Data-driven aviation casing reliability design method

Abstract

The invention belongs to the field of reliability design, and particularly relates to a data-driven aviation casing reliability design method, which comprises the following steps of: determining a main failure minimum probability index by combining risk analysis according to a fault hazard analysis result in potential failure analysis results, and forming a quantitative design criterion of typical parts; and performing criterion design coding on the failure configuration of the typical part, the qualitative design criterion of the structural strength reliability and the quantitative design criterion of the typical part. According to the method, a multi-layer and failure configuration of a structure-failure mode-failure mechanism of a cartridge receiver component is established, all potential failure mode data are managed by taking the configuration as a basic architecture of a database, and a structure reliability design criterion is extracted from design, processing, assembly and use right life cycle failure avoidance measures, so that the comprehensiveness of the design criterion is ensured, and the reliability of the cartridge receiver component is improved. And through database updating and a linkage mechanism with the design criterion, the real-time performance of the reliability design criterion is ensured.

Description

Technical Field

[0001] This application belongs to the field of reliability design, and specifically relates to a data-driven reliability design method for aircraft casings. Background Technology

[0002] Currently, the reliability design principles for aero-engines are largely based on those for general electronic products, including the adoption of mature technologies and processes, simplified design, rational selection of raw materials and components, derating design, transient overstress protection design, thermal design, environmental protection design, and software reliability design. However, aero-engines operate continuously under high temperature, high pressure, and high load environments, resulting in extremely complex failure mechanisms. There is a lack of specific reliability design principles for the main structure of aero-engines. This is primarily because reliability design principles are broad in scope and lack effective methods for formulating them. Currently, the main structure of aero-engines is mainly guaranteed by strength reliability design principles, with the main form being a reserve coefficient for each failure mode not being lower than a certain value. However, advanced engines are constantly developing towards higher thrust-to-weight ratios and higher reliability, approaching design limits while simultaneously placing higher demands on reliability. This means that current structural strength reliability design principles cannot meet the reliability design requirements of advanced engines.

[0003] The specific drawbacks are as follows:

[0004] 1. General structural design principles are not applicable to mainframe structures, such as chassis reliability design;

[0005] 2. The design criteria for the strength and reliability of the casing rely on previous domestic and foreign research and development experience. However, it cannot effectively and timely transform new failure modes into design criteria. Furthermore, the design criteria mainly target static and dynamic thermal fatigue failures, primarily ensuring the structural integrity during use, and cannot effectively avoid various reliability-related failures throughout the entire life cycle. In other words, the comprehensiveness and real-time nature of the design criteria are insufficient.

[0006] 3. Current design criteria are mainly based on reserve coefficients, which cannot quantitatively characterize or control the divergence of various uncertain influencing factors. In other words, the design criteria cannot support uncertain design.

[0007] As a load-bearing and force-transmitting component of an aero-engine, the reliability design of the casing is crucial to the reliability of the aero-engine. Based on the analysis and research of the structure, stress and failure characteristics of the aero-engine casing, this application establishes a structural reliability design method for aero-engine casing components. Summary of the Invention

[0008] The purpose of this application is to provide a data-driven reliability design method for aircraft casings to address the problem that current structural strength reliability design criteria cannot meet the reliability design requirements of advanced engines.

[0009] The technical solution of this application is: a data-driven aircraft casing reliability design method, comprising:

[0010] Based on the structural composition and stress characteristics, determine the main failure modes and failure mechanisms, and establish the failure configurations of typical components;

[0011] Using the failure configurations of typical components as the analysis objects, we conduct failure data, failure mode effects and hazard analysis, and obtain the analysis results to establish a potential failure database.

[0012] The analysis objects of the potential failure database are used as the evaluation objects of the design criteria. Potential failure analysis is carried out, and the qualitative design criteria for structural strength and reliability are established based on the results of the potential failure analysis.

[0013] Based on the failure hazard analysis results in the potential failure analysis, and combined with the risk analysis, the minimum probability index of major failures is determined, and quantitative design criteria for typical components are formed.

[0014] The failure configurations of typical components, qualitative design criteria for structural strength and reliability, and quantitative design principles for typical components are coded according to the design criteria.

[0015] Preferably, the failure configuration of a typical component is established as follows:

[0016] The functional failure list of the casing was determined based on the casing's functional list and the FHA analysis results.

[0017] The functional failures in the functional failure list are classified at the casing component level.

