ASTM_D_6588_-_D_6588M_-_11_2016.pdf

Designation:D6588/D6588M11(Reapproved 2016)Standard Test Method forFatigue of Tire Cords(Disc Fatigue Test)1This standard is issued under the fixed designation D6588/D6588M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of fatigue oftire cords in rubber due to compression or extension,or both,using a disc fatigue tester.The fatigue is measured as a loss instrength.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in nonconformancewith the standard.1.3 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 and health practices to determine the applicabilityof regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD885 Test Methods for Tire Cords,Tire Cord Fabrics,andIndustrial Filament Yarns Made from ManufacturedOrganic-Base FibersD1776 Practice for Conditioning and Testing TextilesD6477 Terminology Relating to Tire Cord,Bead Wire,HoseReinforcing Wire,and FabricsD7269 Test Methods for Tensile Testing of Aramid Yarns3.Terminology3.1 Definitions:3.1.1 For definitions of terms relating to tire cord andfabrics,see Terminology D6477.3.1.2 For definitions of other terms related to textiles,seeTerminology D123.4.Summary of Test Method4.1 disc fatigue is a measure of the strength loss of a tirecord,which is subjected to repeated stresses.The stresses areaccomplished by subjecting the tire cords,after being cured inrubber,to repeated cycles of compression and extension.4.2 The specimen of interest is the cord after it has beenstressed and later removed from the rubber in which it wasimbedded.Cord specimens are placed between strips of rubbercompound and molded into blocks.The specimen block is thenmounted between two rotating discs that are positioned in sucha way that the specimen will undergo compression orextension,or both,as the discs rotate.After a specified numberof cycles,the cords are removed from the blocks and theirbreaking force measured on a tensile testing machine.Thefatigue,based on the unfatigued specimen strength,is ex-pressed as a percent strength loss in fatigued specimens.5.Significance and Use5.1 This test method is not recommended for acceptancetesting of commercial shipments in the absence of reliableinformation on between-laboratory precision.5.1.1 If there are differences of practical significance be-tween the reported test results for two laboratories(or more),acomparative test should be performed to determine if there is astatistical bias between them,using competent statistical assis-tance.As a minimum,test samples should be used that are ashomogeneous as possible,that are drawn from a material fromwhich the disparate test results were obtained,and that arerandomly assigned in equal numbers to each laboratory fortesting.Other fabrics with established test values may be usedfor this purpose.The test results from the two laboratoriesshould be compared using a statistical test for unpaired data,ata probability level chosen prior to the testing series.If a bias isfound,either its cause must be found and corrected,or futuretest results must be adjusted in consideration of the knownbias.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on Industrial Fibers andMetallic ReinforcementsCurrent edition approved July 1,2016.Published August 2016.Originallyapproved in 2000.Last previous edition approved in 2011 as D658811.DOI:10.1520/D6588_D6588M-11R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus,Materials,and Reagents6.1 Disc Fatigue Tester(see schematic drawing in Fig.1),with capacity for 12 specimens.For actual dimensions,seepatent US 2595069.Testers with different capacity are accept-able.6.2 Displacement Transducer,with digital readout or dialgage for setting distance between disc fatigue flanges to thenearest 0.01 mm 0.004 in.6.3 Mold,top and bottom sections with cavities in each for12 or 24 specimens with the dimensions of 10.8 by 12.7 by76.2 mm 716by12b