A method for measuring strain and temperature decoupling of a component in an extreme environment based on a distributed optical fiber sensor

Abstract

This invention provides a method for decoupling the measurement of component strain and temperature based on distributed fiber optic sensors in extreme environments. The method includes: conducting temperature experiments with distributed fiber optic sensors at different temperatures to obtain the average temperature measurement pattern at the test location within the temperature-controlled stable region; conducting high-temperature strain experiments with distributed fiber optic sensors at different temperatures to obtain the strain measurement pattern at different test locations within the entire test area (temperature-controlled stable region + temperature transition region) at each temperature, and retrieving the temperature value at each test location based on the temperature measurement pattern; conducting thermo-decoupled measurements of special components in extreme environments, and verifying the temperature and strain measured by the distributed fiber optic sensors at the test location of the component using the obtained test patterns combined with high-temperature thermocouples and high-temperature strain gauges, thereby solving the problem of component strain and temperature measurement based on distributed fiber optic sensors in extreme environments.

Description

Technical Field

[0001] This invention belongs to the field of distributed optical fiber sensor measurement technology, specifically relating to a method for decoupling the measurement of component strain and temperature based on distributed optical fiber sensors in extreme environments. Background Technology

[0002] Fiber optic sensing technology has broad application prospects and value in defense industry, petrochemical industry, aerospace industry, and building health monitoring. In recent years, with the vigorous development of defense industry and aerospace technology, there is an urgent need to develop intelligent temperature strain sensors for extreme environments (vacuum, strong corrosion, strong radiation, extreme high temperature, strong electromagnetic interference, etc.) based on numerous application demands. Traditional electrical measurement technologies suffer from problems such as limited testing methods, susceptibility to electromagnetic interference, limited material temperature tolerance, and difficulty in integration, making their limitations in extreme environment applications increasingly apparent. Fiber optic sensing technology uses light waves as the carrier and optical fibers as the medium, leveraging the characteristic of light wave parameters being modulated by external physical quantities to achieve the sensing and measurement of environmental parameters. Compared to traditional electrical sensors, fiber optic sensors have advantages such as small size, passive operation, high sensitivity, high temperature resistance, radiation resistance, electromagnetic interference resistance, ease of multiplexing and network deployment, and ease of remote and distributed sensing, which can better meet the application needs of extreme environments.

[0003] Although fiber optic sensors have greater application prospects and potential in extreme environments compared to conventional electrical sensors, different operating environments can significantly impact the sensing characteristics of fiber optic sensors, as well as their packaging and testing materials, in complex engineering applications. Therefore, conducting experiments on the thermo-mechanical decoupling measurement of component temperature and strain based on distributed fiber optic sensors under extreme environments (vacuum, strong corrosion, strong radiation, extreme high temperatures, strong electromagnetic interference, etc.) can not only better guide the engineering applications of fiber optic sensors and achieve accurate measurement of temperature and strain parameters of key components and structures, but also provide reliable technical support for further evaluating the safety and reliability of key components and structures under extreme conditions, as well as optimizing structural design and related processes.

[0004] Fiber optic sensors can be categorized into single-point sensors and distributed sensors based on their measurement methods. In the field of high-temperature measurement, single-point sensors are currently the most widely used and technologically mature. Temperature measurement applications primarily include blackbody radiation sensors, Bragg fiber grating sensors, and Fabry-Perot sensors. High-temperature strain measurement primarily includes Bragg fiber grating sensors and Fabry-Perot sensors. Single-point sensors face technical challenges such as limited measurement points and difficulties in integration and network deployment. Distributed sensors, on the other hand, integrate optical signal transmission and parameter sensing within the fiber optic cable, acting as both a transmission and sensing medium. By analyzing the characteristics of scattered light propagating through the fiber, the measured value at each sensing point along the fiber's length can be detected, enabling continuous parameter measurement throughout the entire fiber optic link. Currently, distributed sensors are mainly used for extreme temperature measurements.