[0018] Based on the relationship between the function, performance requirements, structural composition, failure modes, and failure propagation of the casing, the structural classification and hierarchical division of casing components are preliminarily determined;

[0019] The design drawings are classified and graded according to the agreed hierarchical division of the casing-type components, and a list of structural components is established;

[0020] Obtain the FMECA analysis results and failure list of the corresponding casing-type components, and combine them with the structural composition list to determine the failure mode list of the same type of structure, the same failure location, and the same component;

[0021] Analyze and determine the failure mechanisms corresponding to different failure modes in the failure mode list, and establish a failure mechanism list.

[0022] Preferably, the failures at the casing component level include structural failures, operational failures, and failures caused by unknown factors;

[0023] Failure to use includes damage from foreign objects, sand and gravel erosion, special external environments, improper operation, improper maintenance, aircraft-related factors, and replacement for convenience;

[0024] Structural failures include intermediate convention level and lowest convention level structural failures.

[0025] Preferably, in the failure mode list, the types of failure modes are combined by filtering each type of structure separately; the failure modes include fracture, wear, deformation, corrosion, connection, and leakage.

[0026] The failure mechanisms are divided into failures caused by structural integrity design not meeting requirements and failures caused by external and unpredictable causes; failures caused by insufficient structural integrity are divided into failures of single structures and failures of assemblies.

[0027] Preferably, a potential failure database is established as follows:

[0028] The failure configuration coding rule is determined to be structure coding - failure mode coding - failure mechanism coding;

[0029] Determine the structure of the potential failure mode library and the scope of failure objects, divide it into modules, and determine the input-output relationships and logical relationships between each module;

[0030] The requirements of standards and specifications are analyzed and broken down into specific structural components and technical activities, and a knowledge base for the corresponding version is established.

[0031] Establish a fault database based on the requirements for fault data used in system reliability analysis;

[0032] Different modules, knowledge bases, and fault databases are stored separately in an information-based manner to form a potential failure mode library.

[0033] Preferably, each module is a basic information preparation module, a new material process and technical information module, a working and environmental information module, a failure mode and mechanism analysis module, a failure cause analysis module, a failure impact analysis module, an occurrence probability and risk assessment module, a simulation and experimental verification module, a measures and implementation module, a compliance verification module, a risk compensation analysis module, and a maintainability analysis module.

[0034] Preferably, a structural coding rule is implemented, and the structure is divided into five agreed-upon levels according to the agreed-upon structural hierarchy. The structure is divided into a structural level code plus a specific structural sequence code for that level. The code of a lower level should include the code of the previous agreed-upon level.

[0035] Failure mode coding rules: The interval corresponding to the failure mode is numbered sequentially.

[0036] The failure mechanism coding rules are based on the casing configuration design. Failure mechanisms include two categories: external causes and insufficient structural integrity, which are represented by 0 and 1 respectively.

[0037] Preferably, potential failure analysis is performed as follows:

[0038] Based on the failure modes and failure mechanisms at different levels of the failure configuration design, the design, processing and assembly assurance measures, simulation verification requirements and test verification requirements are transformed into qualitative design criteria for typical structures of casing components.

[0039] Based on the failure configuration design, the failure modes of different levels of structure are determined. Different failure modes correspond to different failure mechanisms. Different failure mechanisms are used as the basis for deterministic reliability design criteria. According to the acceptable level of risk, the lowest probability level of different failure mechanisms is determined as the quantitative design criterion for structural strength reliability.

[0040] Preferably, the quantitative design criteria for typical components are:

[0041] The evaluation object is determined to be the structural component of the failure configuration design;

[0042] The minimum acceptable standard for users is determined based on a risk scoring table with probability and severity levels and minimum acceptable risk levels for different scores;

[0043] The relationship between severity levels and minimum probability levels is determined based on the acceptable risk level and risk scoring criteria; the minimum probability of occurrence and minimum acceptable probability corresponding to the failure mechanisms of different severity levels are determined based on the minimum acceptable risk level.

[0044] Reliability is used as a reliability index parameter. The principle for determining the structural reliability index is determined based on the lowest probability of occurrence and the lowest acceptable probability corresponding to the failure mechanism of different severity levels.

[0045] Preferably, the criteria are designed and coded as follows:

[0046] The numbering format adopts a 5-layer, 15-digit format; the 5 layers include version number code, execution stage code, unit code, responsible entity code, and principle sequence number.

[0047] The data-driven aircraft casing reliability design method of this application has the following advantages:

[0048] Developing design criteria based on the structure, stress, and failure characteristics of the aero-engine casing is more targeted and achieves the integration of design criteria with structural design.

[0049] A multi-layered failure mode-failure mechanism structure and failure configuration of the casing component are established. This configuration is used as the basic architecture of the database to manage all potential failure mode data. Furthermore, structural reliability design criteria are extracted from the design, manufacturing, assembly, and service life failure avoidance measures to ensure the comprehensiveness of the design criteria. Through database updates and linkage mechanisms with the design criteria, the real-time nature of the reliability design criteria is ensured.

