BS ISO 9538-2017 Aerospace series Hydraulic tubing joints and fittings Planar flexure test《航空航天系列 液压管接头和配件 平面弯曲试验》.pdf

1、Aerospace series Hydraulic tubing joints and fittings Planar flexure test BS ISO 9538:2017 BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National foreword This British Standard is the UK implementation of ISO 9538:2017. The UK participation in its preparation was

2、entrusted to Technical Committee ACE/69, Aerospace hydraulic systems, fluids and components. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsib

3、le for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017 ISBN 978 0 580 85847 5 ICS 49.080 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards

4、Policy and Strategy Committee on 30 June 2017. Amendments/corrigenda issued since publication Date Text affected BRITISH STANDARD BS ISO 9538:2017 ISO 2017 Aerospace series Hydraulic tubing joints and fittings Planar flexure test Srie arospatiale Joints et raccords des tuyauteries hydrauliques Essai

5、 de flexion plane INTERNATIONAL STANDARD ISO 9538 Second edition 2017-04-15 Reference number ISO 9538:2017(E) BS ISO 9538:2017 ISO 9538:2017(E)ii ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of t

6、his publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in

7、the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org BS ISO 9538:2017 ISO 9538:2017(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms and defi

8、nitions . 1 4 Device for flexure test . 1 5 Flexure test specimens . 3 6 Stress determination 3 7 Procedure. 4 7.1 Instrumentation and strain gauges . 4 7.2 Frequency 5 7.2.1 Test frequency 5 7.2.2 Natural frequency of the specimens . 5 7.2.3 Determination of tube length 5 7.3 Bending stress calibra

9、tion of test specimen 5 8 Requirements 5 Bibliography 6 ISO 2017 All rights reserved iii Contents Page BS ISO 9538:2017 ISO 9538:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing

10、 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 committee. International organizations, governmental and non-governmental, in liais

11、on with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Dire

12、ctives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that s

13、ome 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. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent decla

14、rations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity

15、assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommitt

16、ee SC 10, Aerospace fluid systems and components. This second edition cancels and replaces the first edition (ISO 9538:1996), of which it constitutes a minor revision. The changes are as follows: the publication dates of ISO 7257 and ISO 7169 in the introduction were removed in order to reflect the

17、most updated versions of those documents.iv ISO 2017 All rights reserved BS ISO 9538:2017 ISO 9538:2017(E) Introduction This document describes a planar flexure test procedure for hydraulic tubing joints and fittings. The test procedure can be applied as an alternative to the rotary test procedure s

18、pecified in ISO 7257 . The qualification test procedures for tube fittings are specified in ISO 7169 . Other test methods can be used as long as they develop the same results as the procedure specified in this document. ISO 2017 All rights reserved v BS ISO 9538:2017This page deliberately left blank

19、 Aerospace series Hydraulic tubing joints and fittings Planar flexure test 1 Scope This document specifies a f lexure test procedure for reconnectable and permanent hydraulic tube joints. This procedure is intended for conducting flexure tests on fittings with high-strength hydraulic tubes made of c

20、orrosion-resisting steel, titanium and aluminium for use on commercial and military aircraft. 2 Normative references There are no normative references in this document. 3 Terms and definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use

21、 in standardization at the following addresses: IEC Electropedia: available at http:/ /www.electropedia.org/ ISO Online browsing platform: available at http:/ /www.iso.org/obp 4 Device for flexure test The test device should be similar to that shown in Figure 1. It shall consist of a vibrator, a man

22、ifold to receive at least six test specimens, and a hydraulic supply unit capable of constantly maintaining the static operating pressure during testing, including monitors inducing the shutdown of the system in the event of pressure drop. INTERNATIONAL ST ANDARD ISO 9538:2017(E) ISO 2017 All rights

23、 reserved 1 BS ISO 9538:2017 ISO 9538:2017(E) Key 1 pressure supply 2 pressure gauge 3 test specimen Figure 1 Set-up of test drive Three test specimens are attached to two opposite ends of the manifold, which is rigidly mounted on the vibrator. A hose assembly establishes the connection with the hyd

