BS ISO 4965-2-2012 Metallic materials Dynamic force calibration for uniaxial fatigue testing Dynamic calibration device (DCD) instrumentation《金属材料 轴向负荷疲劳试验机动态力校准 第2部分 动态校准设备(DCD)测试.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 4965-2:2012Metallic materials Dynamic force calibration for uniaxial fatigue testingPart 2: Dynamic calibration device (DCD) instrumentationIncorporating Corrigendum Janua

2、ry 2013BS ISO 4965-2:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 4965-2:2012. It supersedes BS 7935-2:2004, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee ISE/101/6, Fatigue testing of metals and metal m

3、atrix composites.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 responsible for its correct application. The British Standards Institution 2012. Publi

4、shed by BSI Standards Limited 2012.ISBN 978 0 580 82071 7ICS 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 pub

5、licationDate Text affected31 January 2013 Correction to supersession information in national foreword.BS ISO 4965-2:2012 ISO 2012Metallic materials Dynamic force calibration for uniaxial fatigue testing Part 2: Dynamic calibration device (DCD) instrumentationMatriaux mtalliques talonnage de la force

6、 dynamique uniaxiale pour les essais de fatigue Partie 2: Instrumentation pour quipement dtalonnage dynamiqueINTERNATIONAL STANDARDISO4965-2First edition2012-07-15Reference numberISO 4965-2:2012(E)BS ISO 4965-2:2012ISO 4965-2:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 201

7、2All 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 permission in writing from either ISO at the address below or ISOs member body in the count

8、ry 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 SwitzerlandBS ISO 4965-2:2012ISO 4965-2:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Term

9、s, definitions, and symbols . 13 Principle . 24 General requirements . 24.1 Temperature 24.2 DCD instrumentation 24.3 Dynamic voltage reference standard . 25 Calibration procedure 35.1 DC calibration . 35.2 Sinusoidal calibration 36 Calculation of results . 46.1 DC calibration results . 46.2 Sinusoi

10、dal calibration results 47 Calibration report 57.1 General information 57.2 Results of calibration . 57.3 Re-calibration . 5Annex A (informative) Calibration frequency content. 6Bibliography . 9BS ISO 4965-2:2012ISO 4965-2:2012(E)ForewordISO (the International Organization for Standardization) is a

11、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 established has the right to be represented

12、 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.International Standards are drafte

13、d 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. Publication as an International Standa

14、rd 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 rights.ISO 4965-2 was prepared by T

15、echnical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 5, Fatigue testing.This first edition of ISO 4965-2, together with ISO 4965-1, cancels and replaces ISO 4965:1979, which has been technically revised.ISO 4965 consists of the following parts, under the general title Metalli

16、c material Dynamic force calibration for uniaxial fatigue testing: Part 1: Testing systems Part 2: Dynamic calibration device (DCD) instrumentationiv ISO 2012 All rights reservedBS ISO 4965-2:2012ISO 4965-2:2012(E)IntroductionIn a dynamic test, the force experienced by the test-piece may differ sign

17、ificantly from the intended force indicated by the testing system. 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 (interposed between the force transducer

18、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 testing system, including the complia

19、nces of the load train, the test-piece, the reaction frame, and the base mounting.ISO 4965-1 describes two methods of determining the testing systems performance. Both of these methods require that the DCD instrumentation has previously been calibrated in accordance with this part of ISO 4965. ISO 2

20、012 All rights reserved vBS ISO 4965-2:2012BS ISO 4965-2:2012Metallic materials Dynamic force calibration for uniaxial fatigue testing Part 2: Dynamic calibration device (DCD) instrumentation1 ScopeIn order to perform a dynamic calibration of a uniaxial testing system, it is necessary to measure the

21、 forces experienced by the test-piece to known levels of accuracy this measurement is made by a dynamic calibration device (DCD) in place of the test-piece and the calibration method is described in ISO 4965-1. This part of ISO 4965 defines the calibration procedure for the DCDs instrumentation. The