[0050] Within the framework of reliability design criteria based on failure configurations, the severity of different failures can be objectively and effectively assessed. Based on the minimum acceptable risk requirements, the minimum probability of occurrence of various failures can be effectively determined, thus quantifying the design criteria for uncertainty. Attached Figure Description

[0051] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0052] Figure 1 A flowchart was developed for the structural strength and reliability design criteria of typical components in this application;

[0053] Figure 2 This is a schematic diagram of the design process for the failure configuration of the casing in this application;

[0054] Figure 3 This is a schematic diagram illustrating the determination of the functional failure list for the casing components in this application;

[0055] Figure 4 This is a schematic diagram illustrating the classification of the sources of casing failure in this application;

[0056] Figure 5 This is a schematic diagram illustrating the hierarchical structure of the casing in this application;

[0057] Figure 6 This is a schematic diagram of the intermediate hierarchical structure of this application;

[0058] Figure 7 This is a schematic diagram showing the structural components of the casing assembly in this application;

[0059] Figure 8 This is a schematic diagram of the first conventional level (function 2) of the outer casing structure in this application;

[0060] Figure 9 This is a schematic diagram of the first conventional level (function 3) of the outer casing structure in this application;

[0061] Figure 10 This is a schematic diagram of the first conventional level (function 4) of the outer casing structure in this application;

[0062] Figure 11This is a schematic diagram illustrating the hierarchical structure of the casing in this application;

[0063] Figure 12 This is a schematic diagram of the failure mechanism list for the casing in this application;

[0064] Figure 13 This is a schematic diagram illustrating the hierarchical structure of the casing in this application;

[0065] Figure 14 This is a schematic diagram of the potential failure mode library and system reliability analysis process in this application;

[0066] Figure 15 This is a schematic diagram of the database information storage based on the configuration design of this application;

[0067] Figure 16 A schematic diagram illustrating the basis and scope for formulating the structure-failure mapping and qualitative design criteria for the strength and reliability of the casing structure in this application;

[0068] Figure 17 A flowchart illustrating the process for developing reliability design criteria for the outer casing of this application;

[0069] Figure 18 This is a schematic diagram illustrating the coding rules for the reliability design criteria of typical components in this application;

[0070] Figure 19 This is a schematic diagram illustrating the update cycle of the structural strength and reliability design criteria for this application. Detailed Implementation

[0071] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] A data-driven approach to aircraft casing reliability design, such as Figure 1 It includes the following steps:

[0073] Step S100: Based on the structural composition and stress characteristics, determine the main failure modes and failure mechanisms, and establish the failure configurations of typical components; such as... Figure 2 .

[0074] Preferably, the failure configuration of a typical component is established as follows:

[0075] Step S110: Determine the functional failure list of the chassis based on the chassis's functional list and the FHA analysis results;

[0076] Based on the functional list of the casing and the FHA analysis results, determine the functional failure list of the casing, such as... Figure 3 The diagram shows a list of functions for the casing, including, but not limited to, maintaining specified airflow channels, bearing loads, connecting and transmitting forces, mounting and securing accessories, piping, and providing maintenance access. Functional hazard analysis considers limitations on casing design, including but not limited to temperature, humidity, operating load, specified weight, specified dimensional limitations, functional capacity, and unpredictable external factors that may cause functional failure. Functional failure includes complete loss of function, partial loss of function, or functional fluctuations.

[0077] Step S120: Classify the functional failures in the functional failure list at the casing component level;

[0078] For each functional failure, the failure is first classified at the casing component level, including structural failure, operational failure, and failure caused by unknown factors. This classification is used as a data element when building the failure database. Failures caused by multiple reasons should be marked simultaneously and the combined failure should be described.

[0079] Failure effects are further categorized into: damage from external objects, erosion from sand and gravel, special external environments, improper operation, improper maintenance, aircraft-related, and replacement for convenience. This category is used as a data element in the construction of the failure database, and failures caused by multiple reasons should be marked as multi-factor failures.

[0080] If the casing structure fails, it should be classified into intermediate-level and lowest-level structural failures according to the structural convention hierarchy.

[0081] like Figure 4 The diagram shows the classification of casing failure sources. Structural failures also include design-related failures and operational failures, such as... Figure 4 As shown by the dashed line.

