1 Scope
This document provides general procedures and methods for the structural analysis of components for aerospace applications, giving information on samples, analysis test procedures, methods for decomposition of structural units and identification of structural elements, and the basis for structural discrimination to be considered.
This document is applicable to semiconductor integrated circuits, semiconductor discrete devices, optoelectronic devices, resistors, capacitors, electrical connectors, relays, switches, fuses, quartz crystals, acoustic devices. Filters. The structural analysis of RF components and other categories of components shall be carried out with reference to other categories of components.
2 Normative references
The contents of the following documents constitute the essential provisions of this document through the normative references in the text. Among them, note the date of the reference document, only the date of the corresponding version applicable to this document; do not note the date of the reference document, its latest version (including all the revision of the list) applicable to this document.
GB/T 19000 Quality management system Basics and terminology
3 Terms. Definitions and abbreviations;
3.1 Terminology and definitions.
The terms defined by GB/T 19000 and the following terms and definitions apply to this document.
3.1.1
Construction
The parts of a component and their combination, including physical form, materials, processes and interfaces.
3.1.2 construction analysis
Construction analysis
The use of inspection, test analysis and other methods, as well as review and recalculation, simulation and other means to obtain the design, process and materials of components and other elements, analysis and evaluation of its functional performance to meet the inherent reliability of the situation, process quality capabilities, application of environmental adaptability, potential hazards and other factors of activity.
3.1.3
Construction unit
A unit in which the physical structure or function of a component can be distinguished.
3.1.4
construction element
The characteristics of a construction unit that affect the inherent reliability and operational reliability of a component.
3.2 Abbreviations
The following abbreviations apply to this document.
CA: Construction Analysis
DPA: Destructive Physical Analysis
FA: Failure Analysis
4 Structural analysis process.
4.1 General process
The general process for structural analysis of aerospace components is shown in Figure 1.
4.2 CA sample and information confirmation
Prior to the preparation of the structural analysis programme, it is advisable to obtain information and confirm the structural analysis samples by reference to the following items:
a) Adequate information on the development background of the sample, e.g. whether the component is a new product or an upgrade of an existing product, a customised or generic product, the maturity of the product and the development capability of the production unit;
b) A full understanding of the status of the structural analysis samples, such as whether the components have been mass-produced or are in the development of prototypes or engineering samples, the design status, whether the process status is solidified, etc;
c) The number of samples for structural analysis is based on the principle that comprehensive structural information can be obtained, and in order to accurately obtain certain structural elements, additional semi-finished parts can be selected for supplementary analysis.
4.3 Investigation of the application environment
4.3.1 Overview
The reliability of components is divided into inherent reliability and application reliability, inherent reliability and components inherent functional design, structural design, material selection and processing technology is directly related to the objective; application reliability is the reliability of the application environment, and environment-related, that is, in a certain application conditions of reliable work of components may not be adapted to another specific working environment, is Therefore, it is important to investigate the application environment of the components.
4.3.2 Scope of investigation
The scope of the survey should include the following:
a) by the component development unit to provide the intended application of its products environmental conditions;
b) The application environment requirements of the components provided by the component use unit;
c) structural analysis unit according to the functional performance of the components to investigate the application of the components should have the scope of the environment.
4.3.3 Investigation items
The survey project should include the following:
a) the application of the assembly conditions, sealing conditions, possible exposure to solvents;
b) temperature range, temperature change rate, number of cycles, ultimate temperature retention time, etc;
c) the pressure environment of the application . The rate of change, retention time limits, etc;
d) Humidity and salt environment, etc;
e) Type of mechanical stress, magnitude, period, etc;
f) power, current, voltage, etc. frequency, etc:
g) Heat dissipation, magnetic field, electromagnetic environment, etc;
h) irradiation environment, atomic oxygen environment, etc.
4.4 Development of the structural analysis programme
4.4.1 Overview
The structural analysis programme should be guided by the purpose of the analysis. Taking into account the background information of the component development and the target application environment, the structural unit decomposition and structural element identification of the component structure, the selection of the structural analysis test items, and the design of a reasonable test procedure according to the sample situation, form an executable operation plan.
