Aero-engine static pressure-bearing part pressure containment test design method

Abstract

The invention relates to the technical field of aero-engines, and discloses an aero-engine static pressure-bearing part pressure containment test design method, which comprises the following steps: under a limited pressure load, determining that a first pressure containment margin is greater than a first set value; under the ultimate pressure load, it is determined that the second pressure containing margin is larger than a second set value; under the limited load, determining a first equivalent load of the pressure containment test of the static pressure-bearing part on the basis of ensuring that the yield strength margins of the static pressure-bearing part in the test state and the working state are equivalent; and under the limit load, determining a second equivalent load of the pressure containment test of the static pressure-bearing part on the basis of ensuring that the limit strength margins of the static pressure-bearing part in the test state and the working state are equivalent. By limiting the first pressure containing margin and the second pressure containing margin, the machine body damage and casualty risks caused by static pressure bearing piece damage are reduced; by introducing the first equivalent load and the second equivalent load, it is ensured that the static pressure-bearing part is tested in place.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engines, and in particular to a pressure containment test design method for static pressure-bearing parts of an aero-engine. Background Art

[0002] In Article 33.64 of the "Regulations on Airworthiness of Aircraft Engines", it is recorded about "Engine Static Pressure Parts": Provisions are made for the strength of engine stator parts that bear large gas or liquid pressure loads, requiring that engine stator parts cannot exhibit permanent deformation exceeding the use limit when subjected to limited pressure; stator parts cannot rupture or explode when subjected to ultimate pressure; stator parts that bear pressure are also called static pressure parts.

[0003] Compared to damage to stator components caused by mechanical and thermal loads, damage to stator components caused by aerodynamic pressure loads is more dangerous and sudden. Generally speaking, failure of stator components caused by mechanical and thermal loads typically begins locally at a weak location, such as local plastic deformation or failure of a localized connection structure. To address these mechanical and thermal loads, stator component structural design can incorporate certain redundancies to reduce the risk of sudden, large-scale failure.

[0004] Current strength design for static pressure-bearing components on aircraft engines follows the same strength assessment criteria as for conventional components. Stress analysis is typically required to ensure that the component does not undergo plastic deformation under limiting loads and does not fail under ultimate loads. This analysis primarily considers internal and external pressure loads on the casing, aerodynamic loads on the mounting edge, and inertial loads. Strength design based on stress analysis primarily involves the following three methods.

[0005] Method 1: Through material yield strength σ 0.2 Evaluate the deformation of statically loaded components under limiting loads and define the material yield strength σ 0.2 and limiting workload σ work-限制 The ratio is n 0.2 , as shown in formula (1).

[0006]

[0007] When n 0.2 When >1.0, it is considered that the static pressure-bearing parts do not deform under the action of the limit load.

[0008] Method 2: Through the material ultimate strength σ b Evaluate the integrity of statically loaded components under ultimate loads and define the ultimate material strength σ b and σ work-极限 The ratio is n b , as shown in formula (2).

[0009]

[0010] When n b When >1.0, it is considered that the static pressure-bearing parts will not be damaged under the action of the ultimate load.

[0011] Method 3: Apply equivalent correction coefficient method to the test load, specifically: define F work is the workload, define F test is the test load, test load F test At working load F work Based on , it is obtained by considering material correction and temperature correction, as shown in formula (3).

[0012] F test =K 材料 ×K 温度 ×F work (3)

[0013] Among them, K 材料 is the material correction factor, K 温度 is the temperature correction coefficient, material correction coefficient K 材料 and temperature correction factor K 温度 Experience values can be used.

[0014] When static components such as the casing of an aircraft engine are subjected to internal pressure and reach their limit, failure often occurs suddenly, with the failure mode being a complete explosion. The resulting casing fragments, under the action of high-pressure gases, form high-energy fragments, which can easily lead to high-temperature gas leaks. High-temperature gas leaks can easily burn fuel and lubricating oil lines, leading to external fires in the aircraft engine, with serious consequences for the entire aircraft and the personnel within. Therefore, it is necessary to ensure that the static pressure-bearing components of aircraft engines have sufficient safety margins through strength design and test verification.