[0082] Step S130: Based on the relationship between the function, performance requirements, structural composition, failure mode and failure propagation of the casing, the structural classification and hierarchical division of casing components are initially determined;

[0083] Based on the functional and performance requirements, structural composition, failure modes, and relationship between failure propagation of the chassis, the preliminary structural classification and hierarchical division of chassis components are shown in the figure. Underlying single chassis components are main functional components and other auxiliary functional components. Components include large parts and small parts, while auxiliary functional components include small parts and small components. For large parts, it is necessary to further distinguish their typical characteristics and locations to ensure comprehensive coverage of failure modes.

[0084] Step S140: Classify and grade the design drawings according to the agreed hierarchical division of the casing-type components, and establish a list of structural components;

[0085] First, based on the agreed-upon hierarchical structure of the S130 casing, classify and categorize the EBOM or component catalog from the design drawings. Functional components may differ from the drawings. Then, determine the following lists in sequence: the main functional components of the casing, the components related to the housing and related components, the typical features / parts list, and the small parts and components list. Each level of list should include all categories; structures of the same type do not need to be listed separately. For casing-type products, components are generally divided into housing components, mounting and fixing functional components, connecting functional components, and components providing maintenance access. The structural composition list of each main component of the casing is as follows: Figures 6-11 As shown.

[0086] Step S150: Obtain the FMECA analysis results and failure list of the corresponding casing-type components, and determine the failure mode list of the same type of structure, the same failure location, and the same component by combining the structural composition list.

[0087] To label the structures in the FMECA analysis results and fault data according to the structural composition list determined in step S140, each structural category is screened, and the failure mode types are merged. Failure modes include, but are not limited to: fracture (cracks, localized fracture, overall fracture, coating spalling, coating peeling, etc.); wear (localized wear, overall wear, etc.); deformation (dimensional changes, localized deformation, overall deformation, etc.); corrosion (ablation, rust, corrosion, abrasion, etc.); connection (adhesion, weld failure, loosening, detachment, peeling, etc.); and leakage (air leakage, gas leakage, lubricating oil leakage, fuel leakage, etc.).

[0088] Failure Mode Coding Rules: The intervals corresponding to the failure mode are numbered sequentially. The interval division principle is as follows: For example, the failure mode coding rule for cracks in the outer bypass casing is I51.II01.III01-501.

[0089] 1) Loss of function type: 101

[0090] 2) Dysfunctional type: 201

[0091] 3) Structural fracture type: 301

[0092] 4) Structural deformation type: 401

[0093] 5) Structural wear type: 501

[0094] 6) Structural corrosion type: 601

[0095] 7) Loose, detached, leaking, or blocked type: 701

[0096] 8) Degraded / Altered type: 801

[0097] 9) Failure mode coding for new materials, new processes, and new technologies: X-01~99.

[0098] Step S160: Analyze and determine the failure mechanisms corresponding to different failure modes in the failure mode list, and establish a failure mechanism list.

[0099] Failure mechanisms are categorized into failures caused by inadequate structural integrity design and failures due to external or unpredictable factors. Failures due to insufficient structural integrity are further divided into single-structure failures and component failures. Single-structure failures include, but are not limited to, insufficient static strength, buckling failure, low-cycle fatigue failure, high-cycle fatigue failure, and creep fatigue failure. In actual design, appropriate adjustments are made based on actual operating conditions, environmental loads, and development experience. Failures of casing-type components include, but are not limited to, thermal deformation incompatibility. In actual design, appropriate adjustments are made based on actual operating conditions, environmental loads, and development experience. Figure 12 .

[0100] Step S200: Using the failure configuration of a typical component as the analysis object, perform fault data, failure mode effects and hazard analysis, and obtain the analysis results to establish a potential failure database.

[0101] Preferably, a potential failure database is established as follows:

[0102] Step S210: Determine the failure configuration coding rule, which is structure coding - failure mode coding - failure mechanism coding;

[0103] The detailed coding requirements are as follows:

[0104] a) Structural Coding Rules: Based on the structural hierarchy, casing-type components are divided into 5 hierarchical levels. Therefore, the structural coding rule is: structural level code + specific structural sequence code for that level. The structural hierarchy coding rule is as follows: Figure 13 As shown, the lower-level code should include the code of the previous agreed level. For example, the outer bypass casing code rule is I51, the outer bypass casing housing assembly code rule is I51.II01, and the outer bypass casing housing code rule is I51.II01.III01.

[0105] b) Failure Mode Coding Rules: The intervals corresponding to the failure mode are numbered sequentially. The interval division principle is as follows: For example, the failure mode coding rule for cracks in the outer bypass casing is I51.II01.III01-501.

