Thermal protection coating accelerated life evaluation method close to service environment profile

Abstract

The invention discloses a thermal protection coating accelerated life evaluation method close to a service environment profile. The method comprises the following steps: constructing a damp heat test spectrum for simulating a storehouse storage environment and a combined test spectrum for simulating a hang-off duty environment; determining the equivalent test time of a constant / chord variation damp heat test equivalent to one year of actual storehouse storage in the thermal protection coating life evaluation combined test profile, and carrying out an accelerated test equivalent to the expected service life of the thermal protection coating; and after the test is finished, evaluating whether the service life of the thermal protection coating meets the expected service life according to a comparison result. The method can be used for accurately and effectively evaluating the service life of the thermal protection coating in the environment close to the actual service environment, and can provide method support for material / process screening, service life estimation and model environment adaptability and reliability improvement of the thermal protection coating in the model development stage.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal protection coating life assessment, and particularly relates to an accelerated life assessment method for thermal protection coatings close to the service environment profile. Background Art

[0002] Thermal protection coatings are one of the main coating materials for heat protection of missile engines and their nacelles. They have excellent high-temperature resistance, ablation resistance, high specific heat capacity and low thermal conductivity, can effectively improve the ability of the shell surface to resist airflow erosion and air friction heat, reduce the temperature inside the nacelle, and improve the reliability of the missile during high-speed flight. Due to the extremely complex microstructure, geometry and service environment of the coating, its performance will gradually decline under the long-term environmental action, and failure phenomena such as cracking and spalling will occur, which seriously restricts the safe application of thermal protection coatings.

[0003] At present, the tests adopted for thermal protection coating life assessment at home and abroad are mostly test methods for single environments such as high temperature or temperature cycle shock. For example: The life prediction method based on continuous damage accumulation believes that during the service process of thermal barrier coatings, it is mainly affected by the periodic heating-cooling-heating environment. During each thermal cycle, residual stresses caused by factors such as interface oxidation, high-temperature sintering and mismatch continuously damage the coating system. However, since missile thermal protection coatings will experience various complex environments such as transportation, storage in the warehouse, and hanging flight on duty during the entire life cycle, the existing life test methods for thermal protection coatings only strengthen single environmental factors and cannot truly and effectively simulate the combined action of various environmental factors, resulting in a large difference between the evaluation results and the actual situation, and cannot meet the life assessment requirements of missile thermal protection coatings. Summary of the Invention

[0004] At least to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide an accelerated life assessment method for thermal protection coatings close to the service environment profile.

[0005] To achieve the above purpose, the present invention provides the following technical solutions.

[0006] An accelerated life assessment method for thermal protection coatings close to the service environment profile, the steps include: Step 1, construct a damp heat test spectrum simulating the warehouse storage environment; Step 2, construct a combined test spectrum simulating the hanging flight on duty environment; Step 3, according to the principle of environmental effect equivalence, determine the equivalent test time of the constant / variable damp heat test in the life assessment combined test profile of the thermal protection coating equivalent to 1 year of actual warehouse storage; Step 4: Evaluate the combined test profile based on the obtained equivalent test time and the life of the protective coating, and conduct an accelerated test for the thermal protective coating equivalent to the expected service life; after the test, compare the performance test results of the samples with the failure threshold, and evaluate whether the life of the thermal protective coating can meet the expected life according to the comparison results.