[0015] The above existing strength design for stress analysis is applicable to the strength design of ordinary components, and does not consider the harmful consequences of damage to the body and casualties caused by the damage of static pressure-bearing parts; the correction coefficient method is used to adjust the working load F work Correct and convert to test load F test Since the loading scheme and adapter ends used in the test process are different from the actual working conditions of the aircraft engine, the stress state of the test part is different from the target state, and there is a risk of inadequate assessment. Summary of the Invention

[0016] In view of this, the present invention provides a method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine, so as to solve the problem that the existing strength design based on stress analysis is applicable to the strength design of ordinary components, and does not consider the hazardous consequences of damage to the aircraft body and casualties caused by the damage of static pressure-bearing parts; a correction coefficient method is used to correct and convert the working load into a test load. Since the loading scheme and the adapter end in the test process are different from the actual working state of the aircraft engine, the stress state of the test part is different from the target state, and there is a risk of inadequate assessment.

[0017] The present invention provides a method for designing a pressure containment test for static pressure-bearing parts of an aero-engine, comprising:

[0018] Under the action of the limiting pressure load, determining a first pressure tolerance margin C, and requiring the first pressure tolerance margin C to be greater than a first set value;

[0019] Under the action of the ultimate pressure load, a second pressure tolerance margin W is determined, and the second pressure tolerance margin W is required to be greater than a second set value;

[0020] Under the condition of limited load, the first equivalent load P of the static pressure-bearing part pressure containment test of the static pressure-bearing part is determined by iterative conversion based on the basis of ensuring that the yield strength margin of the test state and the working state of the static pressure-bearing part of the aircraft engine is equivalent. test-限制 ;

[0021] Under the condition of ultimate load, the second equivalent load P of the static pressure-bearing parts pressure containment test of the static pressure-bearing parts is determined by iterative conversion based on the basis of ensuring that the ultimate strength margin of the test state and the working state of the static pressure-bearing parts of the aircraft engine are equivalent. test-极限 . Beneficial effect: The present application adopts the above technical solution, by limiting the first pressure containment margin C and the second pressure containment margin W, introducing a certain pressure containment capacity reserve, and considering the pressure containment capacity of the static pressure-bearing parts separately in the design, to ensure that the static pressure-bearing parts have sufficient pressure containment margin, and reduce the risk of damage to the body and casualties caused by the damage of the static pressure-bearing parts; and, by introducing the first equivalent load and the second equivalent load, it is ensured that the static pressure-bearing parts of the aircraft engine have a considerable strength reserve margin in both the working state and the test state, the test load is more accurate, and the test assessment of the static pressure-bearing parts of the aircraft engine is in place. The technical solution of the present application ensures that the static pressure-bearing parts of the aircraft engine have sufficient safety margin.

[0022] Optionally, determining the first pressure containment margin C includes:

[0023] Determine the maximum limiting pressure load P 限制 ;

[0024] Determine the maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 ;

[0025] The first pressure tolerance margin C is calculated according to formula (4);

[0026]

[0027] Determining the second pressure containment margin W includes:

[0028] Determine the maximum ultimate pressure load P 极限 ;

[0029] Determine the maximum pressure load P that the static pressure-bearing part can withstand without failure b ;

[0030] The second pressure tolerance margin W is calculated according to formula (5);

[0031]

[0032] Optionally, determine the maximum limiting pressure load P 限制 include:

[0033] For static pressure-bearing parts of aircraft engines with a certain structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined as the maximum working pressure in accordance with the requirements of airworthiness regulations; the pressure load and the corresponding temperature load at the normal working pressure state shall be determined as the normal working pressure in accordance with the requirements of airworthiness regulations;

[0034] Calculate 1.1 times the maximum working pressure as the first load;

[0035] Calculate 1.33 times the normal working pressure as the second load;

[0036] A load 35 kPa greater than the normal operating pressure is used as the third load;

[0037] Select the minimum value among the first load, the second load and the third load as the maximum limit pressure load P 限制 ;

[0038] Determine the maximum ultimate pressure load P 极限 include:

[0039] For static pressure-bearing parts of aircraft engines with a certain structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined as the maximum working pressure in accordance with the requirements of airworthiness regulations; the pressure load and the corresponding temperature load at the maximum possible pressure state shall be determined as the maximum possible pressure in accordance with the requirements of airworthiness regulations;

[0040] Calculate 1.15 times the maximum possible pressure as the fourth load;

[0041] Calculate 1.5 times the maximum working pressure as the fifth load;

[0042] A load greater than the maximum possible pressure of 35 kPa is used as the sixth load;

[0043] The minimum value among the fourth load, the fifth load and the sixth load is selected as the maximum limit pressure load P 极限 .