[0106] 1) Loss of function type: 101

[0107] 2) Dysfunctional type: 201

[0108] 3) Structural fracture type: 301

[0109] 4) Structural deformation type: 401

[0110] 5) Structural wear type: 501

[0111] 6) Structural corrosion type: 601

[0112] 7) Loose, detached, leaking, or blocked type: 701

[0113] 8) Degraded / Altered type: 801

[0114] 9) Failure Mode Coding for New Materials, New Processes, and New Technologies: X-01~99

[0115] c) Failure Mechanism Coding Rules: Based on the casing configuration design, failure mechanisms are divided into two categories: external causes and insufficient structural integrity, represented by 0 and 1 respectively. Each type of failure mechanism is represented by three Arabic numerals, with static strength failure designated as 01, buckling failure as 02, low-cycle failure as 03, high-cycle failure as 04, and creep as 05. For example, the coding rule for casing shell cracks caused by buckling failure is I51.II01.III01-501-02.

[0116] Step S220: Determine the structure of the potential failure mode library and the scope of failure objects, divide the modules, and determine the input-output relationships and logical relationships between each module;

[0117] Basic information preparation mainly involves designing the chassis failure configuration, updating and determining the structure of the potential failure mode library and the scope of failure targets. Specific element modules are consistent with the system reliability analysis, and are divided into 12 modules. The input-output relationship flow of each module is as follows: Figure 14 As shown. The system reliability analysis includes all modules, while the potential failure mode library only includes modules 1, 2, 3, 5, 6, 7, and 8. Module 4 can be adjusted as needed based on the minimum agreed-upon level of the configuration design.

[0118] The 12 modules are: basic information preparation module, new material process and technical information module, working and environmental information module, failure mode and mechanism analysis module, failure cause analysis module, failure effect analysis module, probability of occurrence and risk assessment module, simulation and experimental verification module, measures and implementation module, compliance verification module, risk compensation analysis module and maintainability analysis module.

[0119] Based on the system reliability analysis process of the engine structure, the logical relationships between different modules are identified, and the analysis elements, specific analysis requirements, and some implementation methods for each analysis module are determined. See Tables 1-8 for details. The first row contains the name of the analysis module, the second row contains the specific analysis elements for each module, the third row contains the responsible party, and the fourth row contains the specific analysis requirements and implementation methods.

[0120] Table 1. Requirements for the Basic Information Module of Potential Failure Mode Library Elements

[0121]

[0122] Table 2 Potential Failure Mode Library Elements - Information Requirements for New Materials and Processes

[0123]

[0124] Table 3. Requirements for Potential Failure Mode Library Elements - Operating Status and Environmental Information Module

[0125]

[0126] Table 4 Potential Failure Mode Library Elements - Failure Cause Analysis Requirements

[0127]

[0128] Table 5. Potential Failure Mode Library Elements - Failure Impact Analysis Requirements

[0129]

[0130] Table 6 Failure Impact Analysis Module

[0131]

[0132] Table 7. Elements of the Potential Failure Mode Library - Simulation and Experimental Verification Requirements

[0133]

[0134] Table 8 Potential Failure Mode Library Elements - Current Action Requirements

[0135]

[0136] Step S230: Analyze and decompose the requirements of the standard specifications into specific structural components and technical activities, and establish a knowledge base for the corresponding version;

[0137] Given the current lack of accumulated data on potential engine failures, reliability analysis should align with standards and specifications, breaking down the requirements of these standards and specifications into specific structural components and technical activities. Failure configuration elements should correspond to different levels of failure configuration design, ideally mirroring the failure mechanism. If this is not feasible, a direct correlation with the structural configuration design is acceptable. Relevant standards should at least include the propulsion system structural integrity outline, engine structural integrity outline, GJB 241A, CCAR 33, CCAR 25, MIL-HDBK-516C, aircraft requirements, and current structural strength and reliability design guidelines. A template for constructing the relevant knowledge base is shown in Table 9.

[0138] Table 9. Forward Design Knowledge Base Requirements Template

[0139]

[0140] The version of the standard should be specified during the construction of the knowledge base. Unless otherwise specified, the knowledge base information in the table is the latest standard version specified for the knowledge base.

[0141] Step S240: Establish a fault database according to the relevant requirements for fault data used in system reliability analysis.

[0142] To ensure the seamless application of engine development experience across all models and the inheritance of failure rate information, clear requirements must be established regarding the format and information needs of fault data used for potential failure analysis. Table 10 shows the relevant requirements for fault data used in system reliability analysis. Statistics are categorized by model, but the cumulative flight or operational time for each model must be noted. The source of the fault should clearly indicate the timing of its exposure, including but not limited to the engineering demonstrator development stage, prototype development stage, flight verification stage, type certification testing stage, and operational stage. Table 10 shows partial information from the fault database used for system reliability analysis.

