixture is designed with low-mass, high-rigidity materials to minimize the impact on the dynamic characteristics of the structure. The tested structural component is securely mounted on the mounting platform using the universal fixture. Tools such as a laser rangefinder and a level are used to precisely adjust the position and orientation of the structure to ensure that the installation accuracy meets the test requirements.

[0052] In this embodiment, the main body of the fixture is made of carbon fiber reinforced polymer (CFRP). Carbon fiber has extremely high strength and stiffness, far exceeding that of ordinary metal materials, while its mass density is low, only about one-quarter that of steel, effectively reducing the influence of the fixture's own mass on the modal characteristics of the test structure. Furthermore, carbon fiber composites have good corrosion resistance and fatigue resistance, adapting to various complex environmental simulation test conditions. For the clamping components that directly contact the structure under test, a titanium alloy with a hard alloy coating is used. Titanium alloys are characterized by high strength and low density. The hard alloy coating increases the surface hardness and wear resistance of the clamping components, ensuring that the surface of the structure is not damaged by friction when clamping the test structure, while also ensuring the stability and uniformity of the clamping force.

[0053] In this embodiment, the fixture adopts a modular design concept, consisting of a basic clamping block, adjustable clamping arms, and positioning pins. The basic clamping block is cuboid in shape with a honeycomb-like reinforcing structure inside to improve its resistance to deformation. The adjustable clamping arms are connected to the basic clamping block via a high-precision threaded knob. The threaded knob uses a fine-pitch thread design, enabling minute adjustments to the clamping arm position, thereby precisely controlling the clamping force. On the inner side of the clamping arms, an arc-shaped groove matching the shape of the test structure is machined. A flexible buffer pad made of silicone rubber is embedded in the groove, which not only protects the surface of the test structure from scratches but also compensates for dimensional tolerances between the clamping arms and the structure to a certain extent, ensuring a uniform distribution of clamping force. Positioning pins are distributed around the basic clamping block and are used to engage with positioning holes on the mounting platform to achieve precise positioning of the fixture on the mounting platform. The diameter and positional accuracy of the positioning pins are precision machined, with tolerances controlled within a very small range to ensure the repeatability of the fixture's positioning accuracy.

[0054] In some embodiments of this application, the excitation module includes: an electromagnetic exciter for providing periodic excitation force; an impact hammer for providing striking excitation; and an acoustic exciter for providing acoustic load excitation.

[0055] In this embodiment, an excitation module combining multiple excitation methods is used, including an electromagnetic exciter, an impact hammer, and an acoustic exciter. The appropriate excitation method and parameters can be automatically selected based on current environmental conditions and structural characteristics. For example, in low-temperature environments, due to changes in material properties, an impact hammer may be preferentially selected for transient excitation to avoid performance instability issues caused by low temperatures in the electromagnetic exciter.

[0056] In this embodiment, for the electromagnetic exciter, the frequency range, amplitude, and waveform type (such as sine wave, sweep signal, etc.) of the excitation signal are set to precisely control the movement of the exciter, enabling it to apply excitation force to the test structure at a predetermined position. Simultaneously, a force sensor is used to monitor the magnitude and direction of the excitation force in real time, ensuring the accuracy and stability of the excitation. When using an impact hammer, the operator excites the tested structure by striking it according to the predetermined striking position and force requirements. The impact hammer is equipped with a force sensor, which can measure the magnitude and duration of the striking force in real time and transmit the data to the data acquisition system. If an acoustic exciter is used, the frequency, amplitude, and propagation direction of the acoustic waves are adjusted according to the acoustic characteristics of the structure and the test requirements, so that the acoustic waves act uniformly on the surface of the test structure, exciting the acoustic vibration modes of the structure.

[0057] In some embodiments of this application, the data acquisition module includes several types of sensors, including acceleration sensors, displacement sensors, strain sensors and pressure sensors. The test data of the tested structural component acquired by the data acquisition module through the sensors includes vibration response data, deformation data and force data.

[0058] In this embodiment, sensors are strategically arranged on the structure under test. Accelerometers measure the vibration acceleration response of the structure, displacement sensors measure the displacement changes of the structure, strain sensors monitor the strain distribution of the structure, and pressure sensors measure the air pressure or hydraulic load (if any) on the structure surface. The sensor placement is optimized based on the modal analysis and finite element simulation results of the structure to ensure accurate capture of the structure's dynamic response.

