Thermal-vibration combined test system for thermal protection structure of spacecraft
By designing a combined thermal-vibration test system, the issues of synergy, adaptability, and reliability of thermal-vibration test systems in the verification of spacecraft thermal protection structures were resolved. This enabled accurate performance verification and damage warning for multi-material specimens, improving the stability and efficiency of the test.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-04-03
AI Technical Summary
Existing thermal-vibration testing systems suffer from problems such as insufficient thermal-vibration load coupling coordination, limited specimen compatibility, limited monitoring capabilities, and low reliability under high-temperature environments in the performance verification of spacecraft thermal protection structures, making it difficult to meet the high-performance verification requirements of next-generation spacecraft.
Design a thermal-vibration joint testing system that includes a specimen clamping module, a thermal loading module, a vibration loading module, a global monitoring module, a cooling protection module, and a collaborative adjustment module, to achieve coordinated and controllable loads, global specimen adaptation, global status monitoring, and high-temperature stable and reliable testing.
It improves the synergy of thermal-vibration coupling, adapts to specimens of various shapes and materials, realizes full-domain monitoring and high-temperature stability and reliability, provides accurate performance verification data, and ensures the safety and effectiveness of the test.
Smart Images
Figure CN121783477A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of performance testing and evaluation technology for spacecraft thermal protection structures, and more specifically, to a combined thermal-vibration testing system for spacecraft thermal protection structures. Background Technology
[0002] Thermal protection structures are widely used in spacecraft, aero-engines, high-speed aircraft, and other equipment. During their service life, they must withstand extremely complex environments for extended periods. They must not only withstand the high-temperature loads of hundreds to thousands of degrees Celsius during reentry, but also resist vibration loads from rocket engine vibrations during launch and aerodynamic disturbances during reentry. These two loads often act on the structure in a coupled "high-temperature-vibration" manner. The performance and reliability of the thermal protection structure directly determine the flight safety of the spacecraft. Therefore, verifying its mechanical properties, thermal protection efficiency, and durability through combined thermal-vibration testing has become a crucial step in its development.
[0003] Currently, the testing and verification methods for spacecraft thermal protection structures in the industry have gradually evolved from single thermal or vibration tests to combined thermal-vibration tests. However, existing thermal-vibration testing systems have significant limitations when directly applied to the performance testing and evaluation of spacecraft reentry thermal protection structures. On the one hand, the coupling and coordination of thermal and vibration loads are insufficient, resulting in timing discrepancies. For example, waiting for the temperature to rise to the target value before initiating vibration loading can lead to test risks on the specimen during non-designed single-load phases. On the other hand, the adaptability of specimens is limited, failing to cover the testing needs of multiple forms and materials. In particular, the test clamping device lacks differentiated preload pressure control. Insufficient preload for rigid materials leads to severe attenuation of vibration load transmission, while excessive preload for flexible materials can easily cause structural compression damage. It is difficult to balance the testing effectiveness and structural safety of specimens of different materials, and it cannot cover all types of testing scenarios for spacecraft thermal protection structures. In addition, there are shortcomings such as relatively limited monitoring capabilities and low reliability of the testing system under high-temperature environments, which significantly restrict testing efficiency, stability, and repeatability.
[0004] To address the aforementioned issues, there is an urgent need to design a thermal-vibration joint test system for thermal protection structures that can achieve "coordinated and controllable load, full-domain adaptability of test specimens, full-domain status monitoring, and high-temperature stability and reliability" in order to meet the high-performance verification requirements of thermal protection structures for next-generation spacecraft. Summary of the Invention
[0005] The purpose of this application is to provide a combined thermal-vibration testing system for spacecraft thermal protection structures, capable of solving at least one of the aforementioned technical problems. The specific solution is as follows:
[0006] According to a specific embodiment of this application, this application provides a thermal-vibration joint testing system for spacecraft thermal protection structures, including: a specimen clamp module, a thermal loading module, a vibration loading module, a global monitoring module, a cooling protection module, and a collaborative adjustment module;
[0007] The specimen clamping module is used to fix the specimen so that it is subjected to thermal and vibration loads in the correct posture; the thermal loading module is used to apply thermal loads to the surface of the specimen; the vibration loading module is used to apply vibration loads to the specimen; the global monitoring module is used to monitor the temperature, strain, acceleration and fatigue damage state of the specimen surface; the cooling protection module is used to actively cool the test device around the specimen and in the high-temperature range; and the coordinated adjustment module is used to dynamically control and adjust the synchronization and coordination of the coupled thermal and vibration loads, as well as the thermal deformation of the structure at high temperatures.