[0007] Further, the steps for constructing the damp heat test spectrum simulating the storage environment in the warehouse in Step 1 include: Step 11: Collect the hourly environmental factor data of temperature and relative humidity in the storage warehouse of the thermal protective coating for at least one natural year, and analyze its temperature and humidity characteristics and variation rules. Step 12: Determine the stress loading method for the damp heat accelerated test according to the obtained temperature and humidity characteristics and rules. If the temperature fluctuation is less than 3°C and the relative humidity fluctuation is less than 3%, the constant damp heat test method is adopted; otherwise, the cyclic variable damp heat test method with a cycle of 24 hours is adopted. Step 13: Determine the magnitude levels of temperature and humidity in the obtained damp heat test method: If the constant damp heat test method is adopted, the test temperature is determined to be 90°C, and the relative humidity is determined according to the average value within one natural year in the warehouse. If the cyclic variable damp heat test method is adopted, the maximum test temperature is determined to be 90°C, the minimum test temperature is determined according to the difference between the highest temperature and the lowest temperature within one natural year in the warehouse, and the maximum relative humidity and the minimum relative humidity are the same as the highest relative humidity and the lowest relative humidity within one natural year in the warehouse. Further, the steps for constructing the combined test spectrum simulating the environment of hanging flight and on-duty in Step 2 include: Step 21: Simulate the damp heat test load spectrum of the airport ground atmosphere environment, including the temperature spectrum and the relative humidity spectrum: The temperature magnitudes corresponding to three typical weather conditions are mainly determined according to GB / T 1920. Among them, the ground temperature under standard weather conditions is 15°C, and the ground temperatures on hot days and cold days are determined to be 45°C on hot days and -54°C on cold days respectively according to the risk rate of 10% for the tested product to encounter extreme temperatures in accordance with HB5652.1; the relative humidity corresponding to standard weather conditions is determined to be 80%, and when the temperature on cold days is below 0°C, the humidity is not controlled. Step 22: Simulate the comprehensive test load spectrum of the in-air hanging flight environment, including the damp heat test load spectrum and the vibration spectrum of the in-air hanging flight environment: Determine the temperature and relative humidity load spectra corresponding to each stage during the missile hanging flight according to the analysis results of the hanging flight environment and the typical flight mission profile of the carrier aircraft; determine the vibration spectrum forms corresponding to each stage of the carrier aircraft's takeoff, climb, patrol standby, cruise, and descent and landing according to the corresponding requirements in GJB899A and the typical mission profile of the carrier aircraft.

[0008] Further, Step 3 specifically includes: Step 31: Conduct comparative tests on the thermal protection coating samples under three different temperature and humidity stresses respectively. At least 8 - 10 tests on the coating adhesion performance should be carried out under each test condition, and the number of parallel samples for each test should be no less than 5 pieces; Step 32: Based on the periodic performance test data of the thermal protection coating samples, calculate the performance retention rate (t i , P i ) corresponding to different test times, and construct the performance degradation law models of the samples under the three test conditions respectively; P i represents the performance retention rate Step 33: Use the established models to calculate the respective corresponding test times when the performance retention rate of the thermal protection coating drops to different values under the three test conditions, namely (t 11 , t 21 , t 31 ), (t 12 , t 22 , t 32 ), (t 13 , t 23 , t 33 )…(t 1n , t 2n , t 3n ); Step 34: Use the temperature and humidity environmental factor coupling model formula [1] to calculate the coupling values corresponding to the three test conditions and test times respectively, namely (W 11 , W 21 , W 31 ), (W 12 , W 22 , W 32 ), (W 13 , W 23 , W 33 )…(W 1n , W 2n , W 3n ); In the formula, W is the temperature and humidity coupling cumulative value for the selected storage duration, t is the time, H(t) is the relative humidity corresponding to the time t, T(t) is the absolute temperature corresponding to the time t, C is a constant, W 1n represents the cumulative stress coupling value at the nth test under the first test stress condition, W 2n represents the cumulative stress coupling value at the nth test under the second test stress condition, W 3n represents the cumulative stress coupling value at the nth test under the third test stress condition; Step 35: Based on the obtained temperature-humidity coupling cumulative quantity value data under the three test conditions, establish a correlation relationship model between the coupling cumulative quantity value and the test temperature, calculate the corresponding temperature-humidity coupling cumulative quantity values (W 01 , W 02 , W 03 , …, W 0n ) in the storage environment, and then calculate a set of correction coefficients (W 11 / W 01 , W 12 / W 02 , …, W 1n / W 0n ) based on the environmental effect equivalence. Take the average value to obtain the correction coefficient of the temperature-humidity coupling cumulative quantity value of the accelerated storage test environment relative to the normal storage environment; Step 36: Using the temperature-humidity environmental factor data of one natural year in the warehouse as the input, calculate the temperature-humidity coupling cumulative quantity value of the warehouse in one year by using the temperature-humidity coupling model formula [1]; Step 37: Calculate the corresponding temperature-humidity coupling cumulative quantity value of the accelerated storage test environment according to the obtained temperature-humidity coupling cumulative quantity value correction coefficient, and use the temperature-humidity coupling model formula [1] to back-calculate the equivalent test time. Preferably, the thermal protection coating is a silicone rubber heat protection coating.