[0059] A high-speed, stable data acquisition system is established, capable of simultaneously acquiring signals from multiple sensors, and possessing anti-interference and filtering functions to ensure data accuracy and reliability. The acquired data is transmitted in real-time to the data processing module via a high-speed data transmission line, while simultaneously being buffered locally to prevent data loss or errors during transmission.

[0060] In some embodiments of this application, when the data processing module preprocesses the test data, the preprocessing includes noise reduction, filtering, and normalization.

[0061] In some embodiments of this application, the data processing module performs modal analysis based on preprocessed test data, including: determining a modal analysis algorithm based on the structural characteristics of the tested structural component; establishing a structural modal identification model based on environmental factors, and iteratively calculating and correcting the structural modal identification model; and performing modal analysis based on the corrected structural modal identification model and the preprocessed test data.

[0062] In this embodiment, the experimental data is preprocessed. First, a digital filter is used to remove high-frequency noise and interference components from the signal, such as power frequency interference and electromagnetic interference. Then, the data is normalized to make the data from different sensors comparable, which facilitates subsequent modal analysis.

[0063] In this embodiment, a suitable modal analysis algorithm is selected based on the characteristics of the structure under test and the environmental conditions. For linear structures, frequency domain methods (such as peak picking and least squares complex frequency domain methods) can usually meet the requirements for modal parameter identification; for nonlinear or time-varying structures, time domain methods (such as characteristic system realization algorithms and random subspace methods) or joint time-frequency analysis methods (such as short-time Fourier transform and Hilbert-Huang transform) are more suitable. During the modal analysis process, a structural modal identification model considering environmental factors is established. For example, in a temperature-changing environment, the stiffness matrix and mass matrix of the structure are corrected by introducing a temperature-dependent material property model; under airflow, the effect of aerodynamic loads on the structure is considered and incorporated into the dynamic equations of the structure for modal analysis. The modal parameter identification results are continuously optimized through iterative calculations and model verification. The consistency between the identified modal modes and the theoretical or reference modes is evaluated using indicators such as the modal confidence criterion (MAC) and mode shape correlation coefficient (MAC); the accuracy of the modal analysis results is judged by calculating parameters such as the relative error of the modal frequency and the rationality of the damping ratio. If the identification results do not meet the requirements, adjust the parameters or model assumptions of the modal analysis algorithm and recalculate until satisfactory modal parameter identification results are obtained.

[0064] In some embodiments of this application, the evaluation module visualizes the modal analysis results and performs structural evaluation based on the modal analysis results, including: visualizing the modal analysis results in the form of graphics, charts or animations; establishing a test result evaluation database; comparing and analyzing the modal analysis results under current environmental conditions with the modal analysis results under standard environmental or historical test data conditions; and evaluating the stability and reliability of the tested structural component.

[0065] In this embodiment, the modal parameters obtained from modal analysis, such as natural frequencies, mode shapes, and damping ratios, are graphically displayed using specialized visualization software. For example, 3D animation software is used to display the modal shapes of the structure, intuitively showing the vibration patterns of the structure under different modes; frequency response function curves are plotted to show the amplitude and phase changes of the structure's vibration at different frequencies; and modal confidence criterion (MAC) diagrams are generated to compare the similarity of modal shapes under different environmental conditions or between different test batches.

[0066] A database for evaluating test results is established to compare and analyze current test results with test data under standard environmental conditions, theoretical calculations, or test data from other similar structures. Statistical analysis methods are used to calculate the mean, standard deviation, coefficient of variation, and other statistical indicators of modal parameters to assess the stability and dispersion of the structure's dynamic characteristics. Based on the evaluation results, a basis is provided for the optimized design of the structure. For example, if a certain modal frequency or damping ratio is found to be too low under certain environmental conditions, leading to excessive structural vibration and affecting structural safety and comfort, the dynamic characteristics of the structure can be improved by modifying the design parameters, such as increasing stiffness, adjusting mass distribution, or optimizing damping design. Simultaneously, the test results can also provide a reference for structural health monitoring. By conducting regular modal tests and comparing changes in modal parameters at different times, signs of structural damage or performance degradation can be detected in a timely manner, allowing for appropriate maintenance measures to ensure the safe and reliable operation of the structure.

