1、Designation: F 1805 06Standard Test Method forSingle Wheel Driving Traction in a Straight Line on Snow-and Ice-Covered Surfaces1This standard is issued under the fixed designation F 1805; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. 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 test method covers a procedure for measuring thedriving traction of passenger car and light tru
3、ck tires whiletraveling in a straight line on snow- or ice-covered surfaces.1.2 This test method utilizes a dedicated, instrumented,four-wheel rear-wheel drive test vehicle with a speciallyinstrumented drive axle to measure fore-aft and vertical forcesacting on a single driven test tire.1.3 This tes
4、t method is suitable for research and develop-ment purposes where tires are compared during a single seriesof tests. They may not be suitable for regulatory statutes orspecification acceptance because the values obtained may notnecessarily agree or correlate either in rank order or absolutetraction
5、performance level with those obtained under otherenvironmental conditions on other surfaces or the same surfaceafter additional use.1.4 The values stated in SI units are to be regarded as thestandard. Ordinarily, N and kN should be used as units of force.This standard may utilize kgf as a unit of fo
6、rce in order toaccommodate the use of load and pressure tables, as found inother standards both domestic and global that are commonlyused with this standard. The values given in parentheses are forinformation only.1.5 This standard does not purport to address all of thesafety concerns, if any, assoc
7、iated 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:2E 1136 Specification for A Radial Standard Reference TestT
8、ireF 377 Practice for Calibration of Braking/Tractive Measur-ing Devices for Testing TiresF 538 Terminology Relating to the Characteristics and Per-formance of TiresF 1046 Guide for PreparingArtificially Worn Passenger andLight Truck Tires for TestingF 1572 Test Methods for Tire Performance Testing
9、on Snowand Ice SurfacesF 1650 Practice for Evaluating Tire Traction PerformanceData Under Varying Test Conditions3. Terminology3.1 Definitions:3.1.1 candidate tire, na test tire that is part of a testprogram. F 5383.1.1.1 DiscussionThe term “candidate object” may beused in the same sense as candidat
10、e tire.3.1.2 control tire, na reference tire used in a specifiedmanner throughout a test program. F 5383.1.2.1 DiscussionAcontrol tire may be of either type andtypical tire use is the reference (control) tire in Practice F 1650that provides algoritms for correcting (adjusting) test data forbias tren
11、d variations (See Practice F 1650).3.1.3 driving coeffcient (nd), nthe ratio of the drivingforce to a normal force. F 5383.1.4 driving force (F), nof a tire, the positive longitudi-nal force resulting from the application of driving torque.F 5383.1.5 grooming, vin tire testing, mechanically reworkin
12、ga snow test surface in order to obtain a surface with moreconsistent properties. F 5383.1.6 ice, dry, nsmooth ice without loose surface materi-als. F 5383.1.7 longitudinal force (F), nof a tire, the component ofthe tire force vector in the X8 direction. F 5383.1.8 longitudinal slip velocity (L/T),
13、nthe effective roll-ing radius multiplied by the difference between the spinvelocity (in rad/unit time) of a driven or braked tire and that ofa free rolling tire when each is traveling in a straight line.F 5383.1.9 reference tire, na special tire included in a testprogram; the test results for this
14、tire have significance as a basevalue or internal benchmark. F 5381This test method is under the jurisdiction of Committee F09 on Tires and is thedirect responsibility of Subcommittee F09.20 on Vehicular Testing.Current edition approved Dec. 1, 2006. Published December 2006. Originallyapproved in 19
15、97. Last previous edition approved in 2000 as F 1805 00.2For 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.1Copy
16、right ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.10 snow, hard pack, nin tire testing, packed basewithout loose snow. F 5383.1.11 snow, medium pack, nin tire testing, groomedpacked base with 2.5 to 5.0 cm (1 to 2 in.) loose snow.F 5383
17、.1.12 snow, medium hard pack, nin tire testing, packedbase with some loose snow. F 5383.1.13 snow, soft pack, nin tire testing, freshly fallen ordeeply groomed base snow with 5.0 to 7.5 cm (2 to 3 in.) loosesnow. F 5383.1.14 spin velocity, nthe angular velocity of the wheelabout its spin axis. F 538
18、3.1.15 standard reference test tire (SRTT), na tire thatmeets the requirements of Specification E 1136, commonlyused as a control tire or a surface monitoring tire. F 5383.1.16 surface monitoring tire, na reference tire used toevaluate changes in the test surface over a selected time period.F 5383.1
