ASTM_D_4482_-_11_2017.pdf

Designation:D448211(Reapproved 2017)Standard Test Method forRubber PropertyExtension Cycling Fatigue1This standard is issued under the fixed designation D4482;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of fatigue lifeof rubber compounds undergoing a tensile-strain cycle.Duringpart of the cycle,the strain is relaxed to a zero value.Thespecimens are tested without intentionally initiated flaws,cuts,or cracks.Failure is indicated by a complete rupture of the testspecimen.1.2 No exact correlation between these test results andservice is given or implied.This is due to the varied nature ofservice conditions.These test procedures do yield data that canbe used for the comparative evaluation of rubber compoundsfor their ability to resist(dynamic)extension cycling fatigue.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3767 Practice for RubberMeasurement of DimensionsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2British Standard:BS5324 Guide to Application of Statistics to Rubber Test-ing33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 extension ratiothe ratio of the extended length of aspecimen,L,to the unextended length,Lo,calculated asfollows:5LLo(1)3.1.2 fatigue life(sample)the geometric mean or medianvalue of the number of cycles required to cause failure for anumber of specimens of the sample.3.1.3 fatigue life(specimen)the total number of cyclesrequired to cause failure of a specimen,defined as a completerupture or separation of the specimen.3.1.4 strain energythe energy per unit of volume requiredto deform the specimen to the specified strain.It is measuredby the area under a stress-strain curve and expressed in kJ/m3(see Annex A1).4.Summary of Test Method4.1 The dumbbell test specimens are cyclically strained at afixed frequency and a series of fixed maximum extension ratiossuch that little or no temperature rise is induced.This cyclicalstraining action is called flexing.As a result of the flexing,cracks usually initiated by a naturally occurring flaw,grow andultimately cause failure which is defined as complete rupture ofthe test specimen.The number of cycles to failure(fatigue life)is recorded.4.2 Fatigue,as used in this test method,implies a rupturefailure mechanism that results from the growth of flaws in thespecimen.Fatigue does not refer to the drastic alteration of thephysical-chemical rubber structure characteristic of high fre-quency flexing tests that give rise to a substantial temperatureincrease.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.15on Degradation Tests.Current edition approved Oct.1,2017.Published December 2017.Originallyapproved in 1985.Last previous edition approved in 2011 as D4482 11.DOI:10.1520/D4482-11R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from British Standards Institute,2 Park St.,London W1A 2BF,United Kingdom.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 4.3 Fatigue life may be determined at each of a number ofdifferent extension ratios and the log(fatigue life)plotted as afunction of either extension-ratio or log(strain energy).Asingle extension-ratio or