[0044] Optionally, determine the maximum pressure load P that the static pressure-bearing part can withstand without permanent deformation. 0.2 include:

[0045] The initial dimension from the left flange to the right flange of the static pressure-bearing part is defined as L0, and the radius of the static pressure-bearing part is defined as R0. After the static pressure-bearing part is subjected to the limited pressure load, the dimension from the left flange to the right flange is L1, and the radius of the static pressure-bearing part is R1. The dimensional change rate ΔL of the left and right flanges under load is calculated according to formula (6), and the dimensional change rate ΔR of the radius is calculated according to formula (7).

[0046]

[0047]

[0048] Determine P by elastic-plastic stress-strain iterative analysis 0.2 .

[0049] Alternatively, P is determined by elastic-plastic stress-strain iterative analysis. 0.2 include:

[0050] Set the load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n , when the applied pressure load P 0.2-n When the size change rate ΔL of the left and right flanges or the radius size change rate ΔR of the static pressure-bearing parts reaches 0.2%, the pressure load P is determined. 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

[0051] Optionally, determine the maximum pressure load P that the static pressure-bearing part can withstand without permanent deformation. 0.2 include:

[0052] Defined in the maximum limit pressure load P 限制 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 限制 , define the elongation of the static pressure-bearing material as A, set the load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n , when the applied pressure load P 0.2-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 限制When it reaches half of A, the pressure load P is determined 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

[0053] Optionally, determine the maximum pressure load P that the static pressure-bearing member can withstand without damage. b include:

[0054] Defined in the maximum ultimate pressure load P 极限 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 极限 , define the elongation of the static pressure-bearing material as A, set the load step P b-0 ,P b-1 ,...,P b-n , when the applied pressure load P b-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 极限 When A is reached, the pressure load P is determined b-n The maximum pressure load P that a static pressure-bearing part can withstand without damage b .

[0055] Optionally, in determining P 0.2 and P b When considering the tolerance factor, the design range of the wall thickness of the static pressure-bearing parts is [d min ,d max ], all in accordance with d max Elastic-plastic analysis is carried out based on the minimum stress-strain curve of the material of the static pressure-bearing parts.

[0056] Optionally, according to formula (8), the yield strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is guaranteed to be equivalent;

[0057] n 0.2-work =n 0.2-test (8)

[0058] Among them, n 0.2-work The yield strength reserve of the pressure containment test part of the static pressure-bearing parts of the aircraft engine in working condition, n 0.2-test It is the yield strength reserve for the pressure containment assessment of static pressure-bearing parts in the test state of aircraft engines;

[0059] Determine n 0.2-work include:

[0060] Define the pressure load of static pressure-bearing parts of the aircraft engine in working state under the limit load condition as P work-限制 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-限制 , the maximum equivalent stress of the working state assessment part is σ work-限制； In Twork-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2work-限制 , the yield strength reserve of the pressure tolerance assessment part of the static pressure-bearing parts of the aircraft engine in working condition n 0.2-work Calculate according to formula (9);

[0061]

[0062] Determine n 0.2-test include:

[0063] Define the pressure load of static pressure-bearing parts of aircraft engine test state under limit load conditions as P test-限制 , the test state temperature is T test-限制 , the maximum equivalent stress of the test state assessment part is σ test-限制 ; in T test-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2test-限制 , the yield strength reserve of the pressure containment assessment part of the static pressure-bearing parts of the aero-engine test state n 0.2-test Calculate according to formula (10);

[0064]

[0065] Optionally, according to formula (11), the ultimate strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is guaranteed to be equivalent;

[0066] n b-work =n b-test (11)

[0067] Among them, n b-work The ultimate strength reserve of the static pressure-bearing parts under the working state of the aircraft engine, n b-test It is the ultimate strength reserve for the pressure containment assessment of static pressure-bearing parts in the test state of aircraft engines;

[0068] Determine n b-work include:

[0069] Define the pressure load of static pressure-bearing parts of the aircraft engine in working state under the limit load condition as P work-极限 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-极限 , the maximum equivalent stress of the working state assessment part is σ work-极限 ; in T work-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ bwork-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aircraft engine in working condition, pressure tolerance assessment part b-work Calculate according to formula (12);