19、.17 test (or testing), na procedure performed on anobject (or set of nominally identical objects) using specifiedequipment that produces data unique to the object (or set).F 5383.1.17.1 DiscussionTest data are used to evaluate ormodel selected properties or characteristics of the object (or setof ob
20、jects). The scope of testing depends on the decisions to bemade for any program, and sampling and replication plans (seedefinitions below) need to be specified for a complete programdescription.3.1.18 test matrix, nin tire testing a group of candidatetires, usually with specified reference tires; al
21、l tests arenormally conducted in one testing program. F 5383.1.19 test run, na single pass of a loaded tire over a giventest surface. F 5383.1.20 test tire, na tire used in a test. F 5383.1.21 test tire set, none or more test tires, as required bythe test equipment or procedure, to perform a test, t
22、herebyproducing a single test result. F 5383.1.21.1 DiscussionThe four nominally identical tires re-quired for vehicle stopping distance testing constitute a test tireset. In the discussion below where the test tire is mentioned, itis assumed that the test tire set may be substituted for the testtir
23、e, if a test tire set is required for the testing.3.1.22 traction test, nin tire testing, a series of n test runsat a selected operational condition; a traction test is character-ized by an average value for the measured performanceparameter. F 5383.1.23 vertical load, nthe normal reaction of the ti
24、re onthe road which is equal to the negative of normal force.F 5384. Summary of Test Method4.1 These test methods describe the use of an instrumentedvehicle with a single test wheel capable of measuring the tireperformance properties under drive torque on snow and icesurfaces when traveling in a str
25、aight line.4.2 The test is conducted by driving the test vehicle over thetest surface. Driving torque is gradually increased to the testwheel while maintaining the vehicle speed by applying brakingtorque to the non-test wheels of the vehicle. The drivingtraction coefficient is determined from the me
26、asured values oflongitudinal and vertical forces over a specified slip or timerange. The recommended vehicle test speed is 8.0 km/hr(5.0 mph).5. Significance and Use5.1 This test method describes a technique for assessing theperformance characteristics of tires in a winter environment onsnow and ice
27、 surfaces. When snow is referred to hereafter, iceis implied as appropriate.5.2 The measured values quantify the dynamic longitudinaltraction properties of tires under driving torque. Dynamictraction properties are obtained on snow surfaces prepared inaccordance with the stated test procedures and a
28、ttempts toquantify the tires performance when integrated into a vehicle-environmental system. Changing any one of these environmen-tal factors will change the measurements obtained on asubsequent test run.5.3 This test method addresses longitudinal driving tractionproperties only on snow and ice sur
29、faces. Refer to TestMethods F 1572 for test methods for braking and lateraltraction properties on snow or ice, or both.6. Interferences6.1 Factors that may affect tire snow performance and mustbe considered in the final analysis of data include:6.1.1 Snow temperature,6.1.2 Ambient temperature,6.1.3
30、Mechanical breakdown of the agglomerated snow-flake into granular crystals,6.1.4 Solar load,6.1.5 Tire temperature,6.1.6 Tire wear condition (preparation),6.1.7 Tire pressure,6.1.8 Tire vertical load,6.1.9 Snow surface characteristics, and6.1.10 Rim selection.7. Apparatus7.1 The test vehicle shall h
31、ave the capability of maintainingthe specified test speed 6 0.8 km/h (6 0.5 mph) during alllevels of driving torque application.7.2 The test vehicle shall be equipped with an automaticthrottle actuator to allow the gradual increase of driving torqueat a predetermined (repeatable) rate.7.3 The test v
32、ehicle shall be a rear drive, four wheelpassenger car or a light truck less than or equal to 44.5 kN(10 000 lbf) GVW. The range of test tires and load conditionswill determine the vehicle size and selection. Utilizing a frontwheel drive test vehicle is not addressed in this standardalthough the basi
33、c procedures could be applied with appropri-ate conditional modifications.7.4 The test vehicle shall be instrumented to measurelongitudinal and vertical forces at the tire and test surfaceinterface during the application of driving torque.F18050627.5 The test vehicle shall have provisions to automat
