1、Designation: F 538 03Standard TerminologyRelating to the Characteristics and Performance of Tires1This standard is issued under the fixed designation F 538; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This terminology primarily covers definitions for tech-nical terms that occur in ASTM Committee F09 standards onthe characteristics
3、 and performance of tires.1.2 Definitions for terms that may also be used in othertechnologies, such as vehicle behavior, are worded to coverboth areas.1.3 When any definition in this terminology (that does nothave the limiting phrase) is quoted out of context, editoriallyinsert the limiting phrase
4、in a tire after the dash following theterm. This will properly limit the field of application of theterm and definition.2. Terminology2.1 Definitions:accelerometer, nan instrument that senses inertial reactionto measure linear or angular acceleration. F811accuracy, na measurement concept that descri
5、bes the degreeof correspondence between an average measured value andan accepted reference or standard value for the object,material or phenomenon under test. F 1082aligning stiffness FL/g, nof a tire, the rate of change of tirealigning torque with respect to change in tire slip angle,usually evalua
6、ted at zero slip angle.aligning stiffness coefficient, nof a tire, the ratio of tirealigning stiffness to the tire normal force.aligning torque FL, nof a tire, the component of a tiremoment vector tending to rotate a tire about the Z8-axis,positive clockwise when looking in the positive direction of
7、the Z8-axis. F 403, F 424alignment, nthe adjustment of various parts of the vehiclessuspension system to ensure proper handling stability and tominimize abnormal tire treadwear. F 1922analysis, nan act of inspecting the S/H image and associat-ing this image with a known calibration reference. F 1364
8、anomaly, na change in the strain pattern of the rubbersurface of a straining block as a result of applied stressbrought about through a change in atmospheric pressure onthe rubber surface. F 1364anti-lock braking system (ABS), na collection of sensingand control hardware installed on a vehicle to pr
9、event wheellock-up during brake application. F 1649average tire tread depth L, nthe average of all tire groove(void) depth measurements. F 1016axle efficiency nd, nin a vehicle, the ratio of the sum of thewheel torques at the driven wheels to the product ofdriveshaft torque and axle ratio.balancing,
10、 na process to correct for heavy or light areas ofa tire and wheel assembly. F 1922bandwidth 1/ T, nthe range of frequencies within whichcertain performance characteristics occur; specific limitsnormally apply. F811bead, nof a tire, the part of a tire that comes in contact withthe rim and is shaped
11、to secure the tire to the rim. F 1922,F 1923bead separation, na breakdown of bond between tirecomponents in the bead area. F 1922belt, nin a tire, a breaker that substantially restricts thecarcass in a circumferential direction. F 1922, F 1923belt separation, na breakdown of bonding between the belt
12、sor plies or tread, or combination thereof. F 1922bias, nthe difference between the average measured testresult and the accepted reference value; it measures in aninverse manner the accuracy of a test. F 1082black sidewall, na sidewall on which only black compoundscomprise the outer visible surface
13、of the tire. F 724block, nsynonym for element. F 1426bottom out, vto deform a tire by radial load on the treaduntil radial movement of the inside surface is stopped by therim or other tire inside surface. F 414braking coefficient nd, nthe ratio of the braking force tothe normal force on a tire.braki
14、ng force F, nof a tire, the negative longitudinal forceresulting from braking torque application. F 403, F 408braking force coefficient, nof a tire, the ratio of brakingforce to normal force. F 403, F 408braking force coefficient, peak, nof a tire, the maximumvalue of tire braking force coefficient
15、that occurs prior towheel lockup as the braking torque is progressively in-creased. F 403, F 408braking force coefficient, slide, nof a tire, the value ofbraking force coefficient obtained on a locked wheel.1This terminology is under the jurisdiction of ASTM Committee F09 on Tiresand is the direct r
16、esponsibility of Subcommittee F09.94 on Terminology.Current edition approved Dec. 1, 2003. Published January 2004. Originallyapproved in 1977. Last previous edition approved in 1999 as F 538 99.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
17、d States.F 403, F 408braking torque ML2/T2, nof a vehicle, the negative wheeltorque. F 403, F 408brand, nof a tire, the name under which one or more tirelines are marketed.brand, tire, private, na brand name used by a tire seller orgroup of sellers who are not manufacturers.break, na crack or tear e