[0070]

[0071] Determine n b-test include:·

[0072] Define the pressure load of static pressure-bearing parts of aircraft engine test state under the ultimate load condition as P test-极限 , the test state temperature is T test-极限 , the maximum equivalent stress of the test state assessment part is σ test-极限 ; in T test-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ btest-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aero-engine test state n b-test Calculate according to formula (13);

[0073] BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0075] Figure 1 A schematic diagram of a partial cross-sectional structure of a static pressure-bearing component of an aircraft engine provided in an embodiment of the present invention;

[0076] Figure 2 The present invention provides a flow chart of a method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine. DETAILED DESCRIPTION

[0077] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0078] like Figures 1 to 2 A specific implementation of the pressure containment test design method for static pressure-bearing parts of an aircraft engine shown includes the following steps:

[0079] S1. Under the action of a limited pressure load, determine a first pressure tolerance margin C, and require that the first pressure tolerance margin C be greater than a first set value, wherein the first set value is 1.25.

[0080] S2. Under the action of the ultimate pressure load, determine a second pressure tolerance margin W, and require that the second pressure tolerance margin W be greater than a second set value, wherein the second set value is 1.25.

[0081] S3. Under the condition of limited load, based on the guarantee that the yield strength margin of the static pressure-bearing parts of the aircraft engine in the test state and the working state is equivalent, the first equivalent load P of the static pressure-bearing parts pressure containment test is determined by iterative conversion. test-限制 Among them, the iterative conversion is to determine the first equivalent load P by step-by-step trial calculation. test-限制 , to ensure that the yield strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is equivalent.

[0082] S4. Under the condition of ultimate load, based on the basis of ensuring that the ultimate strength margin of the static pressure-bearing parts of the aircraft engine in the test state and the working state is equivalent, the second equivalent load P of the static pressure-bearing parts pressure containment test is determined by iterative conversion. test-极限 Among them, the iterative conversion is to determine the second equivalent load P by step-by-step trial calculation. test-极限 , to ensure that the ultimate strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is equivalent.

[0083] Specifically, determining the first pressure tolerance margin C includes the following steps:

[0084] S11. Determine the maximum limit pressure load P 限制 ;

[0085] S12. Determine the maximum pressure load P that the static pressure-bearing part can withstand without permanent deformation. 0.2 ;

[0086] S13, the first pressure tolerance margin C is calculated according to formula (4);

[0087]

[0088] Specifically, determining the second pressure tolerance margin W includes the following steps:

[0089] S21. Determine the maximum limit pressure load P 极限 ;

[0090] S22. Determine the maximum pressure load P that the static pressure-bearing parts can withstand without damage. b ;

[0091] S23, the second pressure tolerance margin W is calculated according to formula (5);

[0092]

[0093] Specifically, determine the maximum limiting pressure load P限制 The following steps are involved:

[0094] S111. For static pressure-bearing parts of aircraft engines with a defined structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined in accordance with the requirements of airworthiness regulations as the maximum working pressure;

[0095] S112. Determine the pressure load and the corresponding temperature load under normal operating pressure as the normal operating pressure in accordance with airworthiness regulations;

[0096] S113. Calculate 1.1 times the maximum working pressure as the first load;

[0097] S114. Calculate 1.33 times the normal operating pressure as the second load;

[0098] S115. Set a load greater than the normal operating pressure by 35 kPa as the third load;

[0099] S116, select the minimum value among the first load, the second load and the third load as the maximum limit pressure load P 限制 .

[0100] Specifically, determine the maximum ultimate pressure load P 极限 The following steps are involved:

[0101] S211. For static pressure-bearing parts of aircraft engines with a defined structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined as the maximum working pressure in accordance with the requirements of airworthiness regulations;

[0102] S212. Determine the pressure load and the corresponding temperature load at the maximum possible pressure state as the maximum possible pressure in accordance with airworthiness regulations;

[0103] S213. Calculate 1.15 times the maximum possible pressure as the fourth load;

[0104] S214. Calculate 1.5 times the maximum working pressure as the fifth load;

[0105] S215, setting a load greater than the maximum possible pressure of 35 kPa as the sixth load;

[0106] S216, select the minimum value among the fourth load, the fifth load and the sixth load as the maximum limit pressure load P 极限 .