[0067] like Figure 2 As shown, the present invention also discloses a modal testing method based on environmental control, applied to the above-mentioned modal testing system based on environmental control, including: limiting and fixing the tested structural component.

[0068] Set environmental scene parameters according to experimental requirements, and set excitation mode according to environmental scene parameters and structural characteristics of the tested structure to excite the tested structure.

[0069] The test data of the structure under test is acquired, the test data is preprocessed, and modal analysis is performed based on the preprocessed test data.

[0070] The modal analysis results are visualized, and structural evaluation is performed based on the modal analysis results.

[0071] This invention improves the accuracy and reliability of modal testing. Through environmental control, it can simulate different working conditions, making the test results closer to actual conditions and providing strong support for structural design and optimization. Simultaneously, this invention makes the test data more intuitive and easier to understand through visualization and structural evaluation, facilitating analysis and judgment by engineers.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. 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 goods embodied 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.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will 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.

[0074] 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.

[0075] 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.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A modal testing system based on environmental control, characterized in that, include: The environment simulation module is configured to set environmental scenario parameters according to experimental requirements; The test platform module is configured to limit and fix the structural component under test; The excitation module is configured to switch the excitation mode according to the environmental scene parameters and the structural characteristics of the structure under test, and to excite the structure under test. The data acquisition module is configured to acquire test data of the structure under test; The data processing module is configured to preprocess the experimental data and perform modal analysis based on the preprocessed experimental data; The evaluation module is configured to visualize the modal analysis results and perform structural evaluation based on the modal analysis results.

2. The modal testing system based on environmental control according to claim 1, characterized in that, The environmental parameters include the temperature range, humidity range, air pressure conditions, and airflow speed.

3. The modal testing system based on environmental control according to claim 1, characterized in that, The environmental simulation module includes a temperature control unit, used to set a temperature range using a heater and a cooler; Humidity control unit, used to set humidity range using humidifiers and dehumidifiers; A pressure regulation unit is used to simulate air pressure conditions at different altitudes; The airflow control unit is used to set the airflow speed using an airflow speed generator.

4. The modal testing system based on environmental control according to claim 1, characterized in that, The test platform module includes a fixture, a three-dimensional guide rail, and a mounting platform. The fixture is set on the mounting platform and is used to hold the structural component under test. The three-dimensional guide rail is set on the mounting platform and is used to control the three-dimensional position of the excitation module.

5. The modal testing system based on environmental control according to claim 1, characterized in that, The excitation module includes: an electromagnetic exciter for providing periodic excitation force; Impact hammer, used to provide striking excitation; Acoustic exciter, used to provide acoustic load excitation.

6. The modal testing system based on environmental control according to claim 1, characterized in that, The data acquisition module includes several types of sensors, including acceleration sensors, displacement sensors, strain sensors, and pressure sensors. The test data of the tested structural component acquired by the data acquisition module through the sensors include vibration response data, deformation data, and force data.

7. The modal testing system based on environmental control according to claim 1, characterized in that, When the data processing module preprocesses the test data, the preprocessing includes noise reduction, filtering, and normalization.

8. The modal testing system based on environmental control according to claim 1, characterized in that, The data processing module performs modal analysis based on the preprocessed experimental data, including: Based on the structural characteristics of the tested structural component, the modal analysis algorithm is determined. A structural modal identification model based on environmental factors is established, and the model is iteratively calculated and corrected. Modal analysis was performed based on the modified structural modal identification model and preprocessed experimental data.

9. The modal testing system based on environmental control according to claim 1, characterized in that, The evaluation module visualizes the modal analysis results and performs structural evaluation based on the results, including: The modal analysis results can be visualized in the form of graphs, charts, or animations. Establish a database for evaluating test results, compare and analyze the modal analysis results under current environmental conditions with those under standard environmental conditions or historical test data conditions, and evaluate the stability and reliability of the tested structural components.

10. A modal testing method based on environmental control, applied to the modal testing system based on environmental control as described in any one of claims 1-9, characterized in that, include: Limit and fix the structural component under test; Set environmental scene parameters according to experimental requirements, set excitation mode according to environmental scene parameters and structural characteristics of the tested structure, and excite the tested structure. Acquire test data of the tested structural component, preprocess the test data, and perform modal analysis based on the preprocessed test data; The modal analysis results are visualized, and structural evaluation is performed based on the modal analysis results.

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