1、BRITISH STANDARD BS EN 658-3:2002 Advanced technical ceramics Mechanical properties of ceramic composites at room temperature Part 3: Determination of flexural strength The European Standard EN 658-3:2002 has the status of a British Standard ICS 81.060.30 BS EN 658-3:2002 This British Standard, havi
2、ng been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 19 September 2002 BSI 19 September 2002 ISBN 0 580 40416 1 National foreword This British Standard is the offi
3、cial English language version of EN 658-3:2002. It supersedes DD ENV 658-3:1993 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics, which has the responsibility to: A list of organizations represented on this committee
4、 can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Searc
5、h” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obl
6、igations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary
7、 of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEU
8、ROPENNE EUROPISCHENORM EN6583 August2002 ICS81.060.30 SupersedesENV6583:1992 Englishversion AdvancedtechnicalceramicsMechanicalpropertiesofceramic compositesatroomtemperaturePart3:Determinationof flexuralstrength CramiquestechniquesavancesPropritsmcaniques descramiquescompositestempratureambiante Dt
9、erminationdelarsistanceenflexion HochleistungskeramikMechanischeEigenschaftenvon keramischenVerbundwerkstoffenbeiRaumtemperatur Teil3:BestimmungderBiegefestigkeit ThisEuropeanStandardwasapprovedbyCENon6July2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditio
10、nsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversi
11、oninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxe
12、mbourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENn
13、ationalMembers. Ref.No.EN6583:2002EEN6583:2002(E) 2 Contents page Foreword3 1 Scope 4 2 Normativereferences 4 3 Principle4 4 Terms,definitionsandsymbols .4 5 Apparatus .5 5.1 Testmachine 5 5.2 Testjig .5 5.3 Datarecordingsystem . .5 5.4 Dimensionmeasuringdevices . 5 6 Testspecimens 5 7 Testspecimenp
14、reparation . 6 7.1 Machiningandpreparation. 6 7.2 Numberoftestspecimens 6 8 Testprocedures . 7 8.1 Displacementrate . .7 8.2 Measurementofdimensions . .7 8.3 Testingtechnique . .7 8.4 Testvalidity . .8 9 Calculationofresults 8 9.1 Testspecimenorigin .8 9.2 Flexuralstrength. .8 10 Testreport 9 Biblio
15、graphy 11EN6583:2002(E) 3 Foreword Thisdocument(EN6583:2002)hasbeenpreparedbyTechnicalCommitteeCEN/TC184“Advancedtechnical ceramics“,thesecretariatofwhichisheldbyBSI. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyFebrua
16、ry2003,andconflictingnationalstandardsshallbewithdrawnatthelatest byFebruary2003. ThisdocumentsupersedesENV6583:1992. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Fi
17、nland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain, Sweden,SwitzerlandandtheUnitedKingdom. EN658hassixparts: Part1:Determinationoftensileproperties. Part2:Determinationofcompressiveproperties. Part3:Determinationofflexuralstrength. Part4:Determinati
18、onofinterlaminarshearstrengthbycompressionloadingofnotchedtestspecimens. Part5:Determinationofinterlaminarshearstrengthbyshortspanbendtest(threepoints). Part6:Determinationofinterlaminarshearstrengthbydoublepunchshearing.EN6583:2002(E) 4 1Scope ThispartofEN658describesamethodforthedeterminationofthe
19、flexuralstrengthofceramicmatrixcomposite materialswithcontinuousfibrereinforcement,underthreepointorfourpointbendatroomtemperature. Thismethodappliestoallceramicmatrixcompositeswithacontinuousfibrereinforcement,unidirectional(1D), bidirectional(2D),andtridirectionalxDwith(2x or=3)asdefinedinENV13233