4.4.2 Preparation of structural unit and element information
In order to ensure that the structural analysis and evaluation process covers all design, process and material elements of the component in a comprehensive manner, and to improve the relevance of the analysis and evaluation. It is advisable to first decompose the structural units of the sample and to determine the structural elements. This is done by:
a) where available, by analysing the design and process documentation of the product provided by the manufacturer;
b) the collection of information from previous structural analyses or destructive physical analyses (DPA) of similar samples;
c) Select a small number of samples for non-destructive (e.g. X-ray examination) or destructive analysis (e.g. sample profiling). To obtain
4.4.3 Programme factors
4.4.3 Protocol factors
The following factors need to be considered in developing a programme:
a) The generic inherent reliability of the product;
4.4.4 Scheme elements
The following elements should be considered in the structural analysis programme:
Basic information about the sample, such as component type, name, type specification, quality level, production unit, quantity, batch, etc;
The target application context of the component. The background of the development;
The basic composition of the component and the typical failure modes of similar structures;
The results of the structural unit decomposition of the component. Identification of structural elements and the corresponding analysis tests;
Integration and optimisation of the analysis test procedure.
4.5 Implementation of structural analysis tests
The following considerations should be taken into account during the implementation of the structural analysis tests:
a) The test procedure, test items, test personnel, instruments and equipment, environment, etc. determined according to the analysis plan are in accordance with the relevant technical requirements. The test procedure, test items, test personnel, instruments and equipment, environment, methods, etc. shall be in accordance with the relevant technical requirements. Test data records should be complete and detailed;
b) In the implementation of each 8, the data shall be collected in conjunction with the structural unit division of the component and the structural elements contained in each structural unit and the interface between the elements;
c:) The information and data collected shall be analysed in a timely manner during the analysis, and when the analysis reveals new reliability influencing factors, the necessary adjustments shall be made to the preliminary plan in a timely manner;
d) In the process of structural analysis, especially in the process of destructive testing, attention should be paid to the protection of the samples, and the previous tests should not affect the subsequent tests.
4.6 Structural discrimination and evaluation
After the components have been analysed in accordance with the structural analysis programme, the design, process and materials of the components should be evaluated based on the results of the analysis and the conditions of the aerospace application. The evaluation and assessment mainly includes the following:
a) Evaluation of the rationality of the structural design: to check whether prohibited structures are used; to evaluate the rationality of the structural design based on the relevant design standards, specifications and requirements, combined with the requirements of the aerospace application and the results of the analyses:
b) Process design and quality check: to check whether prohibited processes are used; to evaluate the level of production process of components, the reasonableness of the process implementation and the existence of potential hazards;
c) Material suitability analysis: to check for the presence of materials that are prohibited for use in aerospace; material analysis of samples to evaluate the reasonableness of the material selection;
d) Assemblability analysis: according to the sample packaging design, combined with the relevant requirements of the word aviation assembly process and reliability requirements, analysis of the component packaging structure, technology, materials to meet the requirements of the aviation assembly process;
e) Failure potential analysis: Based on the results of the structural elements of the structural unit of the sample, combined with the failure mechanism of similar components, past failure cases, etc., the potential failure potential is analysed. Based on the matching between the component structure, process and material, we analyse whether the production unit has mature process capability for mass production and stable access to qualified materials in the process of realising the product.
5 Structural analysis methods .
5.1 Decomposition of structural units
5.1.1 Principles of structural unit decomposition
The structural unit decomposition is one of the key steps in structural analysis and is divided into the following principles:
a) It is appropriate to decompose the overall structure of the component in accordance with the physical unit layer by layer to obtain the structural elements, as a basis for determining the analysis project, determining the direction of structural element identification, and planning the test procedure;
b) It is generally advisable to decompose to the smallest physical unit of the component and to the smallest limits of the process. However, attention should also be paid to the typicality and maturity of the device structure, etc. For the recognized typical structural unit - generally do not need to be decomposed to the smallest structural unit of the part.
5.1.2 Structural unit decomposition methods
The general approach to structural unit decomposition is as follows
a) A preliminary analysis of the structural category of the component.
b) To understand the previous structural analysis of components of the same structure, and to get an idea of their structural unit composition. This is the basis for considering the structural unit composition of the component to be analysed.
e) Combining the functional characteristics of the components and the maturity of the structural units, a tree diagram is used to decompose the structural units of the components to be analysed, layer by layer, until the structural elements of the lowest level structural units can be identified. An example of a typical structural unit decomposition of a component for aerospace applications is given in Appendix A.