18、xtending into or through thereinforcing material. F 1922breaker, nin a tire, one or more plies under the tread regionof a tire that are additional to those which extend from beadto bead.break-in L, none or more periods of initial standardizedtire operation during which tire is brought to the state w
19、hichwill lead to more consistent test results. F 762, F 1016calibration tire, na witness tire designed to provide a fixedor known test value for selected properties. F 1806candidate tire, na test tire that is part of a test program.F 1572, F 1649, F 1650, F 1805, F 1806, F 1922candidate tire set, na
20、 set of candidate tires. F 1572,F 1649, F 1805, F 1806caravan, nfor purposes of a tire test, two or more vehiclesrunning in the same time frame, over the same test course(s),under similar but independent conditions. F 1922carcass, nof a tire, the part of a tire structure that does notinclude the tre
21、ad and sidewall rubber.casing, nof a tire, a used or treadless tire to which additionaltread rubber may be attached for the purpose of retreading.F 1922center of tire contact, nthe intersection of the wheel planeand the vertical projection of the spin axis of a wheel ontothe road plane.center rib, n
22、a rib at or near the circumferential centerline ofthe tread band. F 1426center row, na row located at or near the circumferentialcenterline. F 1426center wear, na type of irregular wear characterized by awear rate continuously increasing from shoulder to center ofthe tread band. F 1426centripetal ac
23、celeration ML2/T2, nof a vehicle, the com-ponent of the vector acceleration (of a point in a vehicle)perpendicular to the tangent of the path of the point andparallel to the road plane.chip and tear, na special type of irregular wear character-ized by a rough tread surface which may contain cracks,a
24、brasion pits or surface ruptures. F 1426circumferential line, non a tire, any real or imaginary circleon the surface of a tire, lying in a plane that is perpendicularto the spin axis. F 421, F 870clinch strip, nhigh-modulus or high-hardness compoundapplied between the carcass and the sidewall in the
25、 bead areato reinforce the bead. F 724connection point, nany point on the wheel or metal loadingplate where the resistance measuring instruments leads areconnected. F 1971control tire, na reference tire, used in a specified mannerthroughout a test program F 1572, F 1649, F 1805,F 1806, F 1922convoy,
26、 nin tire testing, two or more vehicles running at thesame time, over the same test course, under the sameinterdependent conditions. F 1922cord, nin a tire, filament(s) or plied yarns used in making atire ply. F 1922cornering force ML2/T2, nof a tire, the horizontal forceacting perpendicularly to th
27、e instantaneous motion vector ofthe center of contact for a tire operating at a slip angle.cornering force coefficient nd, nthe ratio of corneringforce to the normal force on a tire.cornering stiffness F/g, nof a tire, the negative of the rateof change of tire lateral force with respect to change in
28、 tireslip angle, usually evaluated at zero slip angle.cornering stiffness coefficient, nof a tire, the ratio of tirecornering stiffness to tire normal force.cornering traction coefficient, nthe ratio of the corneringtractive force vector and normal force.cornering traction vector angle, nthe angle b
29、etween theresultant cornering traction force vector and the X8 axis.cornering tractive force, (F), nthe vectorial sum of lateraland longitudinal tractive force components.coverstrip, na thin layer of black compound which coversthe unexposed white sidewall portion of a finished tire.F 724crazing, nmi
30、nute, closely grouped, generally superficialcracks that usually results from light activated oxidation.F 724critical slip angle, (rad or degree), nthe value of the slipangle at the peak lateral force coefficient.cross-country track, nsurface not subject to repeated trafficin addition, no roads, rout
31、es, well-worn trails or man-madeimprovements; can consist of tank trails with crushed rock orhaving large exposed obstacles (rocks, boulders, etc.).F 1922cupping, na type of irregular wear characterized by avariation in wear rate that may be periodic (essentiallycycloidally shaped) around the tread
32、band circumference inone or more rows; the variation of loss is essentiallyindependent of individual projections if the pattern containsthese projections. F 1426determination, nthe application of the complete measure-ment procedure to one piece, specimen or object to produceone numerical measured va
33、lue to be used to form an averageor median. F 1082developed footprint length L, nthe maximum footprintdimension in the circumferential direction of the tire, understated conditions of measurement. F 870developed footprint width L, nthe maximum lateraldimension of a tire footprint under stated condit