20、,loadedalongoneprincipal axisofreinforcement. NOTE Themethodshouldnotbeusedtoobtainabsolutevaluesofstrengthfordesignpurposes. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthete
21、xt,andthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). ENISO75001, Meta
22、llicmaterialsVerificationofstaticuniaxialtestingmachinesPart1:Tension/compression testingmachines(ISO75001:1999). ENV13233, ISO3611, Micrometercallipersforexternalmeasurements . 3Principle Atestspecimenofspecifieddimensionsisflexionloadedtofractureinsuchawaythatfailureoccursintensionor compressional
23、ongoneprincipalaxisofreinforcement.Thetestisperformedatconstantcrossheaddisplacement rate. 4 Terms,definitionsandsymbols ForthepurposesofthisEuropeanStandard,thefollowingterms,definitionsandsymbolsandthosegivenin ENV13233apply. 4.1 maximumflexuralforce, F m highestrecordedforceinaflexuraltestonthete
24、stspecimenwhentestedtofailure 4.2 flexuralstress, s thenominalstressontheoutersurfaceofthetestspecimen,calculatedatmidspan NOTE Thisstressisconventionallycalculatedaccordingtothebeamtheory,whosebasicassumptionscannotbemetby ceramicmatrixcompositematerials. 4.3 flexuralstrength, s f,m maximumflexural
25、stressappliedtoatestspecimenthatfracturesduringaflexuraltestEN6583:2002(E) 5 5Apparatus 5.1 Testmachine Themachineshallbeequippedwithasystemformeasuringtheforceappliedtothetestspecimen.Thesystem shallconformtograde1accordingtoENISO75001. 5.2 Testjig Thetestjigiscomposedoftwoparts,linkedtothefixedand
26、mobilepartsofthemachine.Ithastwooutersupport rollersandone(threepointbend)ortwo(fourpointbend)innersupportrollers. Thecylindricalrollersshallhaveadiameterof4mmto10mm.Theirlengthshallbeatleastequaltothewidth ofthetestspecimen.Theyshallbemadeofamaterialwithahardnessatleastequaltothatofthetestspecimen.
27、 Theaxesoftherollersshallbeparalleltowithin0,01mm/mm. Theouterrollers(threeandfourpointbend)andinnerrollers(fourpointbend)shallbefreetorotate (seeFigure1). Eithertwoorthreerollers,forthreepointorfourpointbendrespectively,shallbefreetopivotaroundanaxis paralleltothelongitudinaldirectionofthetestspeci
28、men,inordertoadapttothenonparallelismoftheupperand lowerfacesofunmachinedtestspecimens(seeFigure1). Thedistancebetweenrollersshallbeinaccordancewithclause6. Theinnerrollersshallbecentredwithrespecttotheouterrollerstowithin0,2mm.Inthecaseoffourpointbend, thetestjigshallensuresymmetricalloadingofthete
29、stspecimen. 5.3 Datarecordingsystem Acalibratedrecordershallbeusedtorecordtheforcetimecurve.Theuseofadigitaldatarecordingsystem combinedwithananaloguerecorderisrecommended. 5.4 Dimensionmeasuringdevices Devicesusedformeasuringlineardimensionsofthetestspecimenshallbeaccurateto 0,1mm.Micrometers shall
30、beinaccordancewithISO3611. 6 Testspecimens RecommendedtestspecimendimensionsaregiveninTable1.Thesedimensionshavebeensuccessfullyused andtakeintoaccountthefollowingfactors: theamountofmaterialunderloadshallberepresentativeofthenatureofthematerialandofthereinforcement structure.Thissetsminimumlimitsto
31、thespanandtothewidthandthicknessofthetestspecimen.Inthecase offlexural,asopposedtotensiletesting,thedistributionofthelongitudinalreinforcementthroughthethickness hastobeconsidered.Whenthisdistributionisnotsymmetricalwithrespecttotheneutralplane,careshallbe takentoensurethatitissimilarbetweentestspec
32、imens. Twotypesoftestspecimenscanbedistinguished: asfabricatedtestspecimens,whereonlythelengthandthewidtharemachinedtogivetothetestspecimens thespecifiedsize.Inthiscasethetensileandcompressivesurfacesmaybeunmachinedandthusirregular; machinedtestspecimens,wherethelength,thewidthandthethicknessofthete