[0005] Conventional methods for measuring the temperature characteristics of distributed fiber optic sensors typically employ a constant-temperature water / oil bath method, applicable to temperatures up to 300℃. Strain measurement methods use fixed-point tensile testing, equal-strength beam methods, or fixed-pulley methods, generally only measuring strain characteristics at room temperature. For high-temperature environments above 300℃, the high-temperature strain characteristics change significantly with increasing temperature range, necessitating testing of strain characteristics at different temperatures. This invention uses a temperature-controlled stable region instead of a constant-temperature water / oil bath for stable temperature loading and employs the fixed-point tensile method to determine the strain characteristics of distributed fiber optic sensors under high-temperature conditions at different temperatures. Summary of the Invention

[0006] This invention provides a decoupled measurement method for component strain and temperature based on distributed optical fiber sensors in extreme environments. The purpose is to solve the problem that the temperature testing range of the constant temperature water bath / oil bath method is applicable to within 300℃. This invention is based on the optical fiber thermo-mechanical decoupling method and is used to test the strain characteristics of optical fiber sensors in high temperature environments exceeding 300℃.

[0007] Therefore, the present invention adopts the following technical solution:

[0008] A method for decoupling strain and temperature measurement of components in extreme environments based on distributed fiber optic sensors includes the following steps:

[0009] The testing apparatus includes a demodulation system, a fiber optic sensor, a high-temperature armored thermocouple, a precision electric displacement platform, a clamping device, and a high-temperature furnace. The fiber optic sensor is installed inside the high-temperature furnace, which is used to heat the fiber optic sensor. Two clamping devices are located on the left and right sides of the high-temperature furnace, respectively, for clamping and fixing the fiber optic sensor. The precision electric displacement platform is located on the front clamping device for pulling the fiber optic sensor to extend. The high-temperature armored thermocouple is fixed in the middle of the high-temperature furnace for measuring temperature.

[0010] The measurement method includes the following steps:

[0011] Step 1: The head end of the fiber optic sensor is connected to the demodulation system via fusion splicing, and the tail end passes through the high-temperature heating furnace and is fixed to the precision electric displacement platform by the clamping device; the end of the high-temperature armored thermocouple is fixed in the middle position of the high-temperature heating furnace; the precision electric displacement platform is controlled to move radially along the fiber optic sensor to straighten the fiber optic sensor and ensure that there is no slippage between the clamping device and the fiber optic sensor.

[0012] Step 2: Conduct a temperature response experiment on the fiber optic sensor, and control the heating rate of the high-temperature furnace according to the experimental design.

[0013] The thermocouple control software records the temperature data x11 at the middle test position in the temperature control and stabilization zone of the high-temperature heating furnace. At the same time, the demodulation system collects fiber optic parameter data from more than three test positions in the temperature control and stabilization zone in real time and calculates the average optical parameter y11.

[0014] Through multiple measurements, the temperature data and average optical parameters were numerically fitted to obtain the functional relationship between temperature x11 and average optical parameter y11, Equation 1.

[0015] Step 3: Conduct a high-temperature strain test on the fiber optic sensor, divide the test temperature range into equal intervals, and heat it sequentially to the required temperature xi2 (i=1,2,…,m, where m is the number of test temperature intervals) in a high-temperature heating furnace;

[0016] The test fiber is subjected to strain zj2 at temperature xi2 (j=0,1∆,2∆,…,n∆,n is the number of stretching times,∆ is the single strain loading amount) through a high-precision electric displacement platform, and the corresponding optical parameter data yjk2 (j=0,1∆,2∆,…,n∆,k=1,2,…,N,N is the number of different test positions) at different test locations in the test area is demodulated by the demodulation system.

[0017] Through multiple measurements, numerical fitting was used again to obtain the functional relationship between strain zj2 and optical parameter yjk2 at N test locations under different temperatures xi2;

[0018] By combining the functional relationship 1, the temperature values ​​xk2 at N test locations under different temperatures xi2 are calculated, and the strain and temperature thermodynamics at different test locations of the distributed sensor under high temperature environment are decoupled, thereby realizing the measurement of dual parameters of temperature and strain.

[0019] Step 4: Use a high-temperature resistant adhesive to encapsulate the high-temperature thermocouple, high-temperature strain gauge and distributed fiber optic sensor on the surface of the special component. Place the encapsulated special component in vacuum, strong corrosion, strong radiation, strong electromagnetic interference, extreme high temperature or other extreme environments to perform thermo-mechanical decoupling measurements on the special component.

[0020] The optical parameter data of special components in extreme environments are demodulated using a demodulation system. The temperature and high-temperature strain data of the special components are measured by combining the temperature and strain test laws obtained in steps two and three. The temperature and strain of the special components measured by the distributed fiber optic sensor are verified and corrected using high-temperature thermocouples and high-temperature strain gauges.