22、 method for the analysis of the results is also described, leading to a range of testing frequencies over which the instrumentation is valid for use with DCDs in accordance with ISO 4965-1.2 Terms, definitions, and symbolsFor the purposes of this document, the following terms, definitions, and symbo

23、ls apply.2.1DCD dynamic calibration devicereplica test-piece or proving device2.2DCD energising voltageVEDC voltage used to energise the DCDs strain gauge bridgeNOTE The DCD energising voltage is expressed in volts.2.3DCD instrumentationinstrumentation used in conjunction with DCD, including strain

24、gauge bridge output conditioning electronics and displayNOTE The DCD instrumentation may also supply the DCD energising voltage it could then display the DCD output as an mV/V ratio.2.4dynamic voltage reference standardinstrument capable of generating specific sinusoidal voltage waveforms (with magn

25、itudes proportional to either actual or nominal DCD energising voltages) and DC voltagesNOTE 1 The dynamic voltage reference standard may be two separate pieces of equipment, one generating the DC voltages and the other generating the sinusoidal waveforms.NOTE 2 See References 1, 2, and 3.2.5peak vo

26、ltage valuemaximum value of voltage contained within a generated or measured sinusoidal waveformINTERNATIONAL STANDARD ISO 4965-2:2012(E) ISO 2012 All rights reserved 1BS ISO 4965-2:2012ISO 4965-2:2012(E)2.6valley voltage valueminimum value of voltage contained within a generated or measured sinusoi

27、dal waveform3 PrincipleGenerate a set of DC voltages using a dynamic voltage reference standard. Determine the difference between the values displayed by the DCD instrumentation and the values generated by the dynamic voltage reference standard.Similarly, generate a set of sinusoidal waveforms using

28、 the dynamic voltage reference standard in the range from DC to the maximum test frequency, with varying amplitudes and offsets. Compare the peak and valley voltage values displayed on the DCD instrumentation with the values generated by the dynamic voltage reference standard.To simulate laboratory

29、conditions, repeat the sinusoidal calibration with a known amount of harmonic distortion to ensure that the DCD instrumentation is capable of measuring such peak and valley voltage values correctly.4 General requirements4.1 TemperatureThe calibration of the DCD instrumentation shall be performed at

30、a temperature in the range from 18 C to 28 C, with the actual temperature being reported.4.2 DCD instrumentationThe DCD instrumentation reads and displays the output of the DCD. When the DCDs DC energising voltage (VE) is also supplied by the DCD instrumentation, this output will be an mV/V value wh

31、en it is supplied from an external source, the output will simply be an mV value (which can be converted to an mV/V value via division by the externally-supplied energising voltage). When the DCD output is varying in a sinusoidal manner (due to a dynamic force being applied to it), the instrumentati

32、on shall display the peak and valley values of this output. The resolution of the DCD instrumentation shall not be greater than 0,000 1 mV/V (equivalent to 0,000 1 VEmV).4.3 Dynamic voltage reference standardThe dynamic voltage reference standard generates DC voltage levels and sinusoidal voltage wa

33、veforms (specified in terms of amplitude, frequency, and DC offset), traceable to voltage standards within given uncertainties. In addition, it enables a specified amount of harmonic distortion to be added to the waveform to allow the performance of the DCD instrumentation to be determined under non

34、-ideal conditions.The expanded uncertainty (at a level of confidence of approximately 95 %) in the peak and valley voltages generated by the dynamic voltage reference standard shall not exceed 0,2 % of the voltage range (i.e. peak voltage valley voltage). In the DC case, the expanded uncertainty (at

35、 a level of confidence of approximately 95 %) of the generated voltage shall not exceed 2 VEV (e.g. for an excitation voltage of 10 V, the reference standard shall be capable of generating differential DC voltages in the range from 20 mV to +20 mV, with an expanded uncertainty of 20 V).The differenc

36、e between the output impedance of the dynamic voltage reference standard and the output impedance of any DCD to be used with the DCD instrumentation in ISO 4965-1 shall be less than 0,05 % of the DCD instrumentations minimum input impedance throughout its calibrated frequency range.NOTE The DCD inst

