ASTM_F_2779_-_10.pdf

Designation:F277910Standard Practice forCommercial Radial Truck-Bus Tires to Establish EquivalentTest Severity Between a 1.707-m(67.23-in.)DiameterRoadwheel and a Flat Surface1This standard is issued under the fixed designation F2779;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 practice describes the procedure to identify equiva-lent test severity conditions between a 1.707-m diameterlaboratory roadwheel surface and a flat or highway surface forcommercial radial truck-bus tires.1.1.1 Tire operational severity,as defined as the running oroperational temperature for certain specified internal tire loca-tions,is not the same for these two test conditions.It istypically higher for the laboratory roadwheel at equal load,speed and inflation pressure conditions due to the curvatureeffect.1.1.2 The practice applies to specific operating conditions ofload range F through L for such commercial radial truck-bustires.1.1.3 The specific operating conditions under which theprocedures of the practice are valid and useful are completelyoutlined in Section 6(Limitations)of this standard.1.1.4 It is important to note that this standard is composed oftwo distinct formats:1.1.4.1 The usual text format as published in this volume ofthe Book of Standards(Vol 09.02).1.1.4.2 A special interactive electronic format that uses aspecial software tool,designated as prediction profilers orprofilers.This special profiler may be used to determinelaboratory test conditions that provide equivalent tire internaltemperatures for the tread centerline,belt edge,or ply endingregion for the two operational conditions,that is,the curvedlaboratory roadwheel and flat highway test surfaces.1.2 The prediction profilers are based on empirically devel-oped linear regression models obtained from the analysis of alarge database that was obtained from a comprehensive experi-mental test program for roadwheel and flat surface testing oftypical commercial truck and bus tires.See Section 7 andReferences(1,2)2,3for more details.1.2.1 For users viewing the standard on CD-ROM or PDF,with an active and working internet connection,the profilerscan be accessed on the ASTM website by clicking on the linksin 7.5 and 7.6.1.2.2 For users viewing the standard in a printed format,theprofilers can be accessed by entering the links to the ASTMwebsite in 7.5 and 7.6 into their internet browsers.1.3 For this standard,SI units shall be used,except whereindicated.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:4F538 Terminology Relating to the Characteristics and Per-formance of TiresF551 Practice for Using a 67.23-in.(1.707-m)DiameterLaboratory Test Roadwheel in Testing TiresIEEE/ASTM SI 10 American National Standard for Use ofthe International System of Units(SI):The Modern MetricSystem3.Terminology3.1 Definitions:3.1.1 belt edge(BE)temperature,n in the cross section ofa radial tire,the temperature at the edge of the stabilizer(working,widest)plies or belts,for example,in the rubberregion of the belt edges.1This practice is under the jurisdiction of ASTM Committee F09 on Tires and isthe direct responsibility of Subcommittee F09.30 on Laboratory(Non-Vehicular)Testing.Current edition approved April 1,2010.Published May 2010.DOI:10.1520/F2779-10.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F09-1002.4For 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 3.1.2 contained air temperature,nthe temperature of theair contained within the tire cavity when the tire is mountedand inflated on the proper rim.3.1.3 curved equivalent test severity,nin tire testing,thetest conditions(load,rotational speed,tire inflation pressure)on the flat or highway surface that will provide equivalentinternal tire temperatures,for example,at the belt edge,to aknown set of curved 1.707-m roadwheel surface test condi-tions.3.1.4 endurance,nof a tire,the ability of a tire to performas designed in its intended usage conditions such as load,inflation pressure,speed,time,and environmental conditions.3.1.5 high speed performance,nof a