1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 10785:2011Space systems Bellows Design and operationBS ISO 10785:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 10785:2011. Th
2、e UK participation in its preparation was entrusted to T e c h n i c a l Committee ACE/68/-/1, Space systems and operations - Design, Engineering and Production.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to incl
3、ude all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 66620 9 ICS 49.140 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Poli
4、cy and Strategy Committee on 31 October 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 10785:2011Space systems Bellows Design and operationSystmes spatiaux Souffleries Conception et fonctionnement ISO 2011Reference numberISO 10785:2011(E)First edition2011-10-01ISO10785INT
5、ERNATIONAL STANDARDBS ISO 10785:2011ISO 10785:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without pe
6、rmission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2011 All rights reservedBS
7、 ISO 10785:2011ISO 10785:2011(E)Contents PageForeword ivIntroduction v1 Scope 12 Normative references .13 Terms and definitions .14 Abbreviated terms .55 Requirements .55.1 General .55.2 Design requirements 65.3 Material requirements 85.4 Fabrication and process control requirements .95.5 Quality as
8、surance requirements .95.6 Operation and maintenance requirements .105.7 Specific qualification test requirements .12Annex A (informative) Design safety factors .14 ISO 2011 All rights reserved iiiBS ISO 10785:2011ForewordISO (the International Organization for Standardization) is a worldwide federa
9、tion of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committ
10、ee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance
11、with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires appr
12、oval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 10785 was prepared by Technical Committe
13、e ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations.ISO 10785:2011(E)iv ISO 2011 All rights reservedBS ISO 10785:2011IntroductionThe bellows for space systems is usually used under severe conditions, such as high pressure, extremely low temperatures, large defl
14、ection, or high inner flow speed. The design safety factor of the bellows tends to be small in order to satisfy two different function requirements simultaneously. One is the function of the pressure bearing component, which all pressure components have, and the other is the special function to acco
15、mmodate installation misalignment, thermal expansion or contraction and displacement induced by large deformation of the pressurized propellant tank.There are many items to be considered for design and manufacture such as hoop stress, bulging stress, buckling strength, flow-induced vibration, and cy
16、clic deflection.This International Standard establishes general and specific requirements for bellows in order to provide safe and reliable bellows hardware and operations.Some examples of the design safety factors are shown in Annex A at the end of this International Standard.ISO 10785:2011(E) ISO
17、2011 All rights reserved vBS ISO 10785:2011BS ISO 10785:2011INTERNATIONAL STANDARD ISO 10785:2011(E)Space systems Bellows Design and operation1 ScopeThis International Standard specifies general and detailed requirements for bellows used in space systems. It establishes requirements with regard to m
18、aterial, design, analysis, fabrication, material, testing, inspection and operation for space use.This International Standard is applicable to metallic bellows which are used as pressure bearing components and are integrated into a pressure system. This International Standard is not applicable to en
19、gine bellows or valve bellows.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applie
20、s.ISO 14623:2003, Space systems Pressure vessels and pressurized structures Design and operation3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1acceptance testrequired formal test conducted on flight hardware to ascertain that the materials, man
21、ufacturing processes and workmanship meet specifications and that the hardware is acceptable for intended usage3.2bellowscorrugated single-layer or multi-layer elastic casing, when integrated into a duct assembly, capable of performing linear, shear and angular movementsNOTE 1 A bellows consists of
22、both a convolution section and a mechanical linkage section, which serves as a bellows restraint. The most common mechanical linkage types are gimbal-type and braided-type. In some cases a bellows contains an internal liner or flow tube for the purpose of improving flow capability.NOTE 2 See Figure
23、1.3.3bellows stiffnessratio between an applied force and the resulting bellows displacement3.4burst pressurepressure level at which rupture or unstable fracture of the pressurized hardware item occurs3.5bulging stressmeridional or axial stress at the convolution section induced by pressure ISO 2011
24、All rights reserved 1BS ISO 10785:20111Key1 internal pressureFigure 1 Bellows3.6componentfunctional unit that is viewed as an entity for the purpose of analysis, manufacturing, maintenance, or record keepingNOTE Adapted from ISO 14623:2003.3.7critical conditionmost severe environmental condition in
25、terms of loads, deflection, pressures and temperatures, or combination thereof, imposed on systems, subsystems, structures and components during service lifeISO 14623:2003, definition 2.123.8deflectioncontraction or expansion along its longitudinal axis, angular rotation, or lateral offsetNOTE See F
26、igure 2.12Key1 axial deflection2 angular rotationFigure 2 DeflectionISO 10785:2011(E)2 ISO 2011 All rights reservedBS ISO 10785:20113.9design burst factormultiplying factor applied to maximum expected operating pressure (MEOP) or maximum design pressure (MDP) 3.20 to obtain the design burst pressure
27、3.10design burst pressuredifferential pressure that pressurized hardware must withstand without bursting in the applicable operational environmentNOTE Design burst pressure is equal to the product of the MEOP or MDP and a design burst factor.ISO 14623:2003, definition 2.163.11design safety factordes
28、ign factor of safetyfactor of safetymultiplying factor to be applied to the limit load and/or maximum expected operating pressure (MEOP) or maximum design pressure (MDP) 3.20ISO 14623:2003, definition 2.173.12detrimental deformationstructural deformation, deflection or displacement that prevents any