[0008] In some embodiments, the specimen clamping module includes: a fixed base, an adjustable clamping end, a pressure sensor, and an anti-slip layer;
[0009] The fixed base is rigidly connected to one side of the vibration loading module at one end and connected to the adjustable clamping end at the other end, so that the vibration load of the vibration loading module is transmitted without attenuation.
[0010] The adjustable clamping end is connected to the specimen clamping end through an interface that allows for adjustment of the clamping range;
[0011] The pressure sensor and the anti-slip layer are provided at the mounting section between the adjustable clamping end and the specimen, wherein the pressure sensor is used to monitor the clamping force of the adjustable clamping end.
[0012] In some embodiments, the heat loading module includes a temperature sensor, a temperature controller, an adjustable bracket, and multiple heating units; the temperature sensor is a high-temperature thermocouple installed on the surface of the specimen; each heating unit consists of multiple infrared quartz lamps arranged in a row, installed on different areas of the specimen surface via the adjustable bracket for differentiated heat loading; each heating unit is individually configured with a temperature controller, which can adjust the output heat flow according to the temperature controller's instructions to achieve the temperature control requirements of different areas of the specimen surface, simulating dynamic thermal conditions of gradient heating, constant temperature maintenance, and gradient cooling.
[0013] In some embodiments, the vibration loading module includes a vibration table, an accelerometer, a power amplifier, a vibration control system, and a thermal gradient connection structure. The vibration table is installed on a ground foundation and is used to output vibration loads of various waveforms and magnitudes in a specified direction under the command of the vibration control system. The accelerometer is installed on the surface of the vibration table and is used to collect the acceleration data of the vibration table in real time and feed it back to the vibration control system to achieve closed-loop control of the vibration. The vibration control system is connected to the vibration table through the power amplifier. The thermal gradient connection structure is installed between the specimen clamping module and the vibration table.
[0014] In some embodiments, the thermal gradient connection structure includes a three-layer gradient material structure, wherein the inner layer is made of a high-temperature resistant alloy material and is connected to the specimen clamp module; the middle layer is a transition layer used to balance the coefficient of thermal expansion; and the outer layer is a high-strength support material and is connected to the vibration table.
[0015] In some embodiments, the global monitoring module includes a DIC measurement system, an infrared thermal imager, and a laser vibrometer; the DIC measurement system is installed on one side of the back-heated surface of the specimen and is used to collect the strain data of the specimen surface in real time; the infrared imager is installed on one side of the back-heated surface of the specimen and is used to acquire the temperature field distribution on the surface of the specimen; the laser vibrometer is installed on one side of the back-heated surface of the specimen and is used to acquire the acceleration data of specific points on the surface of the specimen in real time. By acquiring the changes in the acceleration data, the fatigue damage state of the specimen during the test can be characterized and identified.
[0016] In some embodiments, the cooling protection module includes a zoned cooling device and a high-temperature protection chamber; the zoned cooling device cools the specimen clamping module and the vibration loading module through cooling water pipes; the high-temperature protection chamber includes a high-temperature resistant alloy shell, and an inert gas circulation system is provided inside the shell. The high-temperature protection chamber is installed around the specimen and the heat loading module to prevent the specimen from oxidizing at high temperatures and to isolate the influence of heat radiation on surrounding equipment.