[0143] Table 10 Fault Database for System Reliability Analysis

[0144]

[0145] Step S250: Store different modules, knowledge base and fault database separately in an information-based manner to form a potential failure mode library.

[0146] Database storage is organized into multiple views based on modules. The fault database can be a separate view, the potential failure mode library has 11 views, and the knowledge base contains 2 views. The left side of each view displays a unified failure configuration. Clicking on the corresponding element of the configuration allows you to extract all relevant fault information, standard-based knowledge information, and information related to potential failure analysis, design verification, and compensation. Figure 15The diagram shown illustrates information storage. Each level of the failure configuration tree should include a name and a code.

[0147] Step S300: The analysis objects of the potential failure database are used as the evaluation objects of the design criteria. Potential failure analysis is carried out, and the qualitative design criteria for structural strength and reliability are established based on the results of the potential failure analysis.

[0148] Potential failure analysis is performed as follows:

[0149] Step S310 involves designing different levels of failure modes and mechanisms based on the failure configuration, transforming the adopted design, manufacturing, and assembly assurance measures, simulation verification requirements, and experimental verification requirements into qualitative design criteria for typical structures of the casing components; for criteria that are not feasible in practice, relevant usage compensation principles for testing, monitoring, and maintenance should be provided. Figure 16 The diagram shows the interrelationships.

[0150] Step S320: Based on the failure configuration design, determine the failure modes of different structural levels. Different failure modes correspond to different failure mechanisms. These different failure mechanisms serve as the basis for deterministic reliability design criteria. Based on the acceptable risk level, determine the lowest probability level of each failure mechanism as a quantitative design criterion for structural strength reliability. Simultaneously, for different failure mechanisms, and considering the different design assurance and usage compensation measures in design, manufacturing, assembly, and use management, qualitative reliability design criteria are formed. The design criterion formulation process is as follows: Figure 17 As shown.

[0151] Step S400: Based on the failure hazard analysis results in the potential failure analysis results, and combined with the risk analysis, determine the minimum probability index of major failures, and form a quantitative design criterion for typical components.

[0152] Preferably, the quantitative design criteria for typical components are:

[0153] Step S410: Determine the structural components of the failure configuration design as the evaluation object;

[0154] Step S420: Determine the user's minimum acceptable standard based on the risk scoring table of probability level and severity level and the minimum acceptable risk level of different scores;

[0155] Table 11 shows a risk scoring table based on probability and severity levels, and Table 12 shows the minimum acceptable risk levels for different scores. Each type of failure must be at least acceptable with user consent, meaning the risk assessment score must be at least 10.

[0156] Table 11 Risk Scoring Criteria

[0157]

[0158] Table 12 Acceptable Risk Levels

[0159]

[0160] Step S430: Determine the relationship between severity level and minimum probability level based on the acceptable risk level and risk scoring criteria; determine the minimum probability occurrence level and minimum acceptable probability corresponding to the failure mechanism of different severity levels based on the minimum level of the acceptable risk level.

[0161] Table 13 defines the probability level classification, and Table 14 defines the severity level classification. The relationship between the severity level and the lowest probability level is determined based on the risk acceptable level and risk scoring criteria, as shown in Table 15.

[0162] Table 13 Definition of Probability Level Classification

[0163]

[0164] Table 14 Severity Level Classification Definitions

[0165]

[0166] Based on the minimum acceptable risk level of 10, the minimum probability of occurrence and the minimum acceptable probability corresponding to the failure mechanisms of different severity levels are determined as shown in Table 15.

[0167] Table 15 Structural Importance and Minimum Occurrence Probability Requirements

[0168]

[0169] Step S440: Using reliability as a reliability index parameter, the principle for determining structural reliability index is determined based on the lowest probability of occurrence and the lowest acceptable probability corresponding to the failure mechanism of different severity levels.

[0170] To ensure the designability of the indicators, this paper uses reliability as the reliability indicator parameter, denoted by R, and the probability of occurrence is denoted by P, where R+P=1 always holds true. Therefore, the principles for determining the reliability indicators of fighter jet structures are shown in Table 16.

[0171] Table 16 Principles for Determining Reliability Indicators

[0172]

[0173] The principles for selecting different failure reliability levels are explained below:

[0174] 1) The minimum reliability requirement for Severity Level I is 0.99999; this indicator does not exist for the outer bypass casing.

[0175] 2) The minimum reliability requirement for severity level II is 0.9999;

[0176] 3) The minimum reliability requirement for severity level III is 0.999;

[0177] 4) The minimum reliability requirement for severity level IV is 0.99.

