英法双语文档，环境实验：冲击，含有测试项目及定义，测试描述等IECEc60068-2-27Edition 4.0 2008-02INTERNATIONALSTANDARDNORMEINTERNATIONALEBASIC SAFETY PUBLICATIONPUBLICATION FONDAMENTALE DE SECURITEEnvironmental testingPart 2-27: Tests- Test Ea and quidance: ShockEssais d'environnementPartie 2-27: Essais-Essai Ea et guide: ChocsINTERNATIONALELECTROTECHNICALCOMMISSIONCOMMISSIONELECTROTECHNIQUEINTERNATIONALEPRICE CODECODE PRIXWCs19.040SBN2-83189628-2260068-2-27|EC:2008CONTENTSFOREWORDINTRODUCTIONScope2 normative references3 Terms and definitions4 Description of test apparatus778994.1 Required characteristics4.2 Measuring syste………4.3 Mounting125 Severities136 Preconditioning..147 Initial measurements and functional performance test15Testing159 Recovery1510 Final measurements∴1511 Information to be given in the relevant specification1512 Information to be given in the test report16Annex A(normative) Selection and application of pulse shapes- Guidance. .........................17Annex B(informative) Shock response spectra and other characteristics of pulseshapes27Annex C(informative)Comparison between impact tests36Bibliography37Figure 1 -Pulse shape and limits of tolerance for half-sine pulse ...10Figure 2-Pulse shape and limits of tolerance for final-peak saw-tooth pulse0Figure 3- Pulse shape and limits of tolerance for trapezoidal pulse11Figure 4- Frequency characteristics of the overall measuring system12Figure A 1- Shock response spectrum of a symmetrical half-sine pulse19Figure A 2- Shock response spectrum of a final-peak saw-tooth pulseFigure A3- Shock response spectrum of a symmetrical trapezoidal pulseFigure B. 1-Framework or box containing oscillatory systems of which f,: f2 and f3 areexamples of resonance frequencies27Figure B. 2a-Exciting pulseFigure B. 2b-Responses for f,, f2 and f329Figure B2c - Spectra which result from an infinite number of frequencies, with f1, f2 andf3 shown as finite points on the continuous curvesFigure B 2- Shock response spectrum conceptFigure B 3- Framework containing damped multi-degree-of-freedom systemFigure B 4- Shock response spectrum of a half-sine pulse with ripple3360068-2-27@|EC:2008Figure B5- Spectrum of a final-peak saw-tooth 300 m/s,18 ms pulse compared withthe spectra of 200 m/s half-sine pulses with durations between 3 ms and 20 ms....... 35Table 1- Severities for shock testing14Table A 1-Examples of pulse shapes and test severities typically employed for variousapplications……,……Table A 2-EXamples of severities typically employed for various applications24460068-2-27|EC:2008NTERNATIONAL ELECTROTECHNICAL COMMISSIONENVIRONMENTAL TESTINGPart 2-27: Tests- Test Ea and guidance: ShockFOREWORDThe International Electrotechnical Commission(IEC) is a worldwide organization for standardization comprisingall national electrotechnical committees (EC National Committees). The object of iEc is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, lEc publishes International standards, Technical specificationsTechnical Reports, Publicly Available Specifications (PAS)and Guides (hereafter referred to as"IECPublication (s)). Their preparation is entrusted to technical committees: any IEC National Committee interestedin the subject dealt with may participate in this preparatory work. International, governmental and nongovernmental organizations liaising with the iEc also participate in this pre paration. IEc collaborates closelywith the International Organization for standardization (Iso)in accordance with conditions determined byagreement between the two organizations2) The formal decisions or agreements of lEc on technical matters express, as nearly as possible, an internationalconsensus of opinion on the relevant subjects since each technical committee has representation from allinterested IEC National Committees3IEC Publications have the form of recommendations for international use and are accepted by lEC NationalPublications is accurate, IEc cannot be held responsible for the way in which they are used or for anyinterpretation by any el4)In order to promote international uniformity, IEC National Committees undertake to apply IEc Publicationstransparently to the maximum extent possible in their national and regional publications. Any divergencebetween any EC Publication and the corresponding national or regional publication shall be clearly indicated inthe latter5)IEc provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment declared to be in conformity with an IEC Publication6)All users should ensure that they have the latest edition of this publication7)No liability shall attach to IEC or its directors, employees, servants or agents including individual experts andmembers of its technical committees and IEC National Committees for any personal injury, property damage orther damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) andexpenses arising out of the publication, use of, or reliance upon, this IEc Publication or any other IECPublications8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications isindispensable for the correct application of this publication9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject ofpatent rights. IEC shall not be held responsible for identifying any or all such patent rightsInternational Standard EC 60068-2-27 has been prepared by lec technical committee 104Environmental conditions classification and methods of testThis fourth edition cancels and replaces the third edition, published in 1987, and includes themerging of IEC 60068-2-29, second edition (1987). It constitutes a technical revisionThe major changes with regard to the previous edition concernthe merging of lec 60068-2-29 into this edition of lEc 60068-2-27, Part 2-29 will bewithdrawn as soon as this edition is publishedthe introduction of soft packaged specimens as defined in the IEC ad hoc working groupdocument agreed in Stockholm: 200060068-2-27@|EC:20085The text of this standard is based on the following documentsFDISReport on voting104/448/FD|s104/457/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in the above tableThis publication has been drafted in accordance with the iso/EC Directives, Part 2It has the status of a basic safety publication in accordance with IEC Guide 104This standard is to be used in conjunction with IEC 60068-1A list of all the parts in the Ec 60068 series, under the general title Environmental testing, canbe found on the iec websiteThe