[0009] Beneficial effects: The method of the present invention can be used for accurate and effective evaluation of the life of the thermal protection coating under the actual service environment, and can provide method support for material / process screening, life prediction of the thermal protection coating, and improvement of the environmental adaptability and reliability of the model during the model development stage; by introducing the concept of environmental equivalent and following the principle of environmental effect equivalence, this method realizes the correction of the temperature-humidity coupling cumulative quantity value when the thermal protection coating reaches the same performance degradation degree in the normal storage environment under the accelerated storage test environment, and then determines the equivalent test time of the accelerated test. It is applicable not only to the warehouse storage environment with small temperature and humidity fluctuations (such as the cave depot environment with temperature and humidity control measures) but also to the warehouse storage environment with fluctuating temperature and humidity trends (such as the ground warehouse without temperature and humidity control measures). Description of the Drawings

[0010] Figure 1 is a single cycle profile of the combined test spectrum for thermal protection coating life assessment (equivalent to 1 year of actual service); Figure 2 is a schematic diagram of the chord variable temperature and humidity test profile; Figure 3 is the temperature and humidity spectrum diagram of the air suspension environment (standard day); Figure 4 is the temperature and humidity spectrum diagram of the air suspension environment (hot day); Figure 5 is the ambient temperature spectrum for in-flight suspension (cold weather); Figure 6 is the vibration spectrum for in-flight suspension (takeoff and climb, patrol standby); Figure 7 is the vibration spectrum for in-flight suspension (cruise return, descent and landing); Figure 8 is the test profile for simulating the in-flight suspension environment test; Figure 9 is the curve of the retention rate of the coating adhesion; Figure 10 is the test profile for the life evaluation test of the thermal protection coating. Specific implementation manners

[0011] The following is a further detailed description through specific implementation manners: Embodiment