37、rumentations input impedance is likely to decrease with increasing frequency, and a mismatch between its input impedance and the output impedance of the system it is connected to will lead to errors this is why it is important that the minimum input impedance value be used. For example, for DCD inst

38、rumentation with a minimum input impedance of 100 k, to be used with DCDs with an output impedance of 350 , the output impedance of the dynamic voltage reference standard would need to lie between 300 and 400 .2 ISO 2012 All rights reservedBS ISO 4965-2:2012ISO 4965-2:2012(E)The dynamic voltage refe

39、rence standard shall have certified traceability to national electrical standards of measurement.5 Calibration procedure5.1 DC calibrationEnergise and connect both the DCD instrumentation and the dynamic voltage reference standard for a period of not less than 30 minutes prior to DC calibration.Use

40、the dynamic voltage reference standard to generate a set of nine DC voltages over the calibration range. As an example, for a calibration range from 2 mV/V to +2 mV/V and an energising voltage of 10 V, voltages from 20 mV to +20 mV in steps of 5 mV shall be used. Record the DCD instrumentation outpu

41、t at each voltage. Repeat the process twice to generate three sets of readings. When the DCD instrumentation supplies the DCD energising voltage, the DC voltage value shall be based on the actual generated voltage. When the DCD energising voltage is to be supplied from an external source, the DC vol

42、tage value shall be calculated from its nominal value.5.2 Sinusoidal calibrationEnergise and connect both the DCD instrumentation and the dynamic voltage reference standard for a period of not less than 30 minutes prior to sinusoidal calibration.Use the dynamic voltage reference standard to generate

43、 a set of seven sinusoidal waveforms, in accordance with Table 1, and as shown in Figure 1. When the DCD instrumentation supplies the DCD energising voltage, the amplitude and DC offset of the waveforms shall be based on the actual generated voltage. When the DCD energising voltage is to be supplied

44、 from an external source, the waveform amplitude and DC offset shall be calculated from its nominal value.For each waveform, vary the frequency over the range of interest and, at a minimum of three discrete frequencies, record the peak and valley DCD instrumentation output values.Table 1 Sinusoidal

45、calibration waveformsWaveform DC Offset Amplitude1 -1,5 mV/V 0,5 mV/V2 -1,0 mV/V 1,0 mV/V3 -0,5 mV/V 1,5 mV/V4 0,0 mV/V 2,0 mV/V5 +0,5 mV/V 1,5 mV/V6 +1,0 mV/V 1,0 mV/V7 +1,5 mV/V 0,5 mV/V ISO 2012 All rights reserved 3BS ISO 4965-2:2012ISO 4965-2:2012(E)Keyx timey dynamic reference standard output,

46、 in mV/VFigure 1 Sinusoidal calibration waveformsRepeat the sinusoidal calibration specified above but with a fixed amount of total harmonic distortion of 0,125 % 0,010 % added to the generated waveforms (see Annex A).Repeat the process to generate two sets of readings.6 Calculation of resultsCalcul

47、ate the results as specified in 6.1 to 6.2.6.1 DC calibration resultsThe DC calibration results for each of the nine applied DC voltages (see 5.1) shall be determined by calculating the difference between the values displayed on the DCD instrumentation and the value generated by the dynamic voltage

48、reference standard, for each of the three readings.If any single difference exceeds a value of 0,01 mV/V (equivalent to 0,01 VEmV), the instrumentation shall be deemed to have failed its DC calibration.6.2 Sinusoidal calibration resultsFor each of the waveforms applied (see 5.2), the sinusoidal cali

49、bration results shall be determined by calculating, at each discrete frequency: the difference between the peak value displayed on the DCD instrumentation and the peak value generated by the dynamic voltage reference standard; the difference between the valley value displayed on the DCD instrumentation and the valley value generated by the dynamic voltage reference standard.4 ISO 2012 All rights reservedBS ISO 4965-2:2012ISO 4965-2:2012(E)These differences shall both be expressed as a percentage