1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 4965-1:2012Metallic materials Dynamic force calibration for uniaxial fatigue testingPart 1: Testing systemsIncorporating Corrigendum January 2013BS ISO 4965-1:2012 BRITISH
2、 STANDARDNational forewordThis British Standard is the UK implementation of ISO 4965-1:2012. It supersedes BS 7935-1:2004, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee ISE/101/6, Fatigue testing of metals and metal matrix composites.A list of organi
3、zations 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 responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 201
4、2.ISBN 978 0 580 82070 0ICS 77.040.10 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2012.Amendments issued since publicationDate Text affected31 Janu
5、ary 2013 Correction to supersession information in national foreword.BS ISO 4965-1:2012 ISO 2012Metallic materials Dynamic force calibration for uniaxial fatigue testing Part 1: Testing systemsMatriaux mtalliques talonnage de la force dynamique uniaxiale pour les essais de fatigue Partie 1: Systmes
6、dessaiINTERNATIONAL STANDARDISO4965-1First edition2012-07-15Reference numberISO 4965-1:2012(E)BS ISO 4965-1:2012ISO 4965-1:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or util
7、ized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission 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
8、 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 4965-1:2012ISO 4965-1:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Normative references . 13 Terms, definitions, and symbols . 14 General requirements . 34.1 Temperature 34.2
9、 Dynamic testing system 35 Procedure 55.1 Initial checks . 55.2 Calibration procedure 66 Calculation of results . 76.1 Calculate DCD forces and measured force ranges 76.2 Replica test-piece Method A 86.3 Compliance envelope Method B 87 Report . 97.1 General information 97.2 Results of dynamic calibr
10、ation 107.3 Re-calibration .10Annex A (normative) Guidance on re-calibration to be supplied to the user . 11Annex B (informative) Guidance on estimation of the bandwidth of the testing system instrumentation .12Bibliography .13BS ISO 4965-1:2012ISO 4965-1:2012(E)ForewordISO (the International Organi
11、zation for Standardization) is a worldwide federation 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 establishe
12、d has the right to be represented on that committee. 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.I
13、nternational Standards are drafted in accordance 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. Publi
14、cation as an International Standard requires approval 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 ri
15、ghts.ISO 4965-1 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 5, Fatigue testing.This first edition of ISO 4965-1, together with ISO 4965-2, cancels and replaces ISO 4965:1979, which has been technically revised.ISO 4965 consists of the following parts
16、, under the general title Metallic materials Dynamic force calibration for uniaxial fatigue testing: Part 1: Testing systems Part 2: Dynamic calibration device (DCD) instrumentationiv ISO 2012 All rights reservedBS ISO 4965-1:2012ISO 4965-1:2012(E)IntroductionIn a dynamic test, the force experienced
17、 by the test-piece (Ft) might differ significantly from the force indicated by the testing system (Fi). The dynamic errors result from inertial forces acting on the force transducer and any dynamic errors in the electronics of the force indicating system. Inertial forces equate to the grip mass (int
18、erposed between the force transducer and the test-piece) multiplied by its local acceleration, and therefore depend ona) the amplitude of motion b) the frequency of motion, andc) the grip mass.The amplitude of motion will, in turn, depend on the applied force and the mechanical configuration of the
19、testing system, including the compliances of the load train, the test-piece, the reaction frame, and the base mounting. For a given frequency and over a given force range, different combinations of compliance values will result in different amplitudes of motion the motion of a grip holding a very co
20、mpliant test-piece may even be in the opposite direction (anti-phase) to that of the same grip holding a much stiffer test-piece.For the purpose of this part of ISO 4965, there must be a linear relationship between the applied force and the displacement of the actuator. Using Method A and the calcul
21、ated correction factor, the force measurement system will be dynamically calibrated to within 1 % of the applied force range. Using Method B and two dynamic calibration devices (DCDs) of different compliance, the force measurement system will be dynamically calibrated to within 1 % of the applied fo
22、rce range, if the actual test-piece has a compliance between those of the two DCDs.Method A (Replica test-piece method) This method is used for calibrating a dynamic testing system with a DCD, allowing errors of up to 10 % in the indicated force range to be corrected for, using a generated correctio
23、n factor. The DCD must have the same compliance and mass as the specimens to be tested and the entire load train must be the same as that to be used for the actual testing. Before commencing a new series of dynamic tests, the correction factor relating the indicated force range (Fi) to the test-piec
24、e force range (Ft) can be determined using a strain gauged replica test-piece. This factor can be applied either as a correction to the results or to modify the force applied by the testing system, reducing the dynamic force error to less than 1 %. This correction factor is dependent on test frequen
25、cy, and therefore will have to be determined over the entire range of anticipated test frequencies.Method B (Compliance envelope method) This method is used to calibrate a dynamic testing system for use with varying test-piece configuration, using two DCDs of different compliance. The low compliance
26、 DCD should have a compliance lower than that of any test-piece to be tested, and the high compliance DCD should have a compliance above that of any test-piece. An operating envelope of test-piece compliance versus frequency can be established for the testing system, within which dynamic errors are
27、maintained to within 1 % of the applied force range. It is assumed that the compliance of the load train is insignificant when compared with the compliance of either DCD. If this is not the case, and the machine is to be used with varying load train compliance values, additional calibration runs wil