[0178] 5. Typical component structural strength and reliability design criteria coding and management requirements.

[0179] Step S500: Code the failure configuration of typical components, the qualitative design criteria for structural strength and reliability, and the quantitative design criteria for typical components.

[0180] Preferably, the criteria are designed and coded as follows:

[0181] To ensure the effective implementation of design guidelines, these guidelines are categorized and numbered according to different stages such as failure assessment, structural design, material selection and processing, assembly, testing, and use and maintenance. This facilitates subsequent management and tracking. The relevant explanations are as follows:

[0182] The numbering format uses a 5-level, 15-digit system; the meaning of each level's code is as follows: Figure 18 The specific encoding rules are explained below:

[0183] a) Version number coding rules: V01~V09. The initial release version uses version 01. Subsequent versions are numbered sequentially as experience is accumulated. This version number is the version number of the entire design principle, not the version number of a single principle.

[0184] b) Execution phase code: Numbered between 01 and 05, where 01 represents before design drawing; 02 represents before unit assembly; 03 represents before engine installation; 04 represents before testing; and 05 represents execution during transportation and use.

[0185] c) Unit designation, which is consistent with the designation of the unit in the drawing. Taking the outer bypass casing as an example, this designation can be set as 51.

[0186] d) Responsible entity code: mainly based on the unit code finally implemented in the guidelines. 1001~9999 are structural design category, including structural design requirements for external units; 0001 is performance design category; 0002 is air system category; 0007 is strength design category; 0008 is process and material selection category; 0009 is use, maintenance, and standard parts category; 00013 is strength testing category; 0015 is assembly category; and 00016 is commissioning category.

[0187] e) Criterion Sequence Numbering: All design criteria are numbered sequentially, with a range and format of 0001 to 9999.

[0188] like Figure 19 As shown, the structural strength design criteria are gradually improved with the accumulation of internal and external field failure data, requiring regular updates and management according to two dimensions: natural time and development cycle. In the natural year dimension, the potential failure mode library is improved annually based on internal and external field failure data, and suggestions for improvement are provided for the current structural strength reliability design criteria. The adoption of these suggestions is studied and determined at major development milestones for each model, and the structural strength reliability design criteria are further refined at each major milestone.

[0189] Finally, a compliance analysis of the structural strength and reliability design criteria for typical components was conducted, as shown in Table 17.

[0190] Table 17 Compliance Analysis of Casing Structure Strength and Reliability Design Criteria

[0191] Model to be checked: XXX Inspector: XXX Inspection Date: XXXX-XX-XX

[0192]

[0193] In summary, the advantages of this application are as follows:

[0194] Developing design criteria based on the structure, stress, and failure characteristics of the aero-engine casing is more targeted and achieves the integration of design criteria with structural design.

[0195] A multi-layered failure mode-failure mechanism structure and failure configuration of the casing component are established. This configuration is used as the basic architecture of the database to manage all potential failure mode data. Furthermore, structural reliability design criteria are extracted from the design, manufacturing, assembly, and service life failure avoidance measures to ensure the comprehensiveness of the design criteria. Through database updates and linkage mechanisms with the design criteria, the real-time nature of the reliability design criteria is ensured.

[0196] Within the framework of reliability design criteria based on failure configurations, the severity of different failures can be objectively and effectively assessed. Based on the minimum acceptable risk requirements, the minimum probability of occurrence of various failures can be effectively determined, thus quantifying the design criteria for uncertainty.

[0197] Finally, it should be noted that the accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0198] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A data-driven reliability design method for aircraft casings, characterized in that, include: Based on the structural composition and stress characteristics, determine the main failure modes and failure mechanisms, and establish the failure configurations of typical components; Using the failure configurations of typical components as the analysis objects, we conduct failure data, failure mode effects and hazard analysis, and obtain the analysis results to establish a potential failure database. The analysis objects of the potential failure database are used as the evaluation objects of the design criteria. Potential failure analysis is carried out, and the qualitative design criteria for structural strength and reliability are established based on the results of the potential failure analysis. Based on the failure hazard analysis results in the potential failure analysis, and combined with the risk analysis, the minimum probability index of major failures is determined, and quantitative design criteria for typical components are formed. The failure configurations of typical components, qualitative design criteria for structural strength and reliability, and quantitative design principles for typical components are coded according to the design criteria.