34、ions ofmeasurement. F 870diagonal wear, na type of irregular wear characterized by anincreased wear rate region or band oriented transversely(from shoulder to shoulder) at some non-90 angle withrespect to the circumferential centerline of the tread band.F 1426driving coefficient nd, nthe ratio of th
35、e driving force to thenormal force. F 424, F 1572, F 1805driving coefficient, peaknd, nthe maximum value of theF538032driving coefficient. F 424driving force, F, nof a tire, the positive longitudinal forceresulting from the application of driving torque. F 424, ,F 1572, F 1805driving torque ML2/T2,
36、nof a wheel, the positive wheeltorque. F 424effective rolling radius, nthe ratio of the linear velocity ofthe wheel center of the free rolling tire in the X8 direction tothe spin velocity. F 424element, nan isolated (totally bounded by void) projection.F 421, F 762, F 870, F 1426feathering, na type
37、of element irregular wear characterizedby thin strips of rubber extending from the edge of theelement. F 1426flange, nthat part of the rim which gives lateral support tothe tire.flex cracking, ncracking primarily caused by application ofmechanical stress-strain cycling. F 724footprint area L2, nthe
38、gross contact area of a tire that isloaded (under stated conditions) against a smooth flatsurface. F 870free rolling tire, na loaded tire rolling without applieddriving or braking torque. F 424front end breakaway, nin cornering vehicle, the point in thecurved trajectory of a vehicle when it can no l
39、onger bemaintained on its intended path because of front wheeldeparture toward the outside of the curve.g, na unit of acceleration where 1 g is equal to theacceleration of gravity, 9.8 m/s2(32.2 ft/s2). F811global testing, ntesting conducted at two or more laborato-ries or test sites for the purpose
40、 of comparing candidate tireperformance at each location for selected characteristicproperties. E 1806gravel road, ntwo lane, all-weather, occasionally main-tained, hard or loose surface (for example, large rock, paved,crushed rock, gravel) intended for medium-weight, low-density traffic, in accorda
41、nce with the U.S. Federal HighwayAdministration. F 1922grooming, vin tire testing, mechanically reworking a snowtest surface in order to obtain a surface with more consistentproperties. F 1572, F 1805groove, na void that is relatively narrow compared to itslength. F 414, F 421, F 762, F 870, F 1046,
42、 F 1426,F 1922, F 1923groove, average depth L, nthe average of all tire groovedepth measurements in a single groove.F 421, F 762, F 1016, F 1046groove (void) area L2, nthat portion of tire footprint areawhich is not contacted by ribs or elements. F 762, F 870groove (void) area fraction nd, nthe rati
43、o of the groove(void) area to the footprint area of a tire. F 870groove (void) depth L, na measurement of the perpen-dicular distance from a real or calculated reference planedefined by edges of two adjacent ribs (lugs) to the lowestpoint of contact in the groove (void). F 421, F 762,F 1046, F 1922,
44、 F 1923gyro-stabilized accelerometer, na precision vertical gyro-scope fitted with one to three accelerometers to provideorthogonal measurements referenced to the earth-fixed axissystem. F811heel-toe wear, na type of irregular wear characterized bydifferent wear rates at the leading and trailing edg
45、es of aprojection (element). F 1426ice, dry, nsmooth ice without loose surface materials.F 1572, F 1805inclination angle, nof a tire, the angle between the Z8-axisand the wheel plane. F 424inflation pressure loss rate, nrate of change of normalizedinflation pressure, determined from the slope of the
46、 linearportion of the log pressure versus time curve. F 1112inner liner, nof a tire, the innermost layer(s) of a tubelesstire that limit(s) diffusion of the inflation medium into thecarcass.intended trajectory, nthe intended or ideal path (rectilinearor curvilinear) to bring a vehicle to a stop, tha
47、t is, undercontrolled angular orientation. F 1649intermediate rib, none or more rib(s) located between thecenterline and the shoulder ribs of the tread band. F 1426intermediate row, na row located between the circumfer-ential centerline and the shoulder ribs/rows of the tread band.F 1426inter-projec
48、tion wear, na type of irregular treadwear char-acterized by different wear rates on one or more adjacentprojections (either transverse or circumferential orientation);this results in a step-off in tread depth between the adjacentprojections. F 1426intra-projection wear, na type of irregular wear cha
49、racter-ized by a different wear rate at two or more locations withina given projection. F 1426inverse wear rate nd, nthe distance traveled by a tire, afterbreak-in, per unit loss in tread depth. F 1016irregular wear, na type of treadwear characterized bysubstantial variations of tread loss both from projection toprojection and frequently from point to point on a givenprojection. F 421, F 762, F 1426juncture, nthe interface between two