[0012] A method for accelerating the life evaluation of a thermal protection coating close to the service environment profile. The accelerated test load spectrum of this method is a combined test spectrum based on the storage in the warehouse and the in-flight suspension duty environment during the missile life cycle (such as Figure 1 shows the single-cycle profile of the combined test spectrum for the life evaluation of the thermal protection coating, equivalent to 1 year of actual service), and the steps are as follows. Step 1, construct a damp heat test spectrum for simulating the storage environment in the warehouse, mainly considering temperature and humidity factors. Specifically: Step 11, collect the hourly environmental factor data of temperature and relative humidity in the storage warehouse of the thermal protection coating for at least 1 natural year, and analyze its temperature and humidity characteristics and variation laws; Step 12, according to the obtained temperature and humidity characteristics and laws, determine the stress loading method for the damp heat accelerated test. If the temperature fluctuation is less than 3°C and the relative humidity fluctuation is less than 3%, then the constant damp heat test method is adopted; otherwise, the cyclic chordal variable damp heat test method with a cycle of 24 hours is adopted (such as Figure 2 shown); Step 13, determine the magnitude levels of temperature and humidity in the obtained damp heat test method: if the constant damp heat test method is adopted, the test temperature is determined to be 90°C, and the relative humidity is determined according to the average value within 1 natural year in the warehouse; if the cyclic chordal variable damp heat test method is adopted, the highest test temperature is determined to be 90°C, the lowest test temperature is determined according to the difference between the highest temperature and the lowest temperature within 1 natural year in the warehouse, and the highest relative humidity and the lowest relative humidity are consistent with the highest relative humidity and the lowest relative humidity within 1 natural year in the warehouse; Step 2, construct a combined test spectrum for simulating the in-flight suspension duty environment, including a combined test of a damp heat test for simulating the airport ground atmospheric environment and a three-in-one test of temperature, humidity and vibration for simulating the in-flight suspension environment. Specifically: Step 21, simulate the humid heat test load spectrum of the airport ground atmospheric environment, including the temperature spectrum and the relative humidity spectrum: Adopt the constant stress loading method. According to GJB899A-2009 "Reliability Qualification and Acceptance Tests", it is determined that there are three types of temperatures that the missile may encounter when on the ground at the airport, namely the temperatures of standard day, cold day, and hot day. Therefore, the temperature and relative humidity value levels in the simulated humid heat load spectrum of the airport ground atmospheric environment are mainly set for the above three typical weathers, and the test time is determined to be 40 min according to the mission profile; The temperature values corresponding to the three typical weathers are mainly determined according to GB / T 1920. Among them, the ground temperature on a standard day is 15 °C, and the ground temperatures on hot days and cold days are determined to be 45 °C on hot days and -54 °C on cold days respectively according to the risk rate of 10% of the extreme temperature of the tested product in accordance with HB5652.1; Step 22, simulate the comprehensive test load spectrum of the airborne carriage environment. The main influencing factors during the airborne carriage duty process of the missile are the airborne atmospheric environment (temperature and humidity) and flight-induced vibration. The simulated test load spectrum includes a comprehensive test spectrum of temperature spectrum, humidity spectrum, and vibration spectrum. Specifically: According to GJB899A, during the ground stage of standard day and hot day, the dew point temperature should be maintained at no less than 31 °C. By querying the dew point and moisture conversion table, it can be obtained that when the dew point temperature is 31 °C, the water content in the air is 32.1 g / m 3 , that is, during the ground stage of standard day (15 °C) and hot day (45 °C), the water content (absolute humidity) in the air should be in a state greater than 32.1 g / m 3 ; when the temperature is 45 °C, the maximum water content (saturated humidity) in the air is 65.5 g / m 3 . According to the calculation formula of relative humidity, that is, relative humidity = (absolute humidity / saturated humidity) × 100%, it can be calculated that the relative humidity corresponding to the standard day is 100%, and the relative humidity corresponding to the hot day is not less than 49%; considering the humidity control ability of the humid heat test chamber, the relative humidity corresponding to the standard day is determined to be 90%. In order to strengthen the assessment, the relative humidity corresponding to the hot day is determined to be 80%. The temperature on cold days is below 0 °C, and the humidity is not controlled; The humid heat test load spectrum of the airborne carriage environment: According to the analysis results of the corresponding airborne carriage environment and the typical flight mission profile of the carrier aircraft, determine the temperature and relative humidity load spectra corresponding to each stage during the missile's airborne carriage process, as shown in Table 1, Figures 3 to 5 as shown. Table 1 Simulated Humid Heat Test Load Spectrum of Airborne Carriage Environment Vibration test load spectrum simulating the airborne suspension environment: According to GJB899A and the typical mission profiles of the carrier aircraft, determine the vibration spectrum forms corresponding to each stage of takeoff and climb, patrol standby, cruise (return), and descent and landing. Among them, the vibration spectra in the takeoff and climb and patrol standby stages are as shown in Figure 6 , and the vibration spectra in the cruise return and descent and landing stages are as shown in Figure 7 . The corresponding vibration magnitudes are shown in Table 2. Table 2 Vibration Spectrum Magnitudes Furthermore, the test profile of the comprehensive test simulating the airborne suspension environment is as shown in Figure 8 . Step 3: According to the principle of environmental effect equivalence, determine the equivalent test time for the constant / variable humidity and heat test in the combined test profile for evaluating the life of the thermal protection coating, which is equivalent to 1 year of actual storage in the warehouse. Specifically: Step 31: Conduct comparative tests on the thermal protection coating samples under three different temperature and humidity stresses respectively. The test conditions are set according to Table 3. At least 8 - 10 detections of the coating adhesion performance should be carried out under each test condition, and the number of parallel samples for each detection should be no less than 5 pieces. Table 3 Comparative Test Conditions Step 32: Based on the periodic performance detection data of the thermal protection coating samples, calculate the performance retention rates (t i , P i ) corresponding to different test times, and construct performance degradation law models for the samples under the three test conditions respectively. Step 33: Use the established models to calculate the test times corresponding to the performance retention rates dropping to different values for the thermal protection coating under the three test conditions respectively, that is, (t 11 , t 21 , t 31 ), (t 12 , t 22 , t 32 ), (t 13 , t 23 , t 33 )…(t 1n , t 2n , t 3n ); Step 34: Use the temperature and humidity environment factor coupling model formula [1] to calculate the coupling magnitudes corresponding to the three test conditions and test times respectively, that is, (W 11 , W 21 , W 31 ), (W 12 , W 22 , W 32 ), (W13 , W 23 , W 33 )…(W 1n , W 2n , W 3n ); wherein, W is the coupled cumulative value of temperature and humidity for the selected storage duration, t is time, H(t) is the relative humidity corresponding to time t, T(t) is the absolute temperature corresponding to time t, C is a constant, W 1n represents the cumulative stress coupling quantity value at the nth detection under the first test stress condition, W 2n represents the cumulative stress coupling quantity value at the nth detection under the second test stress condition, W 3n represents the cumulative stress coupling quantity value at the nth detection under the third test stress condition; Step 35: Based on the obtained data of the coupled cumulative values of temperature and humidity under the three test conditions, establish a correlation relationship model between the coupled cumulative value and the test temperature, and calculate the corresponding coupled value of temperature and humidity (W 01 , W 02 , W 03 , …, W 0n ) in the storage environment, and then calculate a set of correction factors (W 11 / W 01 , W 12 / W 02 , …, W 1n / W 0n ) based on the environmental effect equivalence. Taking the average value can obtain the correction factor of the coupled cumulative value of temperature and humidity in the accelerated storage test environment relative to the normal storage environment; Step 36: Using the temperature and humidity environmental factor data of one natural year in the warehouse as the input, calculate the coupled cumulative value of temperature and humidity in the warehouse for one year by using the temperature and humidity coupling model formula [1]; Step 37: Calculate the corresponding coupled cumulative value of temperature and humidity in the accelerated storage test environment according to the obtained correction factor of the coupled cumulative value of temperature and humidity, and use the temperature and humidity coupling model formula [1] to inversely calculate the equivalent test time. Step 4: Based on the obtained equivalent test time and the combined test profile for evaluating the protective coating life, conduct an accelerated test in which the thermal protective coating is equivalent to the expected service life, and the number of test samples is not less than 5; after the test, compare the performance test results of the samples with the failure threshold, and evaluate whether the life of the thermal protective coating can meet the expected life according to the comparison results.

