Equipment reliability appraisal test temperature stress model construction method

Abstract

The invention discloses an equipment reliability appraisal test temperature stress model construction method, which is characterized by comprising the following steps of: acquiring multiple types of external field measured data, and performing polynomial function fitting on the external field measured data by utilizing a least square method to obtain a temperature stress model of an equipment reliability appraisal test; and obtaining a cold-day environment temperature model of the equipment in the ram air cooling cabin in which the cold-day environment temperature changes along with the height and the Mach number, and a hot-day environment temperature model of the equipment in the ram air cooling cabin in which the hot-day environment temperature changes along with the height and the Mach number. According to the method, the calculation efficiency is improved, the manual measurement error is reduced, and the accurate temperature stress of the equipment can be obtained.

Description

Technical Field

[0001] The invention relates to the field of aviation reliability technology, and in particular to a method for constructing a temperature stress model for equipment reliability identification test. Background Art

[0002] In order to verify the reliability design level of the equipment, reliability identification tests need to be carried out during the design identification stage. The temperature stress in the reliability identification test is determined by looking up the table according to the flight speed and flight altitude of each mission stage provided by the typical mission profile, based on the hot weather ambient temperature of the equipment in the ram air-cooled cabin in Table B3.5-9 and the cold weather ambient temperature of the equipment in the ram air-cooled cabin in Table B3.5-10 in GJB 899A-2009 "Reliability Identification and Acceptance Test".

[0003] The table lookup method results in relatively large manual measurement errors. There are many equipment mission profiles, and each mission profile corresponds to many mission stages. The table lookup method for obtaining the temperatures of hot and cold days makes the workload too large, and the height and speed of some mission segments cannot be intuitively obtained in the chart. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing a temperature stress model for equipment reliability evaluation test. The present invention improves calculation efficiency, reduces manual measurement errors, and can obtain accurate temperature stress of equipment.

[0005] Technical solution. A method for constructing a temperature stress model for equipment reliability evaluation test, collecting field measured data of multiple models, using the least squares method to perform polynomial function fitting on the field measured data, and obtaining a cold weather ambient temperature model for equipment in a ram air cooled cabin that varies with altitude and Mach number, and a hot weather ambient temperature model for equipment in a ram air cooled cabin that varies with altitude and Mach number.

[0006] In the aforementioned equipment reliability identification test temperature stress model construction method, the field measured data include the hot weather ambient temperature of equipment in the ram air cooling cabin in Table B3.5-9 and the cold weather ambient temperature of equipment in the ram air cooling cabin in Table B3.5-10 in GJB899A-2009 "Reliability Identification and Acceptance Test"; the hot weather ambient temperature model is fitted based on Table B3.5-9, and the cold weather ambient temperature model is fitted based on Table B3.5-10.

[0007] In the aforementioned equipment reliability evaluation test temperature stress model construction method, the hot weather environment temperature model is as follows:

[0008] t hot (h,m)=-0.00268h 4 -0.002572h 3 m+0.02894h2 m 2 +0.1188h 3 +0.09573h 2 m

[0009] -1.079hm 2 -1.374h 2 -1.173hm+51.3m 2 -2.228h+6.76m+36.43

[0010] Where, t hot is the hot day ambient temperature of the equipment in the ram air cooling cabin; h is the altitude; m is the Mach number.

[0011] In the above-mentioned equipment reliability evaluation test temperature stress model construction method, the fitting correlation coefficient R of the hot weather environment temperature model is 2 =0.9904.

[0012] In the aforementioned equipment reliability evaluation test temperature stress model construction method, the cold weather ambient temperature model is as follows:

[0013] t cold (h,m)=0.0006958h 5 -0.0006781h 4 m+0.01987h 3 m 2 -0.03798h 4 +0.008979h 3 m

[0014] -0.5103h 2 m 2 +0.7821h 3 +0.08965h 2 m+1.596hm 2 -7.3h 2 +0.6213hm+46.97m 2 +23.85h-9.735m-47.57

[0015] Where, t cold is the cold weather ambient temperature of the equipment in the ram air cooling cabin; h is the altitude; m is the Mach number.

[0016] In the aforementioned equipment reliability evaluation test temperature stress model construction method, the fitting correlation coefficient R of the cold weather ambient temperature model is 2 =0.9728.

[0017] In the aforementioned method for constructing the temperature stress model of the equipment reliability identification test, when the actual flight Mach number m≤0.4, m=0.4 is taken; when the actual flight Mach number m≥1.0, m=1.0 is taken.