[0107] Specifically, determine the maximum pressure load P that the static pressure-bearing part can withstand without permanent deformation. 0.2 The following steps are involved:

[0108] S121, such as Figure 1As shown in the figure, the initial dimension from the left flange to the right flange of the static pressure-bearing part is defined as L0, and the radius of the static pressure-bearing part is defined as R0; after the static pressure-bearing part is subjected to the limited pressure load, the dimension from the left flange to the right flange is L1, and the radius of the static pressure-bearing part is R1; the dimensional change rate ΔL of the left and right flanges under load is calculated according to formula (6), and the dimensional change rate ΔR of the radius is calculated according to formula (7);

[0109]

[0110] S122, determine P by elastic-plastic stress-strain iterative analysis 0.2 .

[0111] Specifically, P is determined by elastic-plastic stress-strain iterative analysis. 0.2 The following steps are involved:

[0112] S1221, set load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n ;

[0113] S1222, when the applied pressure load P 0.2-n When the size change rate ΔL of the left and right flanges or the radius size change rate ΔR of the static pressure-bearing parts reaches 0.2%, the pressure load P is determined. 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

[0114] Specifically, or determine the maximum compressive load P that the static pressure-bearing part can withstand without permanent deformation 0.2 The following steps are involved:

[0115] S123, defined as the maximum limit pressure load P 限制 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 限制 , define the elongation of the static pressure-bearing material as A, set the load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n ;

[0116] S124, when the applied pressure load P 0.2-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 限制 When it reaches half of A, the pressure load P is determined 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

[0117] Specifically, determine the maximum pressure load P that the static pressure-bearing part can withstand without damage. b The following steps are involved:

[0118] S221, defined as the maximum ultimate pressure load P 极限 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 极限 , define the elongation of the static pressure-bearing material as A, set the load step P b-0 ,P b-1 ,...,P b-n ;

[0119] S222, when the applied pressure load P b-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 极限 When A is reached, the pressure load P is determined b-n The maximum pressure load P that a static pressure-bearing part can withstand without damage b .

[0120] Furthermore, in determining P 0.2 and P b When considering the tolerance factor, the design range of the wall thickness of the static pressure-bearing parts is [d min ,d max ], all in accordance with d max Elastic-plastic analysis is carried out based on the minimum stress-strain curve of the material of the static pressure-bearing parts.

[0121] Specifically, according to formula (8), the yield strength margin of the static pressure-bearing parts of the aero-engine under test state and working state is guaranteed to be equivalent;

[0122] n 0.2-work =n 0.2-test (8)

[0123] Among them, n 0.2-work The yield strength reserve of the pressure containment test part of the static pressure-bearing parts of the aircraft engine in working condition, n 0.2-test It is the yield strength reserve for the pressure containment assessment of static pressure-bearing parts in the test state of aircraft engines;

[0124] Specifically, determine n 0.2-work The following steps are involved:

[0125] Define the pressure load of static pressure-bearing parts of the aircraft engine in working state under the limit load condition as P work-限制 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-限制 , the maximum equivalent stress of the working state assessment part is σ work-限制 ; in T work-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2work-限制 , the yield strength reserve of the pressure tolerance assessment part of the static pressure-bearing parts of the aircraft engine in working condition n 0.2-work Calculate according to formula (9);

[0126]

[0127] Specifically, determine n 0.2-test The following steps are involved:

[0128] Define the pressure load of static pressure-bearing parts of aircraft engine test state under limit load conditions as P test-限制 , the test state temperature is T test-限制 , the maximum equivalent stress of the test state assessment part is σ test-限制 ; in T test-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2test-限制 , the yield strength reserve of the pressure containment assessment part of the static pressure-bearing parts of the aero-engine test state n 0.2-test Calculate according to formula (10);

[0129]

[0130] Specifically, according to formula (11), the ultimate strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is guaranteed to be equivalent;

[0131] n b-work =n b-test (11)

[0132] Among them, n b-work The ultimate strength reserve of the static pressure-bearing parts under the working state of the aircraft engine, n b-test It is the ultimate strength reserve for the pressure containment assessment parts of static pressure-bearing parts in the test state of aircraft engines.