2. The data-driven aircraft casing reliability design method as described in claim 1, characterized in that, The failure configuration of a typical component is established as follows: The functional failure list of the casing was determined based on the casing's functional list and the FHA analysis results. The functional failures in the functional failure list are classified at the casing component level. Based on the relationship between the function, performance requirements, structural composition, failure modes, and failure propagation of the casing, the structural classification and hierarchical division of casing components are preliminarily determined; The design drawings are classified and graded according to the agreed hierarchical division of the casing-type components, and a list of structural components is established; Obtain the FMECA analysis results and failure list of the corresponding casing-type components, and combine them with the structural composition list to determine the failure mode list of the same type of structure, the same failure location, and the same component; Analyze and determine the failure mechanisms corresponding to different failure modes in the failure mode list, and establish a failure mechanism list.

3. The data-driven aircraft casing reliability design method as described in claim 2, characterized in that, Failures at the casing component level include structural failures, operational failures, and failures caused by unknown factors; Failure to use includes damage from foreign objects, sand and gravel erosion, special external environments, improper operation, improper maintenance, aircraft-related factors, and replacement for convenience; Structural failures include intermediate convention level and lowest convention level structural failures.

4. The data-driven aircraft casing reliability design method as described in claim 2, characterized in that, The failure mode list is compiled by filtering each type of structure separately and then merging the types of failure modes; the failure modes include fracture, wear, deformation, corrosion, connection, and leakage. The failure mechanisms are divided into failures caused by structural integrity design not meeting requirements and failures caused by external and unpredictable causes; failures caused by insufficient structural integrity are divided into failures of single structures and failures of assemblies.

5. The data-driven aircraft casing reliability design method as described in claim 1, characterized in that, Establish a potential failure database as follows: The failure configuration coding rule is determined to be structure coding - failure mode coding - failure mechanism coding; Determine the structure of the potential failure mode library and the scope of failure objects, divide it into modules, and determine the input-output relationships and logical relationships between each module; The requirements of standards and specifications are analyzed and broken down into specific structural components and technical activities, and a knowledge base for the corresponding version is established. Establish a fault database based on the requirements for fault data used in system reliability analysis; Different modules, knowledge bases, and fault databases are stored separately in an information-based manner to form a potential failure mode library.

6. The data-driven aircraft casing reliability design method as described in claim 5, characterized in that, The modules are: basic information preparation module, new material process and technical information module, working and environmental information module, failure mode and mechanism analysis module, failure cause analysis module, failure effect analysis module, occurrence probability and risk assessment module, simulation and experimental verification module, measures and implementation module, compliance verification module, risk compensation analysis module, and maintainability analysis module.

7. The data-driven aircraft casing reliability design method as described in claim 5, characterized in that, Structural coding rules are established, and the components of the casing are divided into 5 agreed-upon levels according to the structural hierarchy. The coding is the structural level code plus the specific structural sequence code of that level. The code of a lower level should include the code of the previous agreed-upon level. Failure mode coding rules: The interval corresponding to the failure mode is numbered sequentially. The failure mechanism coding rules are based on the casing configuration design. Failure mechanisms include two categories: external causes and insufficient structural integrity, which are represented by 0 and 1 respectively.

8. The data-driven aircraft casing reliability design method as described in claim 1, characterized in that, Potential failure analysis is performed as follows: Based on the failure modes and failure mechanisms at different levels of the failure configuration design, the design, processing and assembly assurance measures, simulation verification requirements and test verification requirements are transformed into qualitative design criteria for typical structures of casing components. Based on the failure configuration design, the failure modes of different levels of structure are determined. Different failure modes correspond to different failure mechanisms. Different failure mechanisms are used as the basis for deterministic reliability design criteria. According to the acceptable level of risk, the lowest probability level of different failure mechanisms is determined as the quantitative design criterion for structural strength reliability.

9. The data-driven aircraft casing reliability design method as described in claim 1, characterized in that, The quantitative design criteria for typical components are as follows: The evaluation object is determined to be the structural component of the failure configuration design; The minimum acceptable standard for users is determined based on a risk scoring table with probability and severity levels and minimum acceptable risk levels for different scores; The relationship between severity levels and minimum probability levels is determined based on the acceptable risk level and risk scoring criteria; the minimum probability of occurrence and minimum acceptable probability corresponding to the failure mechanisms of different severity levels are determined based on the minimum acceptable risk level. Reliability is used as a reliability index parameter. The principle for determining the structural reliability index is determined based on the lowest probability of occurrence and the lowest acceptable probability corresponding to the failure mechanism of different severity levels.

10. The data-driven aircraft casing reliability design method as described in claim 1, characterized in that, The criteria design and coding are as follows: The numbering format adopts a 5-layer, 15-digit format; the 5 layers include version number code, execution stage code, unit code, responsible entity code, and principle sequence number.

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