[0018] In the aforementioned equipment reliability evaluation test temperature stress model construction method, when the altitude h is 10 km and the Mach number m is 0.7, the ambient temperature of the equipment in the ram air cooling cabin is -46.27°C in cold weather and -8.56°C in hot weather.

[0019] Beneficial effects: The present invention fits the hot-weather ambient temperature of equipment in the ram air-cooled cabin in Table B3.5-9 and the cold-weather ambient temperature of equipment in the ram air-cooled cabin in Table B3.5-10 in GJB 899A-2009 "Reliability Appraisal and Acceptance Test" into a corresponding calculation model using the least squares method. The temperature stress of each mission segment can be directly calculated by inputting the height and speed of the mission segment, thereby reducing manual measurement errors, improving calculation efficiency, and obtaining accurate temperature stress of the equipment, providing support for compiling equipment reliability appraisal test profiles. DETAILED DESCRIPTION

[0020] Embodiment 1. A method for constructing a temperature stress model for equipment reliability identification test is obtained by statistically analyzing field measured data of multiple models to obtain the relationship between the hot and cold weather ambient temperatures of equipment in a ram air-cooled cabin and the altitude and Mach number, see Table B3.5-9 Hot weather ambient temperatures of equipment in a ram air-cooled cabin and Table B3.5-10 Cold weather ambient temperatures of equipment in a ram air-cooled cabin in GJB 899A-2009 "Reliability Identification and Acceptance Test", and see Table 1 and Table 2 for specific contents.

[0021] Table 1 Hot day ambient temperature of equipment in ram air cooling cabin

[0022]

[0023] Table 2 Cold weather ambient temperature of equipment in ram air cooling cabin

[0024]

[0025] The specific technical solutions are as follows:

[0026] 1. Using the least squares method, the data in Table 1 are fitted into a polynomial function to determine the hot day ambient temperature t of the equipment in the ram air cooling cabin. hot Quantitative relationship with Mach number m and altitude h.

[0027] Adjust the highest exponent of Mach number m and height h, fit different polynomial functions, and fit the correlation coefficient R 2 There are 4 results above 0.99, which are:

[0028] (a) The highest index of h is 5, and the highest index of m is 3;

[0029] (b) The highest index of h is 5, and the highest index of m is 2;

[0030] (c) The highest index of h is 4, and the highest index of m is 3;

[0031] (d) The highest index of h is 4, and the highest index of m is 2;

[0032] Among them, the one with the smallest sum of terms is h, with the highest index being 4, and m with the highest index being 2. The polynomial function is shown in formula (1), which can be used to represent the hot day ambient temperature t of the equipment in the ram air cooling cabin. hot The relationship between Mach number m and altitude h is:

[0033] t hot (h,m)=-0.00268h 4 -0.002572h 3 m+0.02894h 2 m 2 +0.1188h 3 +0.09573h 2 m-1.079h

[0034] m 2 -1.374h 2 -1.173hm+51.3m 2 -2.228h+6.76m+36.43, R 2 = 0.9904 (1)

[0035] Where, t hot ——Ambient temperature of equipment in the ram air cooling cabin on hot days, in °C;

[0036] h——height, in km;

[0037] m——Mach number, dimensionless. When the actual flight Mach number m≤0.4, take m=0.4; when the actual flight Mach number m≥1.0, take m=1.0.

[0038] Second, adjust the highest exponent of Mach number m and altitude h, and fit different polynomial functions. For example, when the altitude h is 10km and the Mach number m is 0.7, the above function can be used to obtain the hot day ambient temperature of the equipment in the ram air cooling cabin.

[0039] t hot =-0.00268×10 4 -0.002572×10 3 ×0.7+0.02894×102 ×0.7 2 +0.1188×10 3 +0.09573

[0040] ×10 2 ×0.7-1.079×10×0.7 2 -1.374×10 2 -1.173×10×0.7+51.3×0.7 2 -2.228×10+6.76×0.7+36.43=-8.56℃.

[0041] 3. Using the least squares method, the data in Table 2 are fitted into a polynomial function to determine the cold-weather ambient temperature t of the equipment in the ram air-cooled cabin. cold Quantitative relationship with Mach number m and altitude h.

