【英文标准名称】:Plastics—Determinationofflexuralproperties
【原文标准名称】:塑料.弯曲性能测定
【标准号】:ISO178-2010
【标准状态】:现行
【国别】:国际
【发布日期】:2010-12-15
【实施或试行日期】:2010-12-15
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC61
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:Bendtesting;Bendingstiffness;Bendingstrength;Conditioning;Conditioningclimate;Definitions;Determination;Flexibility;Flexuralcreep;Flexuralstrength;Interpretations;Materialtestingmachines;Materialstesting;Mathematicalcalculations;Plastics;Polymers;Precision;Rigid;Testatmospheres;Testequipment;Testspecimens;Testing;Thermoplasticpolymers;Thermosettingpolymers;Three-pointloading
【摘要】:1.1ThisInternationalStandardspecifiesamethodfordeterminingtheflexuralpropertiesofrigid(see3.12)andsemi-rigidplasticsunderdefinedconditions.Astandardtestspecimenisdefined,butparametersareincludedforalternativespecimensizesforusewhereappropriate.Arangeoftestspeedsisincluded.1.2Themethodisusedtoinvestigatetheflexuralbehaviourofthetestspecimensandtodeterminetheflexuralstrength,flexuralmodulusandotheraspectsoftheflexuralstress/strainrelationshipundertheconditionsdefined.Itappliestoafreelysupportedbeam,loadedatmidspan(three-pointloadingtest).1.3Themethodissuitableforusewiththefollowingrangeofmaterials:?thermoplasticmoulding,extrusionandcastingmaterials,includingfilledandreinforcedcompoundsinadditiontounfilledtypes;rigidthermoplasticssheets;?thermosettingmouldingmaterials,includingfilledandreinforcedcompounds;thermosettingsheets.InagreementwithISO10350-1[5]andISO10350-2[6],thisInternationalStandardappliestofibre-reinforcedcompoundswithfibrelengthsu7,5mmpriortoprocessing.Forlong-fibre-reinforcedmaterials(laminates)withfibrelengths>7,5mm,seeISO14125[7].Themethodisnotnormallysuitableforusewithrigidcellularmaterialsorsandwichstructurescontainingcellularmaterial.Insuchcases,ISO1209-1[3]and/orISO1209-2[4]canbeused.NOTEForcertaintypesoftextile-fibre-reinforcedplastic,afour-pointbendingtestispreferred.ThisisdescribedinISO14125.1.4Themethodisperformedusingspecimenswhichmaybeeithermouldedtothespecifieddimensions,machinedfromthecentralsectionofastandardmultipurposetestspecimen(seeISO20753)ormachinedfromfinishedorsemi-finishedproducts,suchasmouldings,laminates,orextrudedorcastsheet.1.5Themethodspecifiesthepreferreddimensionsforthetestspecimen.Testswhicharecarriedoutonspecimensofdifferentdimensions,oronspecimenswhicharepreparedunderdifferentconditions,canproduceresultswhicharenotcomparable.Otherfactors,suchasthetestspeedandtheconditioningofthespecimens,canalsoinfluencetheresults.NOTEEspeciallyforsemi-crystallinepolymers,thethicknessoftheorientedskinlayer,whichisdependentonthemouldingconditions,alsoaffectstheflexuralproperties.1.6Themethodisnotsuitableforthedeterminationofdesignparametersbutcanbeusedinmaterialstestingandasaqualitycontroltest.1.7Formaterialsexhibitingnon-linearstress/strainbehaviour,theflexuralpropertiesareonlynominal.Theequationsgivenhavebeenderivedassuminglinearelasticbehaviourandarevalidfordeflectionsofthespecimenthataresmallcomparedtoitsthickness.Withthepreferredspecimen(whichmeasures80mm×10mm×4mm)attheconventionalflexuralstrainof3,5%andaspan-to-thicknessratio,L/h,of16,thedeflectionis1,5h.Flexuraltestsaremoreappropriateforstiffandbrittlematerialsshowingsmalldeflectionsatbreakthanforverysoftandductileones.1.8ContrarytothepreviouseditionsofthisInternationalStandard,thiseditionspecifiestwomethods,methodAandmethodB.MethodAisidenticaltothemethodinpreviouseditionsofthisInternationalStandard,i.e.itusesastrainrateof1%/minthroughoutthetest.MethodBusestwodifferentstrainrates:1%/minforthedeterminationoftheflexuralmodulusand5%/minor50%/min,dependingontheductilityofthematerial,forthedeterminationoftheremainderoftheflexuralstress-straincurve.
【中国标准分类号】:
【国际标准分类号】:83_080_01
【页数】:24P.;A4
【正文语种】:英语