[0017] In some embodiments, the coordinated adjustment module includes a main control unit and a dynamic adjustment unit. The main control unit interacts with the temperature sensor and the acceleration sensor signals. When the temperature reaches the target temperature, the main control unit drives the vibration control system to reach the peak vibration level. When the vibration load is applied for a target time, the main control unit drives the temperature controller to stop heating. The dynamic adjustment unit interacts with the laser vibrometer signal and adjusts the loading amplitude of the vibration table according to the thermal deformation of the specimen fixture module at high temperature. When thermal deformation causes a decrease in the stiffness of the specimen fixture module, the vibration acceleration is increased to ensure that the test magnitude of the specimen is not affected by the thermal deformation of the tooling.
[0018] In some embodiments, the fatigue damage state of the specimen is characterized by the change in the first natural frequency of the specimen obtained by the laser vibration meter. When the first natural frequency decreases to 70% of the initial value, the specimen is determined to be close to its fatigue failure threshold.
[0019] In some embodiments, the anti-slip layer is high-temperature resistant polyimide with a friction coefficient ≥0.6.
[0020] Compared with the prior art, the above-described solutions of this application have at least the following beneficial effects:
[0021] Enhanced thermal-vibration coupling synergy: The thermal-vibration joint test system for spacecraft thermal protection structures in this application makes the application of thermal and vibration loads more synchronous and coordinated, avoiding overtesting of specimens due to load application waiting time, and ensuring that the test load is closer to the actual service state of the spacecraft, providing accurate data support for the performance verification of thermal protection structures.
[0022] The test specimen adaptability covers multiple forms and materials: The thermal-vibration joint test system for spacecraft thermal protection structures in this application can be adapted to test specimens of multiple forms and materials, covering the testing needs of spacecraft thermal protection structures from small thermal insulation tiles to large compartments. By adjusting the installation pre-tightening pressure, a higher clamping force is applied to rigid materials such as silicon carbide ceramic matrix composites and metal-based honeycomb structures to ensure vibration transmission efficiency, while a lower clamping force is applied to materials such as flexible thermal insulation felt to avoid structural damage, thus meeting the testing and inspection needs of multiple types of thermal protection structures for spacecraft.
[0023] Breakthrough in comprehensive monitoring capabilities: The thermal-vibration combined testing system for spacecraft thermal protection structures in this application integrates multiple methods such as DIC, infrared thermal imaging, and laser vibration meter to monitor parameters such as strain, temperature, and vibration acceleration. It also uses the change of first-order natural frequency to provide early warning of fatigue damage to the specimen, enabling damage prediction in advance, ensuring comprehensive monitoring data, effectively identifying the failure risk of the specimen, and providing key data for the study of damage mechanisms of thermal protection structures.
[0024] Improved reliability of high-temperature testing systems: The thermal-vibration combined testing system for spacecraft thermal protection structures in this application effectively reduces the thermal deformation of tooling by adopting a thermal gradient connection structure, improves vibration transmission efficiency, and at the same time, combined with a cooling protection module, controls the temperature of non-test components to a lower temperature range, avoids high-temperature aging, effectively improves the service life of the testing system hardware, and ensures stable operation of the test. Attached Figure Description
[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:
[0026] Figure 1 This is a structural diagram of the thermal-vibration combined test system for spacecraft thermal protection structures according to the present invention.
[0027] Figure 2 This is an enlarged view of region A of the present invention.
[0028] Figure 3 This is a schematic diagram of the control principle of the thermal-vibration combined test system for spacecraft thermal protection structures according to the present invention.
