ASTM-D1621-2010

Designation:D1621–10StandardTestMethodforCompressivePropertiesofRigidCellularPlastics1ThisstandardisissuedunderthefixeddesignationD1621;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope*1.1Thistestmethoddescribesaprocedurefordeterminingthecompressivepropertiesofrigidcellularmaterials,particu-larlyexpandedplastics.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesinparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThistestmethodandISO844aretechnicallyequivalent.2.ReferencedDocuments2.1ASTMStandards:2D618PracticeforConditioningPlasticsforTestingE4PracticesforForceVerificationofTestingMachinesE83PracticeforVerificationandClassificationofExten-someterSystemsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod2.2ISOStandard:ISO844CellularPlastics—CompressionTestofRigidMa-terials33.Terminology3.1Definitions:3.1.1compliance—thedisplacementdifferencebetweentestmachinedrivesystemdisplacementvaluesandactualspecimendisplacement.3.1.2compliancecorrection—ananalyticalmethodofmodifyingtestinstrumentdisplacementvaluestoeliminatetheamountofthatmeasurementattributedtotestinstrumentcompliance.3.1.3compressivedeformation—thedecreaseinlengthpro-ducedinthegagelengthofthetestspecimenbyacompressiveloadexpressedinunitsoflength.3.1.4compressivestrain—thedimensionlessratioofcom-pressivedeformationtothegagelengthofthetestspecimenorthechangeinlengthperunitoforiginallengthalongthelongitudinalaxis.3.1.5compressivestrength—thestressattheyieldpointifayieldpointoccursbefore10%deformation(asinFig.1a)or,intheabsenceofsuchayieldpoint,thestressat10%deformation(asinFig.1b).3.1.6compressivestress(nominal)—thecompressiveloadperunitareaofminimumoriginalcrosssectionwithinthegageboundaries,carriedbythetestspecimenatanygivenmoment,expressedinforceperunitarea.3.1.7compressivestress-straindiagram—adiagraminwhichvaluesofcompressivestressareplottedasordinatesagainstcorrespondingvaluesofcompressivestrainasabscis-sas.3.1.8compressiveyieldpoint—thefirstpointonthestress-straindiagramatwhichanincreaseinstrainoccurswithoutanincreaseinstress.3.1.9deflectometer—adeviceusedtosensethecompres-sivedeflectionofthespecimenbydirectmeasurementofthedistancebetweenthecompressionplatens.3.1.10displacement—compressionplatenmovementaftertheplatenscontactthespecimen,expressedinmillimetresorinches.3.1.11gagelength—theinitialmeasuredthicknessofthetestspecimenexpressedinunitsoflength.1ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlasticsandisthedirectresponsibilityofSubcommitteeD20.22onCellularMaterials-PlasticsandElastomers.CurrenteditionapprovedApril1,2010.PublishedApril2010.Originallyapprovedin1959.Lastpreviouseditionapprovedin2004asD1621-04a.DOI:10.1520/D1621-10.2ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,4thFloor,NewYork,NY10036,*ASummaryofChangessectionappearsattheendofthisstandard.Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.3.1.12modulusofelasticity—theratioofstress(nominal)tocorrespondingstrainbelowtheproportionallimitofamaterialexpressedinforceperunitareabasedontheminimuminitialcross-sectionalarea.3.1.13proportionallimit—thegreateststressthatamaterialiscapableofsustainingwithoutanydeviationfrompropor-tionalityofstress-to-strain(Hooke’slaw)expressedinforceperunitarea.4.SignificanceandUse4.1Thistestmethodprovidesinformationregardingthebehaviorofcellularmaterialsundercompressiveloads.Testdataisobtained,andfromacompleteload-deformationcurveitispossibletocomputethecompressivestressatanyload(suchascompressivestressatproportional-limitloadorcompressivestrengthatmaximumload)andtocomputetheeffectivemodulusofelasticity.4.2Compressiontestsprovideastandardmethodofobtain-ingdataforresearchanddevelopment,qualitycontrol,accep-tanceorrejectionunderspecifications,andspecialpurposes.Thetestscannotbeconsideredsignificantforengineeringdesigninapplicationsdifferingwidelyfromtheload-timescaleofthestandardtest.Suchapplicationsrequireadditionaltestssuchasimpact,creep,andfatigue.4.3Beforeproceedingwiththistestmethod,referenceshallbemadetothespecificationofthematerialbeingtested.Anytestspecimenpreparation,conditioning,dimensions,ortestingparameters,oracombinationthereof,coveredinthematerialsspecificationshalltakeprecedenceoverthosementionedinthi