[0013] In one of the application scenarios, a silicone rubber thermal protection coating is applied to the outer casing of an air-launched missile. The missile is stored in a warehouse (with an average annual temperature of 25°C, an annual temperature difference of 10°C, and a relative humidity of 65% - 75%). The missile will perform irregular flight suspension training or duty tasks (an average of 6 times per year). Now, it is evaluated whether the lifespan of this thermal protection coating can meet 10 years. Since the temperature difference in the storage environment of this thermal protection coating is 10°C and the relative humidity difference is 10%, according to the humidity-temperature cycling test spectrum simulating the warehouse storage environment in Step 12, a cyclic sinusoidal humidity-temperature cycling test method with a cycle of 24 hours is adopted, and the temperature and humidity values in the test spectrum are determined according to Table 3 respectively.

[0014] First, accelerated tests of the thermal protection coating are carried out under three conditions: the highest temperature of 90°C, the lowest temperature of 80°C, the highest relative humidity of 75%, and the lowest relative humidity of 65% (Condition 1); the highest temperature of 80°C, the lowest temperature of 70°C, the highest relative humidity of 75%, and the lowest relative humidity of 65% (Condition 2); and the highest temperature of 70°C, the lowest temperature of 60°C, the highest relative humidity of 75%, and the lowest relative humidity of 65% (Condition 3). Each cycle is 24 hours. The test results of the adhesion retention rate are shown in Table 4 and Figure 9 as follows. Table 4 Test Results of the Adhesion Retention Rate of the Coating under Different Test Conditions