[0029] The components include: 1. Specimen clamping module, 101. Fixed base, 102. Adjustable clamping end, 103. Pressure sensor, 104. Anti-slip layer; 2. Heat loading module, 201. Heating unit, 202. Temperature sensor, 203. Temperature controller, 204. Adjustable bracket; 3. Vibration loading module, 301. Vibration table, 302. Accelerometer, 303. Power amplifier, 304. Vibration control system, 305. Thermal gradient connection structure; 4. Global monitoring module, 401. DIC measurement system, 402. Infrared thermal imager, 403. Laser vibration meter; 5. Cooling protection module, 501. Zoned cooling device, 502. High temperature protection chamber; 6. Coordinated adjustment module, 601. Main control unit, 602. Dynamic adjustment unit; 7. Specimen. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail 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 in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0031] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.
[0032] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0033] It should be understood that although the terms "second," "third," etc., may be used to describe structures in the embodiments of this application, these structures should not be limited to these terms. These terms are only used to distinguish different structures. For example, without departing from the scope of the embodiments of this application, a second component may also be referred to as a second component, and similarly, a second component may also be referred to as a second component.
[0034] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.
[0035] Reference Figures 1-3 This application provides a thermal-vibration combined testing system for spacecraft thermal protection structures, including a specimen clamp module 1, a heat loading module 2, a vibration loading module 3, a global monitoring module 4, a cooling protection module 5, and a collaborative adjustment module 6. The specimen clamp module 1 is used to fix the specimen 7 so that it is subjected to thermal and vibration loads in the correct orientation; the heat loading module 2 is used to apply thermal loads to the surface of the specimen 7; the vibration loading module 3 is used to apply vibration loads to the specimen 7; the global monitoring module 4 is used to monitor the temperature, strain, acceleration, and fatigue damage state of the specimen 7 surface; the cooling protection module 5 is used to actively cool the test device surrounding the specimen 7 and within the high-temperature range; and the collaborative adjustment module 6 is used to dynamically control and adjust the synchronization and coordination of the coupled thermal and vibration loads, as well as the thermal deformation of the structure at high temperatures.
[0036] In some embodiments, the thermal-vibration combined testing system for spacecraft thermal protection structures includes a fixed base 101, an adjustable clamping end 102, a pressure sensor 103, an anti-slip layer 104, a heating unit 201, a temperature sensor 202, a temperature controller 203, an adjustable bracket 204, a vibration table 301, an acceleration sensor 302, a power amplifier 303, a vibration control system 304, a thermal gradient connection structure 305, a DIC measurement system 401, an infrared thermal imager 402, a laser vibration meter 403, a zoned cooling device 501, a high-temperature protective chamber 502, a main control unit 601, a dynamic adjustment unit 602, and a test specimen 7.
[0037] In some embodiments, the specimen clamping module 1 includes a fixed base 101, an adjustable clamping end 102, a pressure sensor 103, and an anti-slip layer 104. One end of the fixed base 101 is mounted on the vibration table 301 via a thermal gradient connection structure 305, and the other end is connected to the adjustable clamping end 102. The adjustable clamping end 102 is connected to the specimen 7 via an interface that allows for adjustable clamping range. A pressure sensor 103 and a high-temperature resistant polyimide anti-slip layer 104 are disposed at the mounting section between the adjustable clamping end 102 and the specimen 7. The clamping force is monitored by the pressure sensor 103. For rigid specimens 7, a clamping force of 30-50N is selected to ensure mechanical transmission characteristics. For flexible specimens 7, a clamping force of 5-15N is selected to prevent damage to the specimen. The anti-slip layer is made of high-temperature resistant polyimide with a coefficient of friction ≥0.6.
[0038] In some embodiments, the heat loading module 2 includes two heating units 201, a temperature sensor 202, a temperature controller 203, and an adjustable bracket 204. The temperature sensor 202 is a high-temperature resistant S-type thermocouple, mounted on the surface of the specimen 7. The heating unit 201 consists of several infrared quartz lamps arranged in a row, mounted on different areas of the specimen surface at a preset distance from the surface of the specimen 7, such as 5 mm, via the adjustable bracket 204, for differentiated heat loading. The adjustable bracket 204 is a quick-assembly, freely assembleable truss structure, allowing adjustment of the installation distance and angle of the infrared lamps in multiple degrees of freedom. An arc-shaped bracket can be customized for the curved surface of the specimen 7. Each heating unit 201 is individually equipped with an independent temperature controller 203, which adjusts the output heat flow according to the controller 203's instructions to achieve the temperature control requirements of different areas of the specimen 7 surface, simulating dynamic thermal conditions of gradient heating, constant temperature maintenance, and gradient cooling.