[0042] Adjust the highest exponent of Mach number m and height h, fit different polynomial functions, and fit the correlation coefficient R 2 There are 2 above 0.97, which are:

[0043] (a) The highest index of h is 5, and the highest index of m is 3;

[0044] (b) The highest index of h is 5, and the highest index of m is 2;

[0045] The latter's fitting correlation coefficient R 2 It is 0.001 less than the former, but has fewer items, and is suitable for expressing the cold weather ambient temperature t of the equipment in the ram air cooling cabin. cold The relationship between the height h and the Mach number m is shown in formula (2):

[0046] t cold (h,m)=0.0006958h 5 -0.0006781h 4 m+0.01987h 3 m 2 -0.03798h 4 +0.008979h 3 m

[0047] -0.5103h 2 m 2 +0.7821h 3 +0.08965h 2 m+1.596hm 2 -7.3h 2 +0.6213hm+46.97m 2 +23.85h-9.

[0048] 735m-47.57,R 2 =0.9728 (2)

[0049] Where, t cold ——Cold weather ambient temperature of equipment in the ram air cooling cabin, unit: °C;

[0050] h——height, in km;

[0051] m——Mach number, dimensionless. When the actual flight Mach number m≤0.4, take m=0.4; when the actual flight Mach number m≥1.0, take m=1.0.

[0052] 4. Adjust the highest exponent of Mach number m and altitude h, and fit different polynomial functions. For example, when the altitude h is 10km and the Mach number m is 0.7, the above function can be used to obtain the cold weather ambient temperature of the equipment in the ram air cooling cabin.

[0053] t cold =0.0006958×10 5 -0.0006781×10 4 ×0.7+0.01987×10 3 ×0.7 2 -0.03798×10 4 +0.00

[0054] 8979×10 3 ×0.7-0.5103×10 2 ×0.7 2 +0.7821×10 3 +0.08965×10 2 ×0.7+1.596×10×0.7 2 -7.3×10 2 +0.6213×10×0.7+46.97×0.7 2 +23.85×10-9.735×0.7-47.57=-46.27°C.

Claims

1. A method for constructing a temperature stress model for equipment reliability evaluation test, characterized in that: Field measured data of multiple models were collected, and polynomial functions were fitted to the field measured data using the least squares method to obtain a cold-weather ambient temperature model in which the cold-weather ambient temperature of equipment in the ram air-cooled cabin changes with altitude and Mach number, and a hot-weather ambient temperature model in which the hot-weather ambient temperature of equipment in the ram air-cooled cabin changes with altitude and Mach number.

2. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 1, characterized in that: The field measured data include the hot weather ambient temperature of equipment in the ram air cooling cabin in Table B3.5-9 and the cold weather ambient temperature of equipment in the ram air cooling cabin in Table B3.5-10 in GJB 899A-2009 "Reliability Appraisal and Acceptance Test"; the hot weather ambient temperature model is fitted based on Table B3.5-9, and the cold weather ambient temperature model is fitted based on Table B3.5-10.

3. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 1, characterized in that: The hot day ambient temperature model is as follows: t hot (h,m)=-0.00268h 4 -0.002572h 3 m+0.02894h 2 m 2 +0.1188h 3 +0.09573h 2 m <h2 style=";text-align:left;direction:ltr">-1.079hm<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -1.374h<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -1.173hm+51.3m<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -2.228h+6.76m+36.43 Where, t hot is the hot day ambient temperature of the equipment in the ram air cooling cabin; h is the altitude; m is the Mach number.

4. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 3, characterized in that: Fitting correlation coefficient R of hot weather ambient temperature model 2 =0.9904.

5. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 1, characterized in that: The cold weather ambient temperature model is as follows: t cold (h,m)=0.0006958h 5 -0.0006781h 4 m+0.01987h 3 m 2 -0.03798h 4 +0.008979h 3 m <h2 style=";text-align:left;direction:ltr">-0.5103h<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> m<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +0.7821h<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +0.08965h<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> m+1.596hm<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -7.3h<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +0.6213hm+46.97m<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +23.85h-9.735m-47.57 Where, t cold is the cold weather ambient temperature of the equipment in the ram air cooling cabin; h is the altitude; m is the Mach number.

6. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 5, characterized in that: Fitting correlation coefficient R of cold weather ambient temperature model 2 =0.9728.

7. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 3 or 5, characterized in that: When the actual flight Mach number m≤0.4, take m=0.4; when the actual flight Mach number m≥1.0, take m=1.

0.

8. The method for constructing a temperature stress model for equipment reliability evaluation test according to claim 3 or 5, characterized in that: When the altitude h is 10km and the Mach number m is 0.7, the ambient temperature of the equipment in the ram air-cooled cabin is -46.27℃ in cold weather and -8.56℃ in hot weather.

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