[0021] Furthermore, in step 4, the method for testing the vacuum environment is as follows:

[0022] The specially packaged fiber optic sensor components are placed in a vacuum heating furnace, and the fiber optic sensor lead-out points are sealed using vacuum sealant or vacuum flanges to ensure the airtightness of the furnace cavity. The vacuum level inside the high-temperature furnace is maintained at 10... 5 -10 2 MPa, conduct thermal decoupling tests from room temperature to 100℃.

[0023] Furthermore, in step 4, the testing method for the highly corrosive environment is as follows:

[0024] The impact of highly corrosive environments on the thermal decoupling of fiber optic sensors mainly lies in the accumulation of surface damage. A salt spray test chamber was used to simulate atmospheric salt spray conditions. A 5% sodium chloride aqueous solution with a pH adjusted to neutral was used as the spray solution. The salt spray deposition rate was between 1 and 2 ml / 80 cm²·h. The fiber optic sensor was subjected to the salt spray environment for at least 72 hours. After the salt spray experiment, the sensor was dried and then encapsulated onto a special component, placed in a high-temperature furnace, and subjected to thermal decoupling tests from room temperature to 100°C.

[0025] Furthermore, in step 4, the testing method for the strong radiation environment is as follows:

[0026] The impact of strong radiation environments on the thermal decoupling of fiber optic sensors mainly lies in the accumulation of internal structural damage. Fiber optic sensors were irradiated using a radiation generator at doses of 0, 1 mgy, 4 mgy, 7 mgy, and 10 mgy. The irradiated sensors were then encapsulated onto special components and placed in a high-temperature furnace for thermal decoupling tests ranging from room temperature to 100°C.

[0027] Furthermore, in step 4, the testing method for a strong electromagnetic interference environment is as follows:

[0028] Electromagnetic interference was generated using an electromagnetic generator to simulate the extreme environment of strong electromagnetic interference. The electromagnetic generator was placed next to the experimental equipment to generate electromagnetic interference at a frequency of 1-10 GHz. At the same time, fiber optic sensors were encapsulated on the surface of special components and placed in a high-temperature heating furnace to conduct thermo-decoupling tests from room temperature to 100°C.

[0029] Furthermore, in step 4, the test method for the extreme high-temperature environment is as follows:

[0030] The fiber optic sensor was encapsulated onto a special component and placed in a high-temperature heating furnace at a heating rate of 10℃ / min. Thermal decoupling tests were conducted by holding the temperature at 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 700℃, 800℃, 900℃ and 1000℃ for 60 minutes each.

[0031] Furthermore, the fiber optic sensor employs a high-temperature resin-coated single-mode fiber optic sensor, a metal-coated single-mode fiber optic sensor, or a Bragg fiber grating multiplexed array. The demodulation system includes, but is not limited to, an optical time-domain reflectometry demodulator and an optical frequency-domain reflectometry demodulator. The high-temperature strain gauge includes, but is not limited to, high-temperature resistance strain gauges and high-temperature fiber grating strain gauges. The precision electric displacement platform is primarily controlled by software programs, with repeatability accuracy controlled within ±5μm.

[0032] Furthermore, the clamping device uses a high-temperature resistant alloy plate, and the clamping method is to fix it with a high-temperature resistant fiber optic clamp or a high-temperature resistant adhesive.

[0033] Furthermore, high-temperature armored thermocouples include, but are not limited to, type K, type S, and type B thermocouples.

[0034] Furthermore, the special components to be tested include, but are not limited to, high-temperature resistant ceramics, high-temperature resistant composite materials, and high-temperature alloys.

[0035] The high-temperature heating furnace uses program-controlled loading temperature. According to the test requirements, holes are made on both sides of the high-temperature heating furnace at horizontal positions to ensure that the optical fiber passes through the high-temperature furnace in a straight line and that the lower end can be inserted into a high-temperature armored thermocouple.

[0036] Feasibility explanation of the experimental plan:

[0037] This invention addresses five different extreme environments encountered in actual testing of fiber optic sensors: vacuum, strong corrosion, strong radiation, extreme high temperature, and strong electromagnetic interference. The experimental design analyzes the impact of these extreme environments on the sensing performance of fiber optic sensors, and references relevant testing standards and specifications for samples tested under laboratory conditions in these five extreme environments. Reasonable experimental parameters and standard experimental procedures and methods are provided. Therefore, the experimental scheme for decoupling temperature and strain measurement of components based on distributed fiber optic sensors under these different extreme environments is highly operable and feasible.