[0039] Optionally, the adjustable bracket 204 can be customized with an arc structure to accommodate curved surfaces 7.
[0040] In some embodiments, the vibration loading module 3 includes a vibration table 301, an acceleration sensor 302, a power amplifier 303, a vibration control system 304, and a thermal gradient connection structure 305. The vibration table 301 is installed on a ground foundation, and the acceleration sensor 302 is installed on the surface of the vibration table 301 to collect acceleration data of the vibration table 301 in real time and feed it back to the vibration control system 304 to achieve closed-loop vibration control. The vibration control system 304 is connected to the vibration table 301 through the power amplifier 303 and outputs commands to output vibration loads of various waveforms and magnitudes, such as sine waves and random waves, in a specified direction. The thermal gradient connection structure 305 is installed between the specimen clamp module 1 and the vibration table 301 and adopts a three-layer gradient material structure. The inner layer is made of high-temperature resistant alloy material GH4169 and is screwed to the specimen clamp module 1. The middle layer is a transition layer made of titanium alloy TC4 to balance the coefficient of thermal expansion, and the outer layer is a high-strength support material stainless steel 304, connected to the vibration table 301. The layers of the thermal gradient connection structure 305 are connected by vacuum brazing. A thermal isolation groove is set at the interface between the outer layer and the vibration table 301, and filled with high-temperature resistant ceramic insulation material to reduce the transfer of heat to the vibration table 301.
[0041] In some embodiments, the global monitoring module 4 includes a DIC measurement system 401, an infrared thermal imager 402, and a laser vibrometer 403. The DIC measurement system 401 is installed on the back side of the specimen 7 and collects strain data of the specimen 7 surface in real time during the test by spraying a high-temperature resistant speckled paint onto the surface of the specimen 7. The infrared imager 402 is installed on the back side of the specimen 7 to acquire the temperature field distribution on the surface of the specimen 7. The laser vibrometer 403 is installed on the back side of the specimen 7 to acquire acceleration data at specific points on the surface of the specimen 7 in real time. The fatigue damage state of the specimen 7 is identified by the change in the first-order natural frequency of the specimen 7 measured by the laser vibrometer 403. When the natural frequency drops to 70% of its initial value, fatigue failure of the specimen 7 is determined.
[0042] Optionally, for DIC measurement, a high-temperature resistant speckled paint should be sprayed onto the back surface of the specimen and then cured.
[0043] Optionally, when performing DIC measurements, it is advisable to use two or more cameras to collect strain data in all directions on the test surface of the specimen.
[0044] In some embodiments, the cooling protection module 5 includes a zoned cooling device 501 and a high-temperature protective chamber 502. The zoned cooling device 501 cools non-test components such as the test fixture 1 and the vibration table 301 surface through cooling water pipes. The cooling water temperature is ≤20℃, the flow rate is 10-20L / min, and the temperature of the non-test components is controlled at ≤80℃. The high-temperature protective chamber 502 has a shell made of high-temperature resistant alloy material and is equipped with a nitrogen circulation system inside, and is installed around the test piece 7 and the heat loading module 2. An observation window is opened on the surface of the high-temperature protective chamber 502 to provide a measurement field of view for the full-area monitoring module 4.