[0015] It can be seen from Figure 8 that the adhesion retention rate of this thermal protection coating shows an exponential decline trend. These data are fitted to form the performance degradation equations of the thermal protection coating under different test conditions (see Table 5), and then the humidity-temperature coupling cumulative values corresponding to different performance retention rates are calculated using Equation 1 respectively (see Table 6). Table 5 Fitting Equations of the Adhesion Retention Rate of the Coating under Different Test Conditions Table 6 Values of W Corresponding to Different Performance Retention Rates

[0016] Based on the data in Table 6, the temperature-humidity coupling cumulative amount values corresponding to the retention rates of each performance at the storage environment temperature (average temperature) are extrapolated using the exponential model, and then the conversion coefficient of the temperature-humidity coupling cumulative amount value of Test Condition 3 relative to the storage environment is obtained as 0.2828 (see Table 7). According to the temperature and humidity monitoring data of the warehouse over a natural year, the temperature-humidity coupling cumulative amount value for the whole year is calculated as 36392580.5 using the temperature-humidity coupling model in Equation 1. According to the conversion coefficient, it can be obtained that when the retention rate of the coating performance also drops to 60% under Test Condition 3, the temperature-humidity coupling cumulative amount value experienced is W = 36392580.5 × 0.2828 = 10292254.3. Substituting it into Equation 1 can be used to inversely calculate that the test of the thermal protection coating for 3.5 cycles under Test Condition 3 is approximately equivalent to 1 year of storage in the warehouse. Table 7 Conversion Coefficient of Temperature-Humidity Coupling Cumulative Amount Value of Test Condition 3 Relative to Storage Environment

[0017] Establish a test profile as Figure 10 shown (see Step 21 for the simulated temperature and humidity load spectrum of the airport ground atmospheric environment, and see Figures 3 to 8 ) for the simulated test load spectrum of the in-flight hanging environment. One cycle of the test of the thermal protection coating under this test profile is equivalent to 1 year of actual service. According to the life assessment requirements, a 10-cycle test of the thermal protection coating is carried out under this test profile. After the test is completed, the adhesion of the coating is detected, and by comparing it with the coating failure threshold, it can be judged whether the life of the thermal protection coating in the actual service environment can meet 10 years.

Claims

1. An accelerated life assessment method for a thermal protection coating close to the service environment profile, characterized in that the steps including: Step 1: Construct a damp heat test spectrum simulating the storage environment of the warehouse; Step 2: Construct a combined test spectrum simulating the environment of hanging flight and on-duty; Step 3: According to the principle of equivalent environmental effects, determine the equivalent test time for the constant / variable damp heat test in the combined test profile for evaluating the life of the thermal protection coating, which is equivalent to one year of actual warehouse storage; Step 4: Based on the obtained equivalent test time and the combined test profile for evaluating the life of the protective coating, conduct an accelerated test for the thermal protection coating equivalent to the expected service life; after the test, compare the performance test results of the samples with the failure threshold, and evaluate whether the life of the thermal protection coating can meet the expected life according to the comparison results.

2. The accelerated life assessment method of the thermal protection coating according to claim 1, wherein The steps for constructing the damp heat test spectrum simulating the storage environment of the warehouse in Step 1 include: Step 11: Collect the hourly environmental factor data of temperature and relative humidity in the storage warehouse of the thermal protection coating for at least one natural year, and analyze its temperature and humidity characteristics and variation laws; Step 12: According to the obtained temperature and humidity characteristics and laws, determine the stress loading method of the damp heat accelerated test. If the temperature fluctuation is less than 3°C and the relative humidity fluctuation is less than 3%, the constant damp heat test method is adopted; otherwise, the cyclic variable damp heat test method with a cycle of 24 hours is adopted; Step 13: Determine the magnitude levels of temperature and humidity in the obtained damp heat test method: If the constant damp heat test method is adopted, the test temperature is determined to be 90°C, and the relative humidity is determined according to the average value within one natural year of the warehouse; If the cyclic variable damp heat test method is adopted, the maximum test temperature is determined to be 90°C, the minimum test temperature is determined according to the difference between the highest temperature and the lowest temperature within one natural year of the warehouse, and the highest relative humidity and the lowest relative humidity are consistent with the highest relative humidity and the lowest relative humidity within one natural year of the warehouse.