28、l need to be performed. ISO 2012 All rights reserved vBS ISO 4965-1:2012BS ISO 4965-1:2012Metallic materials Dynamic force calibration for uniaxial fatigue testing Part 1: Testing systems1 ScopeThis part of ISO 4965 describes two methods (see Introduction) for determining the relationship between th
29、e dynamic force range (Ft) applied to a test-piece in a uniaxial, sinusoidal, constant amplitude test and the force range indicated (Fi) by the testing system.These methods are applicable to dynamic testing systems operating away from system resonant frequencies and are relevant to testing systems w
30、here the dynamic force measurement errors are either unknown or where they are expected to exceed 1 % of the applied force range.The dynamic force measurement errors are determined by comparison of the peak forces indicated by the dynamic testing system with those measured by the strain gauged dynam
31、ic calibration device (DCD). This DCD has previously undergone static calibration (see 5.2.1) against the testing system indicator.For Method A (Replica test-piece method), the dynamic calibration is applicable over the validated range of frequencies for that type of test-piece only. A frequency-dep
32、endent correction factor is applicable for the correction of dynamic force measurement errors of up to 10 % of dynamic force range. By using such a correction factor, the actual test-specimen dynamic force measurement error will be reduced to less than 1 % of the dynamic force range.For Method B (Co
33、mpliance envelope method), the dynamic calibration is applicable over the range of test frequencies validated for test-pieces whose compliance lies between those of the two DCDs. No correction factor is applicable, as Method B does not permit dynamic force measurement errors above 1 % of the dynamic
34、 force range.NOTE Annex A provides guidance on when the system should be re-calibrated by the methods described in this part of ISO 4965.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited appli
35、es. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring systemISO 4965
36、-2, Metallic materials Dynamic force calibration for uniaxial fatigue testing Part 2: Dynamic calibration device (DCD) instrumentation3 Terms, definitions, and symbolsFor the purposes of this part of ISO 4965, the terms, definitions, and symbols in ISO 4965-2 and the following apply. Figure 1 gives
37、a schematic diagram of the calibration set-up.INTERNATIONAL STANDARD ISO 4965-1:2012(E) ISO 2012 All rights reserved 1BS ISO 4965-1:2012ISO 4965-1:2012(E)Figure 1 Schematic diagram of ISO 4965 calibration methodology3.1correction factorCratio between the dynamic force range determined by a DCD (FDCD
38、) and the dynamic force range indicated by the testing system (Fi), at the same testing frequency3.2DCDdynamic calibration devicestrain-gauged replica test-piece (or, for Method B, proving device) that, for Method A, has the same mass and compliance as the specimens to be tested or, for Method B, is
39、 of known compliance3.3DCD forceFDCDforce measured by the DCD, calculated from iDCDafter static calibration against the testing systemNOTE See Formulae (2) and (3).3.4DCD indicationiDCDoutput of the DCD instrumentationNOTE As the DCD instrumentation needs to have previously been calibrated against e
40、lectrical standards, the DCD indication will be in electrical units, such as mV or mV/V.3.5DCD instrumentationinstrumentation used in conjunction with the DCD, including strain gauge bridge output conditioning electronics and displayNOTE The DCD instrumentation may also supply the DCD energising vol
41、tage it could then display the DCD output as an mV/V ratio.3.6dynamic force rangeFdifference between the maximum (peak) and minimum (valley) values of force under cyclic conditions2 ISO 2012 All rights reservedBS ISO 4965-1:2012ISO 4965-1:2012(E)3.7dynamic testing systemcombination of actuator, reac
42、tion frame, load train, and instrumentation used to perform cyclic force testing, indicating the applied peak and valley force values3.8indicated forceFiforce measured by the dynamic testing systems statically-calibrated force transducer and indicated by its instrumentation, under both static and dy
43、namic conditions3.9indication erroreidifference in the force ranges indicated by the testing system instrumentation and the DCD instrumentation, expressed as a percentage of the DCD force range3.10load trainall components, excluding the specimen/DCD, that transmit the force between the actuator and
44、the reaction frame of the dynamic testing system, including the force transducer, adaptors, grips, and other fixtures4 General requirements4.1 TemperatureThe ambient temperature at which the dynamic calibration of the uniaxial dynamic testing system is performed shall be recorded. It is recommended
45、that the calibration be performed at a constant ambient temperature, and care should be taken to shield the DCD from draughts and direct sunlight.4.2 Dynamic testing system4.2.1 Static calibrationThe dynamic testing system shall have a current certificate of static calibration to ISO 7500-1, Class 1
46、 or better, for the relevant loading conditions.4.2.2 Calibration frequenciesThe dynamic testing system shall be dynamically calibrated over the range of frequencies where dynamic testing is to be performed, with the exception of any test frequencies at which a system resonance affects the force mea
47、surement accuracy, as specified in 5.1.1. It is also recommended that, to keep amplitude errors to less than 0,2 %, the maximum test frequency should not exceed 25 % of the testing system instrumentations bandwidth (see Annex B) for two pole filter systems, or 6 % of this bandwidth for single pole f
48、ilter systems.Filtering of the measured forces directly affects the dynamic accuracy of these measured forces. Therefore, any filters shall be added before conducting the dynamic calibration. The calibration is only valid with the filters used at the time of calibration.If Method B is used, the same
49、 frequency range shall be used for each of the two DCDs. System resonant frequencies lead to localized areas of increased errors. Care must be taken to identify such areas, with both DCDs, so that actual testing is not performed at frequencies where excessive errors occur.4.2.3 Dynamic force rangeThe indicated force end levels used for the dynamic calibration procedure shall lie within the statically calibrated force range of the dynamic testing system, and at the peak values anticipated for the test-p