[0045] In some embodiments, the coordinated adjustment module 6 includes a main control unit 601 and a dynamic adjustment unit 602. The main control unit 601 interacts with the signals from the temperature sensor 202 and the acceleration sensor 302. When the temperature reaches the target temperature, the main control unit 601 drives the vibration control system 304 to reach the peak vibration level. When the vibration load is applied for the target time, the main control unit 601 drives the temperature controller 203 to stop heating. The main control unit 601 adopts a dual closed-loop coordinated control algorithm to ensure synchronous coupling of thermal and vibration loads, avoiding undertesting or overtesting. The dynamic adjustment unit 602 interacts with the laser vibrometer signal 403 and adjusts the loading amplitude of the vibration table 301 according to the amount of thermal deformation of the test fixture module 1 at high temperature. When thermal deformation causes a decrease in the stiffness of the test fixture 1, the vibration acceleration is increased to ensure that the test level of the specimen 7 is not affected by the thermal deformation of the fixture.
[0046] See attached document Figure 3The system control principle of this application is as follows: During the installation of specimen 7, the adjustable clamping end 102 is clamped by controlling the pre-tightening pressure of the pressure sensor 103. Specimen 7 is sequentially installed on the vibration table 301 via the clamping end 102 and the thermal gradient connection structure 305. Simultaneously, temperature sensor 202 and acceleration sensor 302 are installed at corresponding positions on specimen 7 and clamp 1. During the test, temperature sensor 202 collects test temperature data and feeds it back to temperature controller 203. Controller 203 issues a command to heating unit 201 to output the corresponding heat flow. Monitoring sensor 302 collects vibration acceleration data in real time and feeds it back to vibration control system 304. Vibration control system 304 controls the output according to the specified waveform and magnitude. The signal is amplified by power amplifier 303 to provide power to vibration table 301, enabling it to reach the specified vibration conditions. Simultaneously, main control unit 601 is activated to coordinate the control of heat loading module 2 and vibration loading module 3. When the temperature reaches the target temperature, main control unit 601 drives vibration control system 304 to reach the peak vibration magnitude. Once the vibration load has been applied for the target time, the main control unit 601 drives the temperature controller 203 to stop heating. After the temperature stabilizes, the active adjustment unit 602 is activated. The active adjustment unit reads the vibration acceleration data from the laser vibrometer 403 and adjusts the loading amplitude of the vibration table 301 according to the thermal deformation of the test fixture module 1 at high temperature.
[0047] The thermal-vibration test system for spacecraft thermal protection structures provided by this invention achieves uniform heat flux loading, precise single-degree-of-freedom vibration transmission, full-domain condition monitoring and damage early warning through the operation of each module system. The test data is accurate and reliable, and can accurately simulate the real service conditions of thermal protection structures of spacecraft and aero-engines. It effectively verifies the performance stability of thermal protection structures, meets the performance verification test and testing requirements of thermal protection structures of equipment such as spacecraft and aero-engines, and provides a reliable technical means for the performance verification of thermal protection structures.
[0048] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.
[0049] 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 combined thermal-vibration testing system for spacecraft thermal protection structures, characterized in that, include: The system includes a specimen fixture module, a heat loading module, a vibration loading module, a global monitoring module, a cooling protection module, and a collaborative adjustment module. The specimen clamping module is used to fix the specimen so that it is subjected to thermal and vibration loads in the correct posture; the thermal loading module is used to apply thermal loads to the surface of the specimen; the vibration loading module is used to apply vibration loads to the specimen; the global monitoring module is used to monitor the temperature, strain, acceleration, and fatigue damage state of the specimen surface; the cooling protection module is used to actively cool the test device around the specimen and within the high-temperature range; and the coordinated adjustment module is used to dynamically control and adjust the synchronicity and coordination of the coupled thermal and vibration loads, as well as the thermal deformation of the structure at high temperatures.
2. The system according to claim 1, characterized in that, The specimen clamping module includes: a fixed base, an adjustable clamping end, a pressure sensor, and an anti-slip layer; The fixed base is rigidly connected at one end to one side of the vibration loading module and at the other end to the adjustable clamping end, so that the vibration load of the vibration loading module is transmitted without attenuation. The adjustable clamping end is connected to the specimen clamping end through an interface that allows for adjustment of the clamping range; The pressure sensor and the anti-slip layer are provided at the mounting section between the adjustable clamping end and the specimen, wherein the pressure sensor is used to monitor the clamping force of the adjustable clamping end.