committee has decided that the contents of this publication will remain unchanged until themaintenanceresultdateindicatedontheiecwebsiteunderhttp://webstore.iecchinthedatarelated to the specific publication. At this date, the publication will bereconfirmedwithdrawnreplaced by a revised edition, oramended660068-2-27|EC:2008INTRODUCTIONThis part of lEc 60068 deals with components, equipments and other electrotechnicalproducts, hereinafter referred to as "specimens", which, during transportation, storage andhandling, or in use, may be subjected either to conditions involving relatively infrequent nonrepetitive or repetitive shocks. The shock test may also be used as a means of establishing thesatisfactory design of a specimen in so far as its structural integrity is concerned and as ameans of quality control. It consists of subjecting a specimen either to non-repetitive orrepetitive shocks of standard pulse shapes with specified peak acceleration and durationSpecification writers will find a list of details to be considered for inclusion in specifications inClause 11. The necessary guidance is given in Annex A60068-2-27@|EC:20087ENVIRONMENTAL TESTINGPart 2-27: Tests- Test Ea and guidance: Shock1 ScopeThis part of lEC 60068 provides a standard procedure for determining the ability of a specimento withstand specified severities of non-repetitive or repetitive shocksThe purpose of this test is to reveal mechanical weakness and/or degradation in specifiedperformances, or accumulated damage or degradation caused by shocks. In conjunction withthe relevant specification, this may be used in some cases to determine the structural integrityof specimens or as a means of quality control (see Clause A. 2)This test is primarily intended for unpackaged specimens and for items in their transport casewhen the latter may be considered to be part of the specimen. If an item is to be testedunpackaged, it is referred to as a test specimen. However, if the item is packaged, then theitem itself is referred to as a product and the item and its packaging together are referred to asa test specimen. When used in conjunction with IEC 60068-2-47, this standard may be used fortesting packaged products. This possibility was included in the 2005 version of IEC 60068-2-47for the first timeThis standard is written in terms of prescribed pulse shapes. Guidance for the selection andapplication of these pulses is given in Annex a and the characteristics of the different pulseshapes are discussed in Annex BWherever possible, the test severity and the shape of the shock pulse applied to the specimenshould be such as to reproduce the effects of the actual transport or operational environmentto which the specimen will be subjected, or to satisfy the design requirements if the object ofthe test is to assess structural integrity (see Clauses A2 and A. 4)For the purposes of this test, the specimen is always mounted to the fixture or the table of theshock testing machine during testingNOTE The term shock testing machine is used throughout this standard, but other means of applying pulseshapes are not excludedOne of the responsibilities of a technical committee is, wherever applicable, to make use ofbasic safety publications in the preparation of its publications2 Normative referencesThe following referenced documents are indispensable for the application of this document. Fordated references, only the edition cited applies. For undated references, the latest edition ofthe referenced document (including any amendments)applieslEC 60068-1, Environmental testing- Part 1 General and guidancelEC 60068-2-47: 2005, Environmental testing-Part 2-47: Tests -Mounting of specimens forvibration, impact and similar dynamic testsIEC 60068-2-55, Environmental testing- Part 2-55: Tests- Test Ee and guidance: Bounce860068-2-27@|EC:2008lEC60721-3-1, Classification of environmental conditions-Part 3: Classification of groups ofenvironmental parameters and their severities- Section 1: StorageIEC 60721-3-5, Classification of environmental conditions Part 3: Classification of groups ofenvironmental parameters and their severities- Section 5: Ground vehicle installationsGuide 104, The preparation of safety publications and the use of basic safety publications andgroup safety publications3 Terms and definitionsFor the purposes of this document, the following terms and definitions applyNOTE The terms used are, for the most part, defined in ISo 2041[111 or IEC 60068-1. The following additionalterms and definitions are also applicable for the purposes of this standard3.1check pointpoint located on the fixture, on the table surface of the shock-testing machine or on thespecimen as close as possible to the fixing point, and in any case rigidly connected to itNOTE 1 A number of check points are used as a means of ensuring that the test requirements are satisfiedNOTE 2 If more than four fixing points exist, the relevant specification should state the number of fixing points tobe used as check pointsNOTE 3 In special cases, for example, for large or complex specimens, the check paints will be prescribed by therelevant specification if not close to the fixing pointsnotE 4 Where a large number of small specimens are mounted on one fixture, or in the case of a small specimenwhere there are a number of fixing points, a single check point (that is the reference point)may be selected for thederivation of the control signal. This signal is then related to the fixture rather than to the fixing points of thespecimen(s). This procedure is only valid when the lowest resonance frequency of the loaded fixture is well abovethe upper frequency of the test3.2fixing pointpart of the specimen in contact with the fixture or the table of the shock-testing machine at apoint where the specimen is normally fastened in serviceNOTE If a part of the real mounting structure is used as the fixture, the fixing points are taken as those of themounting structure and not of the specimen3.3standard acceleration due to the earth's gravity, which itself varies with altitude andgeographical latitudeNOTE For the purposes of this standard, the value of g, is rounded up to the nearest unity, that is 10 m/s2.repetition ratenum ber of shocks per second3.5shock severitycombination of the peak acceleration the duration of the nominal pulse and the number ofshocks1 Figures in square brackets refer to the bibliography