Designation:F2869−10StandardPracticeforRadialLightTruckTirestoEstablishEquivalentTestSeverityBetweena1.707-m(67.23-in.)DiameterRotatingRoadwheelandaFlatSurface1ThisstandardisissuedunderthefixeddesignationF2869;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticedescribestheproceduretoidentifyequiva-lenttestseverityconditionsbetweena1.707-mdiameterlaboratoryroadwheelsurfaceandaflatorhighwaysurfaceforradialpneumaticlighttruck(LT)tires.1.1.1Tireoperationalseverity,asdefinedastherunningoroperationaltemperatureforcertainspecifiedinternaltireloca-tions,isnotthesameforthesetwotestconditions.Itistypicallyhigherforthelaboratoryroadwheelatequalload,speedandinflationpressureconditionsduetothecurvatureeffect.1.1.2ThepracticeappliestospecificoperatingconditionsoflighttrucktiresupthroughloadrangeEforsuchtiresusedonvehicleshavingagrossvehicleweightrating(GVWR)#4536kg(10000lb).1.1.3ThespecificoperatingconditionsunderwhichtheproceduresofthepracticearevalidandusefularecompletelyoutlinedinSection6,(Limitations)ofthisstandard.1.1.4Itisimportanttonotethatthisstandardiscomposedoftwodistinctformats:1.1.4.1TheusualtextformataspublishedinthisvolumeoftheBookofStandards(Vol.09.02).1.1.4.2Aspecialinteractiveelectronicformatthatusesaspecialsoftwaretool,designatedaspredictionprofilersorprofilers.Thisspecialprofilermaybeusedtodeterminelaboratorytestconditionsthatprovideequivalenttireinternaltemperaturesforthebeltedgeregionforthetwooperationalconditions,thatis,thecurvedlaboratoryroadwheelandflathighwaytestsurfaces.1.2Thepredictionprofilersarebasedonempiricallydevel-opedlinearregressionmodelsobtainedfromtheanalysisofalargedatabasethatwasobtainedfromacomprehensiveexperi-mentaltestprogramforroadwheelandflatsurfacetestingoftypicalradiallighttruck(LT)tires.SeeSection7andthere...