3. The system according to claim 1, characterized in that, The heat loading module includes a temperature sensor, a temperature controller, an adjustable bracket, and multiple heating units. The temperature sensor is a high-temperature thermocouple installed on the surface of the specimen. Each heating unit consists of multiple infrared quartz lamps arranged in a row and installed on different areas of the specimen surface via the adjustable bracket for differentiated heat loading. Each heating unit is individually equipped with a temperature controller, which can adjust the output heat flow according to the controller's instructions to achieve the temperature control requirements of different areas of the specimen surface, simulating dynamic thermal conditions of gradient heating, constant temperature maintenance, and gradient cooling.
4. The system according to claim 3, characterized in that, The vibration loading module includes a vibration table, an accelerometer, a power amplifier, a vibration control system, and a thermal gradient connection structure. The vibration table is installed on the ground foundation and is used to output vibration loads of various waveforms and magnitudes in a specified direction under the command of the vibration control system. The accelerometer is installed on the vibration table surface and is used to collect the acceleration data of the vibration table in real time and feed it back to the vibration control system to achieve closed-loop control of the vibration. The vibration control system is connected to the vibration table through the power amplifier. The thermal gradient connection structure is installed between the specimen clamping module and the vibration table.
5. The system according to claim 4, characterized in that, The thermal gradient connection structure includes a three-layer gradient material structure, wherein the inner layer is made of high-temperature resistant alloy material and is connected to the specimen clamp module; the middle layer is a transition layer used to balance the coefficient of thermal expansion; and the outer layer is a high-strength support material and is connected to the vibration table.
6. The system according to claim 4, characterized in that, The global monitoring module includes a DIC measurement system, an infrared thermal imager, and a laser vibrometer. The DIC measurement system is installed on the back side of the specimen to collect real-time strain data of the specimen surface. The infrared imager is installed on the back side of the specimen to acquire the temperature field distribution on the specimen surface. The laser vibrometer is installed on the back side of the specimen to acquire real-time acceleration data at specific points on the specimen surface. By acquiring changes in the acceleration data, the fatigue damage state of the specimen during the test can be characterized and identified.
7. The system according to claim 1, characterized in that, The cooling protection module includes a zoned cooling device and a high-temperature protection chamber. The zoned cooling device cools the specimen clamping module and the vibration loading module through cooling water pipes. The high-temperature protection chamber includes a high-temperature resistant alloy shell, and an inert gas circulation system is installed inside the shell. The high-temperature protection chamber is installed around the specimen and the heat loading module to prevent the specimen from oxidizing at high temperatures and to isolate the influence of heat radiation on surrounding equipment.
8. The system according to claim 6, characterized in that, The coordinated adjustment module includes a main control unit and a dynamic adjustment unit. The main control unit interacts with the temperature sensor and the acceleration sensor. When the temperature reaches the target temperature, the main control unit drives the vibration control system to reach the peak vibration level. When the vibration load is applied for a target time, the main control unit drives the temperature controller to stop heating. The dynamic adjustment unit interacts with the laser vibrometer and adjusts the loading amplitude of the vibration table according to the thermal deformation of the specimen fixture module at high temperature. When thermal deformation causes a decrease in the stiffness of the specimen fixture module, the vibration acceleration is increased to ensure that the test magnitude of the specimen is not affected by the thermal deformation of the tooling.
9. The system according to claim 6, characterized in that, The fatigue damage state of the specimen is characterized by the change in the first natural frequency of the specimen obtained by the laser vibration meter. When the first natural frequency decreases to 70% of the initial value, the specimen is determined to be close to its fatigue failure threshold.
10. The system according to claim 2, characterized in that, The anti-slip layer is made of high-temperature resistant polyimide with a friction coefficient ≥0.6.