24、raulic supply unit. The vibrator shall allow for vibration frequencies up to 300 Hz. Details of the set-up are shown in Figure 2.2 ISO 2017 All rights reserved BS ISO 9538:2017 ISO 9538:2017(E) Key 1 stress cycle in the tube during vibration 2 angle gauges for optical amplitude control 3 pressure ge

25、neration and monitoring in the test specimen 4 acceleration cycle of vibrator Figure 2 Details of set-up 5 Flexure test specimens The test specimens shall consist of the tube fitting to be tested (for example straight union), the test tube and the fitting to seal the tube. 6 Stress determination The

26、 maximum permissible flexure fatigue stress of the test tubing is determined for the combined stress level. The combined stress, f , is composed of the tensile stress, p , resulting from the internal pressure and the wall thickness of the tube, and the bending stress, b . Strain gauges shall be used

27、 to demonstrate the bending stress, and the deflection can be checked during testing by means of angle gauges. A typical stress cycle is illustrated in Figure 3. The bending stress, b , is determined by the maximum permissible flexure fatigue stress of the test tube and shall be specified for each a

28、pplication. ISO 2017 All rights reserved 3 BS ISO 9538:2017 ISO 9538:2017(E) Key 1 maximum stress 2 minimum stress p mean axial stress produced by internal pressure b stress caused by bending f combined stress, p+ b Figure 3 Typical test cycle 7 Procedure 7.1 Instrumentation and strain gauges A stra

29、in gauge shall be mounted on each test specimen. They shall be mounted as shown in Figure 4. Their location should be as follows. a) For tube sizes to DN 16: approximately 4 mm from the attachment-point tube to fitting. b) For tube sizes to DN 20 and above: approximately 8 mm from the attachment-poi

30、nt tube to fitting. Key 1 strain gauge 2 vibrator 3 see 7.1 4 length giving natural frequency of between 110 Hz and 120 Hz Figure 4 Location of gauges4 ISO 2017 All rights reserved BS ISO 9538:2017 ISO 9538:2017(E) 7.2 Frequency 7.2.1 Test frequency It is recommended to perform the test at approxima

31、tely 100 Hz. 7.2.2 Natural frequency of the specimens To minimize the power input of the vibrator used, the natural frequency of the specimens should be within the frequency range 110 Hz to 120 Hz. The test frequency shall be approximately 10 % to 20 % below the natural frequency of the specimens to

32、 prevent their resonance range from being reached. 7.2.3 Determination of tube length Screw the fully assembled tube, fitted with strain gauges, into the header in order to determine the tube length required. Connect the strain gauges, apply the nominal pressure and vibrate the tube. The tube length

33、 shall be adjusted until the natural frequency of the specimen is between 110 Hz and 120 Hz. 7.3 Bending stress calibration of test specimen Submit the prepared tube to a static load (F) corresponding to the specified bending stress (see Clause 4) in order to produce the required moment. After the t

34、ube bending setting is complete, introduce the specified pressure and read the stress transmitted by the strain gauge on an oscilloscope. Start the vibrator and increase the vibration amplitude of the vibrator until the oscillograph shows the previously determined stress value. The angle gauge allow

35、s the deflection(s) to be read for further control. The angle gauge shall be mounted at the end cap of the test specimen. To control the deflection of the test specimen, a suitable stroboscope with variable flash frequency shall be used. 8 Requirements The flexure test specimens shall withstand 107

36、cycles. Leakages and failures are not acceptable. ISO 2017 All rights reserved 5 BS ISO 9538:2017 ISO 9538:2017(E) Bibliography 1 ISO 7169 , Aerospace Separable tube fittings for fluid systems, for 24 degree cones, for pressures up to 3 000 psi or 21 000 kPa Procurement specification, inch/metric 2

37、ISO 7257 , Aircraft Hydraulic tubing joints and fittings Rotary flexure test6 ISO 2017 All rights reserved BS ISO 9538:2017This page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services. BSI is

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