33、stspecimenhavebeen machined.EN6583:2002(E) 6 Toleranceonthicknessisonlyformachinedtestspecimens.Forasfabricatedtestspecimens,themaximum differenceinthicknessofthreemeasurements(atthecentreandateachendoftheouterspanlength)shallnot exceed5%oftheaverageofthethreemeasurements. Thethicknessofthetestspeci
34、menandthedistancebetweentheinnerandouterroller(s)shallbechosensoasto avoidshearfailure.Thisisachievedbysettingaminimumlimittotheratiobetweenthemomentarmandthetest specimenthickness(seeTable1).Avalueof10iscommonlyusedandtranslatesintoaminimum L/hratioof20in threepointbend,andaminimum( L L i )/hratioo
35、f20infourpointbendwith L i = L/3. Table1Recommendedtestspecimenandspandimensions Dimensionsinmillimetres 1D,2D,xD Tolerance l t ,totallength L+10 +1 b,width 10 +0,2 h,thickness 2,5 +0,2 Innerspan L i ,fourpointbend 25 +0,1 Outerspan L,fourpointbend 75 +0,1 L,threepointbend 50 +0,1 NOTE Ifitisnecessa
36、rytodefinetestspecimensofdifferentdimensions,theconditionsofclause6shouldbetakeninto account. 7 Testspecimenpreparation 7.1 Machiningandpreparation Duringcuttingout,careshallbetakentoalignthelongitudinaltestspecimenaxiswithoneoftheprincipalaxesof reinforcement. Testspecimensmaybetestedwitheithermach
37、inedornonmachinedtensileandcompressivesurfaces.Insome casesmachiningisnotrecommendedbecauseitmaycausedamagetothematerialnearthetensileand compressivesurfaces.Whenmachiningthesesurfaces,careshallbetakentomaintainareinforcementgeometry acrossthethicknessofthetestspecimen,whichisrepresentativeofthemate
38、rialintheasprocessedcondition.In particular,itshallbeassuredthatthesymmetryofanoriginallysymmetricreinforcementgeometryispreservedin thetestspecimencrosssectionaftermachining. Machiningparameterswhichavoiddamagetothematerialshallbeestablishedanddocumented.These parametersshallbeadheredtoduringtestsp
39、ecimenpreparation. 7.2 Numberoftestspecimens Atleastfivevalidtestresults(8.4)arerequired. Fortestspecimenswithanonsymmetricreinforcementgeometrywithrespecttotheneutralplane,testsin twoorientationsforwhichthetensileandcompressivefaceareinterchangedmaybenecessary. NOTE Ifstatisticalevaluationisrequire
40、d,thenumberoftestspecimensshouldbeinaccordancewithENV8435 .EN6583:2002(E) 7 8 Testprocedures 8.1Displacement rate Useacrossheaddisplacementratewhichallowstestspecimenfailurewithin1min.Thedisplacementrateshallbe reported. 8.2 Measurementofdimensions 8.2.1 Testspecimendimensions Thewidthandthicknesssh
41、allbemeasuredtothenearest0,01mminthreepointsnearthecentreforthreepoint bendandbetweentheinnerrollersforfourpointbend,andateachendofthetestspecimen. Thearithmeticmeansofthemeasurementsshallbeusedforcalculations. 8.2.2 Distancesbetweensupportingrollers Thedistancebetweenaxesoftheouterrollersandforfour
42、pointbendalsotheinnerrollers,shallbemeasuredto thenearest0,1mm. NOTE Thiscanbeachievedbytheuseofatravellingmicroscopeorothersuitabledeviceaccurateto0,05mm. 8.3 Testingtechnique 8.3.1 Testspecimenmounting Thetestspecimenshallbeinstalledinthetestjigcentredwithrespecttotherollersandwithitslongitudinala
43、xis perpendiculartotheaxesoftherollers. NOTE Itisrecommendedtouseasettingtoolforthispurpose. Zerotheloadcelloutput.Whenrequired,asmallpreloadcanbeappliedinordertomaintaincorrectpositioning ofthetestspecimen.Thispreloadshallnotincreasebeyond5%oftheexpectedfailureforceatanytime. 8.3.2Measurements setthedisplacementrateonthetestmachine; zerotheloadcell; recordtheforceversustime; loadthetestspec