3. The accelerated life assessment method of the thermal protection coating according to claim 1, characterized in that, The steps for constructing the combined test spectrum simulating the environment of hanging flight and on-duty in Step 2 include: Step 21: Simulate the damp heat test load spectrum of the airport ground atmosphere environment, including the temperature spectrum and the relative humidity spectrum: The temperature values corresponding to three typical weather conditions are mainly determined according to GB / T 1920. Among them, the ground temperature on a standard day is 15°C, and the ground temperatures on hot days and cold days are determined to be 45°C on hot days and -54°C on cold days respectively according to the risk rate of 10% of the extreme temperature of the tested product in accordance with HB5652.1; the relative humidity corresponding to a standard day is determined to be 80%, and when the temperature on a cold day is below 0°C, the humidity is not controlled; Step 22: Simulate the comprehensive test load spectrum of the in-air hanging flight environment, including the damp heat test load spectrum and the vibration spectrum of the in-air hanging flight environment: According to the analysis results of the hanging flight environment and the typical flight mission profile of the carrier aircraft, determine the temperature and relative humidity load spectra corresponding to each stage during the missile hanging flight process; according to the corresponding requirements in GJB899A and the typical mission profile of the carrier aircraft, determine the vibration spectrum forms corresponding to each stage of the carrier aircraft's takeoff, climb, patrol standby, cruise, and descent and landing.

4. The accelerated life assessment method of the thermal protection coating according to claim 1, wherein Step 3 specifically includes: Step 31: Conduct comparative tests on samples of the thermal protection coating under three different temperature and humidity stresses respectively. At least 8 - 10 coating adhesion performance tests should be carried out under each test condition, and the number of parallel samples for each test should be no less than 5 pieces; Step 32: Based on the periodic performance detection data of the thermal protection coating sample, calculate the performance retention rate (t i , P i ) corresponding to different test times, and respectively construct the performance degradation law models of the sample under three test conditions; Step 33: Using the established model, calculate the respective test times corresponding to different values when the performance retention rate of the thermal protection coating drops under three test conditions, namely (t 11 , t 21 , t 31 ), (t 12 , t 22 , t 32 ), (t 13 , t 23 , t 33 )…(t 1n , t 2n , t 3n ); Step 34: Using the temperature and humidity environment factor coupling model formula [1], calculate the coupling values corresponding to the three test conditions and test time, namely (W 11 , W 21 , W 31 ), (W 12 , W 22 , W 32 ), (W 13 , W 23 , W 33 )…(W 1n , W 2n , W 3n ); Where, W is the coupled value of temperature and humidity for the selected storage duration, t is time, H(t) is the relative humidity corresponding to time t, T(t) is the absolute temperature corresponding to time t, C is a constant, and W 1n represents the cumulative stress coupling quantity value at the nth detection under the first test stress condition, and W 2n represents the cumulative stress coupling quantity value at the nth detection under the second test stress condition, and W 3n represents the cumulative stress coupling quantity value at the nth detection under the third test stress condition; Step 35: Based on the obtained temperature and humidity coupling cumulative quantity value data under the three test conditions, establish a correlation relationship model between the coupling cumulative quantity value and the test temperature, calculate the corresponding temperature and humidity coupling cumulative quantity values (W 01 , W 02 , W 03 , …, W 0n ) in the storage environment, and then calculate a set of correction factors (W 11 / W 01 , W 12 / W 02 , …, W 1n / W 0n ) based on the environmental effect equivalence. Take the average value to obtain the correction factor of the temperature and humidity coupling cumulative quantity value of the accelerated storage test environment relative to the normal storage environment; Step 36: Using the temperature and humidity environmental factor data of the warehouse for one natural year as the input, calculate the temperature and humidity coupling cumulative quantity value of the warehouse for one year by using the temperature and humidity coupling model formula [1]; Step 37: Calculate the temperature and humidity coupling cumulative quantity value corresponding to the accelerated storage test environment according to the obtained correction coefficient of the temperature and humidity coupling cumulative quantity value, and use the temperature and humidity coupling model formula [1] to inversely calculate the equivalent test time.

5. The accelerated life assessment method of the thermal protection coating according to any one of claims 1-4, characterized in that: The thermal protection coating is a silicone rubber heat protection coating.

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