29、 portion of the structure or other system from performing its intended function or that jeopardizes mission successNOTE Adapted from ISO 14623:2003, definition 2.19.3.13fatigueprocess of progressive localized permanent structural change occurring in a material/structure subjected to conditions which
30、 produce fluctuating stresses and strains at some point or points and which may culminate in cracks or complete fracture after a sufficient number of fluctuationsISO 14623:2003, definition 2.233.14fatigue lifenumber of cycles of stress or strain of a specified character that a given structure or com
31、ponent of a structural assembly can sustain (without the presence of flaws) before failure of a specified nature occursNOTE Adapted from ISO 14623:2003, definition 2.24.3.15fracturetype of failure mode in a material/structure which is generally preceded by a large amount of plastic deformation3.16fl
32、awlocal discontinuity in a structural materialEXAMPLES Crack, cut, scratch, void, delamination disbond, impact damage and other kinds of mechanical damage.NOTE Adapted from ISO 14623:2003, definition 2.25.3.17hoop stresscircumferential stress at the convolution section induced by pressureISO 10785:2
33、011(E) ISO 2011 All rights reserved 3BS ISO 10785:20113.18leak-before-burstLBBdesign concept which shows that at maximum expected operating pressure (MEOP) 3.20 potentially critical flaws will grow through the wall of a metallic pressurized hardware item and cause pressure relieving leakage rather t
34、han burst or rupture (catastrophic failure)NOTE Adapted from ISO 14623:2003, definition 2.35.3.19limit loadmaximum expected load, or combination of loads, which a structure or a component in a structural assembly is expected to experience during its service life, in association with the applicable o
35、perating environmentsNOTE 1 Load is a generic term for thermal load, pressure, external mechanical load (force, moment, or enforced displacement) or internal mechanical load (residual stress, pretension, or inertial load).NOTE 2 The corresponding stress or strain is called limit stress or limit stra
36、in.NOTE 3 Limit load is sometimes referred to as design limit load.NOTE 4 Adapted from ISO 14623:2003, definition 2.36.3.20maximum expected operating pressureMEOPhighest differential pressure which a pressurized hardware item is expected to experience during its service life and retain its functiona
37、lity, in association with its applicable operating environmentsNOTE 1 MEOP includes the effects of temperature, transient peaks, relief pressures, regulator pressure, vehicle acceleration, phase changes, transient pressure excursions, and relief valve tolerance.NOTE 2 Some projects may replace MEOP
38、with maximum design pressure (MDP), which takes into account more conservative conditions.NOTE 3 Adapted from ISO 14623:2003, definition 2.41.3.21mechanical linkage sectionsection within bellows assembly that will serve as the bellows restraint for thrust force by pressure, deflection, or other fact
39、ors3.22personnels approachaction or state of a ground crew approach when near to the bellows or another component while the component is pressurized3.23proof factormultiplying factor applied to the limit load or maximum expected operating pressure (MEOP) or maximum design pressure (MDP) 3.20 to obta
40、in proof load or proof pressure for use in acceptance testingISO 14623:2003, definition 2.503.24proof test pressurepressure level used to give evidence of satisfactory workmanship and material quality and/or establish maximum initial flaw sizes for safe-life demonstrationISO 10785:2011(E)4 ISO 2011
41、All rights reservedBS ISO 10785:20113.25qualification testrequired formal contractual tests conducted at load levels and durations in order to demonstrate that the design, manufacturing, and assembly of flight-quality structures have resulted in hardware that conforms to specification requirementsNO
42、TE In addition, the qualification test may validate the planned acceptance programme, including test techniques, procedures, equipment, instrumentation, and software.3.26repairaction on a nonconforming product to make it acceptable for the intended useNOTE 1 Repair includes remedial action taken on
43、previously conforming product to restore it for use, for example as part of maintenance.NOTE 2 Unlike rework, repair can affect or change parts of the nonconforming product.3.27refurbishmentrenovation and restoration to intended use condition3.28service lifeperiod of time (or number of cycles) that
44、starts with the manufacturing of the pressurized hardware and continues through all acceptance testing, handling, storage, transportation, launch operations, orbital operations, refurbishment, re-testing, re-entry or recovery from orbit, and reuse that may be required or specified for the itemISO 14
45、623:2003, definition 2.573.29work hardening effecteffect of strengthening material by plastic deformationNOTE The representative material is 300 series corrosion-resistant steel.4 Abbreviated termsLBB leak-before-burstMDP maximum design pressureMEOP maximum expected operating pressureNDI non-destruc
46、tive inspectionQA quality assuranceS-N stress versus number of cycles to failureNOTE Plots of S-N data are used in the fatigue test.5 Requirements5.1 GeneralClause 5 presents the requirements for design, stress analysis, material selection and characterization, fabrication and process control, and q
47、uality assurance, as well as operational requirements including maintenance, repair, refurbishment and storage for bellows in a pressure system.ISO 10785:2011(E) ISO 2011 All rights reserved 5BS ISO 10785:2011Safety requirements such as the design safety factor and safety measures in operation shoul
48、d comply with appropriate facility/agency requirements. Examples of design safety factor are shown in Annex A.5.2 Design requirements5.2.1 Loads, pressures, and environmentsThe anticipated pressure-temperature-deflection history and other associated environments throughout the service life of bellow
49、s in a pressure system shall be determined in accordance with specified mission requirements, also including flight ultimate conditions.The fundamental parameters or conditions in loads, pressures, and environments for bellows are considered as follows:a) internal/external pressure;b) temperature;c) fluid (working medium);d) flow velocity;e) deflection;f) pre-loads;g) life-cycle;h) vibration, shock, acceleration;i) externally applied installation loads; j) handling loads.NOTE Give additional specific requireme