[0133] Specifically, determine n b-work The following steps are involved:

[0134] Define the pressure load of static pressure-bearing parts of the aircraft engine in working state under the limit load condition as P work-极限 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-极限 , the maximum equivalent stress of the working state assessment part is σ work-极限 ; in T work-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ bwork-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aircraft engine in working condition, pressure tolerance assessment part b-work Calculate according to formula (12);

[0135]

[0136] Specifically, determine n b-test The following steps are involved:

[0137] Define the pressure load of static pressure-bearing parts of aircraft engine test state under the ultimate load condition as P test-极限 , the test state temperature is T test-极限 , the maximum equivalent stress of the test state assessment part is σ test-极限 ; in T test-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ btest-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aero-engine test state n b-test Calculate according to formula (13);

[0138]

[0139] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine, characterized in that: include: Under the action of the limiting pressure load, determining a first pressure tolerance margin C, and requiring the first pressure tolerance margin C to be greater than a first set value; Under the action of the ultimate pressure load, a second pressure tolerance margin W is determined, and the second pressure tolerance margin W is required to be greater than a second set value; Under the condition of limited load, based on the guarantee that the yield strength margin of the static pressure-bearing parts of the aircraft engine in the test state and the working state is equivalent, the first equivalent load P of the static pressure-bearing parts pressure containment test is determined by iterative conversion. test-限制 ; Under the condition of ultimate load, the second equivalent load P of the static pressure-bearing parts pressure containment test of the static pressure-bearing parts is determined by iterative conversion based on the basis of ensuring that the ultimate strength margin of the test state and the working state of the static pressure-bearing parts of the aircraft engine are equivalent. test-极限 .

2. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 1, characterized in that: Determining the first pressure containment margin C includes: Determine the maximum limiting pressure load P 限制 ; Determine the maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 ; The first pressure tolerance margin C is calculated according to formula (4); C=P 0.2 / P 限制 (4); Determining the second pressure containment margin W includes: Determine the maximum ultimate pressure load P 极限 ; Determine the maximum pressure load P that the static pressure-bearing part can withstand without failure b ; The second pressure tolerance margin W is calculated according to formula (5); W=P b / P 极限 (5)。 3. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 2, characterized in that: Determine the maximum limiting pressure load P 限制 include: For static pressure-bearing parts of aircraft engines with a certain structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined as the maximum working pressure in accordance with the requirements of airworthiness regulations; the pressure load and the corresponding temperature load at the normal working pressure state shall be determined as the normal working pressure in accordance with the requirements of airworthiness regulations; Calculate 1.1 times the maximum working pressure as the first load; Calculate 1.33 times the normal working pressure as the second load; A load 35 kPa greater than the normal operating pressure is used as the third load; Select the minimum value among the first load, the second load and the third load as the maximum limit pressure load P 限制 ; Determine the maximum ultimate pressure load P 极限 include: For static pressure-bearing parts of aircraft engines with a certain structure, the pressure load and the corresponding temperature load at the maximum working pressure state shall be determined as the maximum working pressure in accordance with the requirements of airworthiness regulations; the pressure load and the corresponding temperature load at the maximum possible pressure state shall be determined as the maximum possible pressure in accordance with the requirements of airworthiness regulations; Calculate 1.15 times the maximum possible pressure as the fourth load; Calculate 1.5 times the maximum working pressure as the fifth load; A load greater than the maximum possible pressure of 35 kPa is used as the sixth load; The minimum value among the fourth load, the fifth load and the sixth load is selected as the maximum limit pressure load P 极限 .

4. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 2, characterized in that: Determine the maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 include: The initial dimension from the left flange to the right flange of the static pressure-bearing part is defined as L0, and the radius of the static pressure-bearing part is defined as R0. After the static pressure-bearing part is subjected to the limited pressure load, the dimension from the left flange to the right flange is L1, and the radius of the static pressure-bearing part is R1. The dimensional change rate ΔL of the left and right flanges under load is calculated according to formula (6), and the dimensional change rate ΔR of the radius is calculated according to formula (7). ΔL=L0 / L1 (6) ΔR=R0 / R1 (7) Determine P by elastic-plastic stress-strain iterative analysis 0.2 .

5. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 4, characterized in that: Determine P by elastic-plastic stress-strain iterative analysis 0.2 include: Set the load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n , when the applied pressure load P 0.2-n When the size change rate ΔL of the left and right flanges or the radius size change rate ΔR of the static pressure-bearing parts reaches 0.2%, the pressure load P is determined. 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

6. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 2, characterized in that: Determine the maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 include: Defined in the maximum limit pressure load P 限制 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 限制 , define the elongation of the static pressure-bearing material as A, set the load step P 0.2-0 ,P 0.2-1 ,...,P 0.2-n , when the applied pressure load P 0.2-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 限制 When it reaches half of A, the pressure load P is determined 0.2-n The maximum pressure load P that a static pressure-bearing part can withstand without permanent deformation 0.2 .

7. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to claim 2, characterized in that: Determine the maximum pressure load P that the static pressure-bearing part can withstand without failure b include: Defined in the maximum ultimate pressure load P 极限 The local maximum equivalent plastic strain of the static pressure-bearing member under the action is ε 极限 , define the elongation of the static pressure-bearing material as A, set the load step P b-0 ,P b-1 ,...,P b-n , when the applied pressure load P b-n The local maximum equivalent plastic strain ε of the static pressure-bearing component 极限 When A is reached, the pressure load P is determined b-n The maximum pressure load P that a static pressure-bearing part can withstand without damage b .

8. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to any one of claims 2 to 7, characterized in that: In determining P 0.2 and P b When considering the tolerance factor, the design range of the wall thickness of the static pressure-bearing parts is [d min ,d max ], all in accordance with d max Elastic-plastic analysis is carried out based on the minimum stress-strain curve of the material of the static pressure-bearing parts.

9. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to any one of claims 1 to 7, characterized in that: According to formula (8), the yield strength margin of the static pressure-bearing parts of the aero-engine under test state and working state is guaranteed to be equivalent; n 0.2-work =n 0.2-test (8) Among them, n 0.2-work The yield strength reserve of the pressure containment test part of the static pressure-bearing parts of the aircraft engine in working condition, n 0.2-test It is the yield strength reserve for the pressure containment assessment of static pressure-bearing parts in the test state of aircraft engines; Determine n 0.2-work include: Define the pressure load of static pressure-bearing parts of the aircraft engine in working state under the limit load condition as P work-限制 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-限制 , the maximum equivalent stress of the working state assessment part is σ work-限制； In T work-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2work-限制 , the yield strength reserve of the pressure tolerance assessment part of the static pressure-bearing parts of the aircraft engine in working condition n 0.2-work Calculate according to formula (9); n 0.2-work =s 0.2work-限制 / s work-限制 (9) Determine n 0.2-test include: Define the pressure load of static pressure-bearing parts of aircraft engine test state under limit load conditions as P test-限制 , the test state temperature is T test-限制 , the maximum equivalent stress of the test state assessment part is σ test-限制 ; in T test-限制 Under this condition, the yield strength of the material of the static pressure bearing part is σ 0.2test-限制 , the yield strength reserve of the pressure containment assessment part of the static pressure-bearing parts of the aero-engine test state n 0.2-test Calculate according to formula (10); n 0.2-test =s 0.2test-限制 / s test-限制 (10)。 10. The method for designing a pressure containment test for static pressure-bearing parts of an aircraft engine according to any one of claims 1 to 7, characterized in that: According to formula (11), the ultimate strength margin of the static pressure-bearing parts of the aircraft engine under test and working conditions is guaranteed to be equivalent; n b-work =n b-test (11) Among them, n b-work The ultimate strength reserve of the static pressure-bearing parts under the working state of the aircraft engine, n b-test It is the ultimate strength reserve for the pressure containment assessment of static pressure-bearing parts in the test state of aircraft engines; Determine n b-work include: Define the pressure load of static pressure parts of aircraft engine in working state under the limit load condition as P work-极限 The temperature of the static pressure-bearing parts of the aircraft engine in working condition is T work-极限 , the maximum equivalent stress of the working state assessment part is σ work-极限 ; in T work-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ bwork-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aircraft engine in working condition, pressure tolerance assessment part b-work Calculate according to formula (12); n b-work =s bwork-极限 / s work-极限 (12) Determine n b-test include: Define the pressure load of static pressure-bearing parts of aircraft engine test state under the ultimate load condition as P test-极限 , the test state temperature is T test-极限 , the maximum equivalent stress of the test state assessment part is σ test-极限 ; in T test-极限 Under this condition, the ultimate strength of the material of the static pressure bearing part is σ btest-极限 , the ultimate strength reserve of the static pressure-bearing parts of the aero-engine test state n b-test Calculate according to formula (13); n b-test =s btest-极限 / s test-极限 (13).

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