5.2 Identification of structural elements
5.2.1 Identification of structural elements
The structural elements of each structural unit need to be identified in relation to the specific function and performance of the structural unit. The set of structural elements should reflect the reliability of the structural unit in a comprehensive manner and facilitate the acquisition of information by means of corresponding tests or simulations. Examples of structural elements for typical aerospace components are given in Appendix B.
5.2.2 Structural element information acquisition
After determining the structural elements, the reliability properties reflected in the structural elements and the objective physical and chemical characteristics of the structural units are combined to set up the corresponding test items and simulation methods to obtain the structural element information for evaluating the reliability of the structure. After the test items have been selected, an optimised structural analysis test procedure is established, in which the analysis samples are allocated in a general order of non-destructive and then destructive analysis tests:
a) Firstly, the standard test methods for components and the non-standard test methods for DPA and FA processes carried out in the past are collected;
b) The structural elements of the component's structural unit and the corresponding analytical tests are listed;
c) To collate and summarise the physical, chemical and thermal analyses carried out during the analysis process, taking into account the structural characteristics of the components:
d) Integration and optimisation of all analysis and test items to obtain a complete analysis and test flow;
e) Complete the analytical tests and record the results, including but not limited to numerical values, photographs, diagrams. The results include, but are not limited to, numerical values, photographs, graphs, etc.
Appendix C gives an example of the structural analysis test procedure for typical components used in word navigation.
5.3 Structural discrimination
5.3.1 Judgement based on standard specifications
The criteria based on standard specifications include:
a) National and foreign military and aerospace standards for this type/type of component, and industry standards for aerospace companies regarding the design, process and material requirements of components;
b) the relevant lists of prohibitions and restrictions and requirements in each field, as well as the design, process and material requirements that are explicitly prohibited;
c) a summary of the specific requirement clauses and items and an analysis of their scope of application, with the requirements criteria for structural analysis-specific structural discrimination by category. Examples of standard specification criteria are given in Appendix D.
5.3.2 Judgement based on typical structure of components
The basis for discrimination based on the typical structure of a component can be obtained according to the following procedure:
a) In accordance with the structural category of the component, a typical sample of aerospace-grade or highly reliable components is selected, with reference to the preferred catalogues of domestic and foreign aerospace companies;
b) The samples are decomposed from outside to inside according to the basic method of structural analysis, and the structural elements are identified;
c) Through the structural analysis of typical highly reliable aerospace components, we will obtain detailed information on the structural design, process and materials of these components.
c) the structural analysis of typical highly reliable aerospace components to obtain detailed information on the structural design, processes and materials of these components;
d) The information obtained is collated according to the level of structural unit decomposition and analysed in terms of the principles of use and scope of application as a physical criterion for structural discrimination.
5.3.3 Failure case based judgement
The basis of the identification based on failure cases can be obtained in the following way:
a) Research into publicly reported failure cases and failure mechanisms of similar devices, as well as internal failure cases of individual users.
For cases where the cause of failure is related to the structure of the component, analysis is carried out to identify the background. Failure processes, failure modes. Failure mechanism
The information on the failure process, failure mode, failure mechanism, failure cause, etc.
e) The design, process and material aspects of the components reflected in the failure cases are summarised and analysed in terms of their applicability, forming the basis for the structural judgement of previous cases. Examples of structural criteria for failure cases are given in Appendix E.
5.3.4 Judgements based on simulation results
For structural analysis of components where it is difficult to obtain the structural information in a physico-chemical manner and to make a judgement, software simulation can be used.
Foreword
1 Scope
2 Normative references
3Terms, definitions and abbreviations
4Structural analysis process
5 Structural analysis methods
Annex A (informative) Example of structural unit decomposition of components for aerospace use
Annex B (Informative) Example of structural element composition for aerospace components
Annex C (Informative) Example of a structural analysis test procedure for aerospace components
Annex D (informative) Example of standard specification structure criteria
Annex E (informative) Examples of structural criteria for failure cases