[0038] The beneficial effects of this invention are as follows:

[0039] The strain and temperature decoupling measurement method for components in extreme environments based on distributed optical fiber sensors disclosed in this invention involves fixing the distributed optical fiber sensor on clamping devices on both sides, conducting high-temperature response experiments under extreme environments, measuring the temperature at three test locations in the temperature-controlled stable region, and obtaining the temperature measurement patterns; conducting high-temperature strain experiments on the distributed optical fiber sensor at different temperatures, using a precision electric displacement slide to apply strain at different temperatures, obtaining the strain measurement patterns at different test locations at each temperature, thus achieving the purpose of structural measurement of strain and temperature using the distributed optical fiber sensor; and conducting strain and temperature measurements of special components under extreme environments, thereby achieving accurate measurement of the strain and temperature of special components under extreme environments. Attached Figure Description

[0040] Figure 1 The figure shows the quadratic polynomial fitting curves of temperature and frequency shift in the high-temperature response experiment in the example.

[0041] Figure 2 Temperature values ​​at different locations were calculated by reversing the temperature testing pattern.

[0042] Figure 3 This is a schematic diagram of the component strain and temperature decoupling test device based on distributed optical fiber sensors designed for this invention.

[0043] Figure 4 A schematic diagram of different heating zones in a high-temperature heating furnace;

[0044] Figure 5 This is a schematic diagram of the clamping device designed for this invention;

[0045] Figure 6 A schematic diagram of the encapsulated alumina ceramic component;

[0046] Figure 7 A comparison chart of temperatures measured by distributed fiber optic sensors and temperatures measured by thermocouples;

[0047] Figure 8 Frequency shift response curves of alumina ceramic components acquired by fiber optic sensors at different temperatures;

[0048] In the diagram: 1-Demodulation system, 2-Fiber optic sensor, 3-High-temperature armored thermocouple, 4-Precision electric displacement platform, 5-Clamping device, 6-High-temperature heating furnace, 7-Temperature transition zone, 8-Temperature control stabilization zone, 9-Fixing screw hole, 10-High-temperature resistant adhesive, 11-Special component, 12-High-temperature strain gauge. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0050] Step 1: Test the gold-plated single-mode fiber optic sensor 2. One end is connected to the OSI-D high-precision dynamic optical frequency domain demodulation system 1 via a fusion spliced ​​fiber optic patch cord. The other end is fused with a 10-20cm long coreless fiber to solve the problem of strong Fresnel reflection at the tail end affecting the measurement signal. This fiber is then passed through a high-temperature heating furnace 6 and fixed to a precision electric displacement platform 4 via a clamping device 5. The end of the high-temperature armored thermocouple 3 is fixed in the middle of the high-temperature heating furnace 6. By controlling the precision electric displacement platform 4 to pull the fiber optic sensor 2 radially a suitable distance, the fiber is straightened, ensuring no slippage between the clamping device 5 and the fiber optic sensor 2. A high-temperature resistant adhesive 10 is used to encapsulate the gold-plated fiber optic sensor 2 and the high-temperature strain gauge 12 onto the alumina ceramic special component 11 at the measurement location.

[0051] Step two: A high-temperature response experiment was conducted on the gold-plated fiber optic sensor 2. Temperature was applied to the sensor using a high-temperature furnace 6 at a heating rate of 10℃ / min, and data from the high-temperature sheathed thermocouple 3 inside the furnace was recorded using software. 1 The OSI-D high-precision dynamic optical frequency domain demodulation system 1 was used to collect fiber frequency shift data at three test locations within the temperature-controlled stable region 8 in real time, and the arithmetic average frequency shift y1 was calculated. 1 . Reference Figure 1 As shown, for temperature x1 1 and average frequency shift y1 1 After performing two polynomial fitting operations, we obtain the following relational equation:

[0052] y1 1 (x1 1 )=A*(x1 1 ) 2 +B *x1 1 + C

[0053] Step 3, test temperature x i 2 (i=1,2,…,10) are divided into equal intervals of 100℃, 200℃,…,1000℃, and heated sequentially to the required temperature x by a high-temperature heating furnace 6. i 2 The gold-plated fiber optic sensor 2 was tested by applying a temperature x through a precision electric displacement platform 4. i 2 Lower strain z j 2(j=0,50µm,…,15*50µm), and the frequency shift y at different test locations in the entire test area (temperature-controlled stable region 8 + temperature transition region 7) is acquired using the OSI-D high-precision dynamic optical frequency domain demodulation system 1. jk 2 (j=0, 50µm, ..., 15*50µm, k=1, 2, ..., 20). Different temperatures x were obtained through linear fitting. i 2 strain z j 2 and frequency shift y jk 2 The functional relationship yields relation 2 as shown below:

[0054] z j 2 (x i 2 )= K(x i 2 )*[y jk 2 (x i 2 )- y 0k 2 (x i 2 )]+z2 2 (x i 2 )

[0055] K (x i 2 (z2) represents the strain coefficients obtained by fitting at different temperatures. 2 (x i 2 ( ) represents the thermal expansion strain of the optical fiber at different temperatures. (Refer to...) Figure 2 As shown, y 0k 2 Substituting into equation 1, we can calculate x at different temperatures. i 2 Temperature values ​​x at various locations before stretching k 2 This allows for the decoupling of strain and temperature in distributed sensors under high-temperature conditions, thereby enabling the simultaneous measurement of both temperature and strain parameters.

[0056] Step four: Perform thermo-decoupling measurements on the encapsulated alumina ceramic special component 11. Place the alumina ceramic special component 11 into the high-temperature heating furnace 6 and test at temperature x. i 3(i=1,2,…,8) Temperatures are divided at equal intervals of 100℃, 200℃, …, 800℃. Temperature data is acquired using high-temperature armored thermocouples 3 and control software. High-temperature strain gauges 4 are used to acquire the corresponding high-temperature strain of the alumina ceramic special component 11. The composite frequency shift response data of the alumina ceramic special component 11 is demodulated using an OSI-D high-precision dynamic optical frequency domain demodulation system 1, with reference to… Figure 8 Combining the temperature and high-temperature strain data of the alumina ceramic special component 11 obtained in steps two and three, the theoretical model for temperature and strain measurement was calculated using the gold-plated fiber optic sensor 2. (Referring to...) Figure 7 The temperature and strain of the alumina ceramic special component 11 measured by the gold-plated fiber optic sensor 2 were verified and corrected using a high-temperature armored thermocouple 3 and a high-temperature strain gauge 12.

Claims

1. A method for decoupling the measurement of component strain and temperature based on distributed fiber optic sensors in extreme environments, characterized in that, Includes the following steps: The testing apparatus includes a demodulation system, a fiber optic sensor, a high-temperature armored thermocouple, a precision electric displacement platform, a clamping device, and a high-temperature furnace. The fiber optic sensor is installed inside the high-temperature furnace, which is used to heat the fiber optic sensor. Two clamping devices are located on the left and right sides of the high-temperature furnace, respectively, for clamping and fixing the fiber optic sensor. The precision electric displacement platform is located on the front clamping device for pulling the fiber optic sensor to extend. The high-temperature armored thermocouple is fixed in the middle of the high-temperature furnace for measuring temperature. The measurement method includes the following steps: Step 1: The head end of the fiber optic sensor is connected to the demodulation system via fusion splicing, and the tail end passes through the high-temperature heating furnace and is fixed to the precision electric displacement platform by the clamping device; the end of the high-temperature armored thermocouple is fixed in the middle position of the high-temperature heating furnace; the precision electric displacement platform is controlled to move radially along the fiber optic sensor to straighten the fiber optic sensor and ensure that there is no slippage between the clamping device and the fiber optic sensor. Step 2: Conduct a temperature response experiment on the fiber optic sensor, and control the heating rate of the high-temperature furnace according to the experimental design. Thermocouple control software records temperature data at the middle test position in the temperature control stability zone of the high-temperature heating furnace x1 1 Simultaneously, a demodulation system is used to collect fiber optic parameter data from more than three test locations in the temperature-controlled stable area in real time, and the average optical parameter y1 is calculated. 1 ; Through multiple measurements, numerical fitting was performed on the temperature data and average optical parameters to obtain temperature x1. 1 and average optical parameter y1 1 Functional relation 1; Step 3: Conduct a high-temperature strain test on the fiber optic sensor. Divide the test temperature range into equally spaced intervals and heat it sequentially to the required temperature x using a high-temperature furnace. i 2 (i=1,2,…,m, where m is the number of test temperatures); The test fiber is subjected to a temperature x through a high-precision electric displacement platform. i 2 strain z j 2 (j=0,1∆,2∆,…,n∆, n is the number of tensile cycles, ∆ is the single strain loading), and the corresponding optical parameter data y at different test positions in each test area are demodulated using a demodulation system. jk 2 (j=0,1∆,2∆,…,n∆,k=1,2,…,N,N is the number of different test locations); Through multiple measurements, numerical fitting was used again to obtain the values ​​of x at different temperatures. i 2 Strain z at the next N test locations j 2 and optical parameters y jk 2 Functional relation 2; By combining the functional relationship 1, we can calculate x at different temperatures. i 2 Temperature values ​​x at the next N test locations k 2 This enables the thermo-strain and temperature decoupling of distributed sensors at different test locations under high-temperature conditions, thereby achieving the measurement of both temperature and strain parameters. Step 4: Use a high-temperature resistant adhesive to encapsulate the high-temperature thermocouple, high-temperature strain gauge and distributed fiber optic sensor on the surface of the special component. Place the encapsulated special component in vacuum, strong corrosion, strong radiation, strong electromagnetic interference, extreme high temperature or other extreme environments to perform thermo-mechanical decoupling measurements on the special component. The optical parameter data of special components in extreme environments are demodulated using a demodulation system. The temperature and high-temperature strain data of the special components are measured by combining the temperature and strain test laws obtained in steps two and three. The temperature and strain of the special components measured by the distributed fiber optic sensor are verified and corrected using high-temperature thermocouples and high-temperature strain gauges.

2. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, In step four, the method for testing the vacuum environment is as follows: The special components encapsulated with the fiber optic sensor are placed in a vacuum heating furnace, and the fiber optic sensor lead-out positions are sealed using vacuum sealant or vacuum flanges to ensure the airtightness of the furnace cavity; the vacuum level inside the high-temperature furnace is maintained at 10. 5- 10 2 MPa, start the vacuum heating furnace to perform thermo-decoupling test.

3. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, In step four, the testing method for highly corrosive environments is as follows: A salt spray test chamber was used to simulate the salt spray environment in the atmosphere. A sodium chloride aqueous solution was used, with the pH value adjusted to the neutral range as the spray solution. The salt spray deposition rate was 1–2 ml / 80 cm. 2 Between .h, the fiber optic sensor is treated in a salt spray environment for no less than 72h; after the salt spray experiment is completed and dried, it is packaged onto a special component and placed in a high-temperature heating furnace for thermal decoupling test.

4. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, In step four, the testing method for a strong radiation environment is as follows: The fiber optic sensor is irradiated using a radiation generator, and the radiation intensity is adjusted step by step according to the gradient. The irradiated fiber optic sensor is then encapsulated on a special component and placed in a high-temperature heating furnace for thermal decoupling testing.

5. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, In step four, the testing method for strong electromagnetic interference environments is as follows: Electromagnetic interference is generated by placing an electromagnetic generator next to the experimental equipment at a frequency of 1-10 GHz. At the same time, an optical fiber sensor is encapsulated on the surface of a special component and placed in a high-temperature heating furnace for thermal decoupling testing.

6. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, In step four, the test method for extreme high-temperature environment is as follows: The fiber optic sensor is encapsulated onto a special component and placed in a high-temperature heating furnace at a heating rate of 10℃ / min. Thermal decoupling tests are then conducted by holding the sensor at 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 700℃, 800℃, 900℃, and 1000℃ for at least 60 minutes each.

7. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, The fiber optic sensor uses a high-temperature resistant resin-coated single-mode fiber optic sensor, a metal-coated single-mode fiber optic sensor, or a Bragg fiber grating multiplexed array.

8. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, The clamping device uses a high-temperature resistant alloy plate, and the clamping method is to fix it with a high-temperature resistant fiber optic clamp or a high-temperature resistant adhesive.

9. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, High-temperature armored thermocouples include, but are not limited to, type K, type S, and type B thermocouples.

10. The method for decoupling component strain and temperature measurement based on distributed fiber optic sensors in extreme environments according to claim 1, characterized in that, The special components to be tested include, but are not limited to, high-temperature resistant ceramics, high-temperature resistant composite materials, and high-temperature alloys.

Images