34、icallyand completely disengage the brake on the test wheel (ifinstalled) prior to throttle application. Complete disengage-ment is necessary to eliminate all drag that might be caused bythe brake assembly.7.6 Opposite Tire:7.6.1 The tire installed opposite the instrumented test wheelshall have a suf
35、ficiently large traction coefficient to minimizeslip of this tire during the traction test. The opposite tire shouldhave a coefficient at least 50 % greater than the expectedcoefficient of the test tire. A tire chain may be utilized toincrease the traction of the opposite tire when testing on snowsu
36、rfaces.7.6.2 The opposite tire shall be selected to have an outsidediameter that is within 62.5 cm (61 in.) of that of the test tire.7.7 Asuitable ride height adjustment system on the rear axleshall be provided to permit adjustment for each tire size andload to minimize transducer crosstalk as estab
37、lished duringcalibration.7.8 InstrumentationThe test wheel position on the testvehicle shall be equipped with a wheel rotational velocitymeasuring system and with transducers to measure the dy-namic longitudinal force and vertical load at the test wheel.7.8.1 General Requirements for Measurement Sys
38、temTheinstrumentation system shall conform to the following overallrequirements at ambient temperatures between 23 and 43C(10 and 110F):7.8.1.1 Overall system accuracy, force6 1.5 % of verticalload or traction force from 450 N (100 lbf) to full scale.7.8.1.2 Overall system accuracy, speed6 1.5 % of
39、speedfrom 6.4 km/h (4.0 mph) to 48.0 km/h (30.0 mph).7.8.1.3 Shunt CalibrationAll strain-gage transducers shallbe equipped with shunt calibration resistors that can beconnected before or after test runs. The calibration signal shallbe in the range of the expected measurement for each analoguechannel
40、7.8.1.4 RuggednessThe exposed portions of the systemshall tolerate 100 % relative humidity (rain or spray) and allother adverse conditions such as dust, shock, and vibrationswhich may be encountered in regular operation.7.8.2 Vehicle SpeedVehicle forward speed (normally ob-tained from a front non-dr
41、iven wheel on the test vehicle) shallbe measured digitally with an encoder or optical system havinga minimum of 500 counts per revolution. Output shall bedirectly visible to the driver and shall be simultaneouslyrecorded. It may be necessary on a very low coefficient surface,i.e., ice, to disconnect
42、 any braking action to the wheel beingutilized for measuring vehicle speed. A separate fifth-wheelsystem may be utilized to measure vehicle forward speed.7.8.3 Test Wheel SpeedTest wheel speed shall be mea-sured digitally with an encoder or optical system having aminimum of 1000 counts per wheel rev
43、olution. The outputshall be recorded.7.8.4 Vertical LoadThe vertical load-measuring trans-ducer shall measure the vertical load at the test wheel duringdriving torque application. The transducer full scale range shallbe in excess of the dynamic loading during a test. Data pointsshall be evaluated to
44、 ensure dynamic loading is within thecalibrated range of the transducer. The static load should beless than 80 % of the calibrated range. The transducer designand location shall minimize inertial effects and vibration-induced mechanical resonance. The transducer shall have anoutput directly proporti
45、onal to the force with less than 1 %hysteresis and less than 1 % nonlinearity at full scale. It shallhave less than 2 % cross-axis sensitivity at full scale. Thetransducer shall be installed in such a manner as to experienceless than 1 angular rotation with respect to its measuring axesat a maximum
46、expected driving torque. The transducerstypically have a minimum full scale range of 0 to 8.9 kN(2000 lbf).7.8.5 Driving Traction ForcesThe driving traction force-measuring transducers shall measure longitudinal force gener-ated at the tire-road interface as a result of driving torqueapplication wit
47、h a full scale range of at least 100 % of theapplied static vertical load. Otherwise, the transducers shallhave the same specifications as those described in 7.8.4.7.8.6 Signal Conditioning and Recording SystemAll sig-nal conditioning and recording equipment shall provide linearoutput with necessary
48、 gain and reading resolution to meet therequirements of 7.8.1. Additionally, it shall have the followingspecifications:7.8.6.1 Minimum Frequency Responseflat from dc to 18Hz, within 61%,NOTE 1Based on a study of a sample acquisition and force transducersystem, a resonant frequency of 20 Hz was measu
49、red.7.8.6.2 Signal-to-Noise Ratioat least 20/1,7.8.6.3 Gain shall be sufficient to permit full-scale displayfor full-scale input signal level,7.8.6.4 Input impedance shall be at least ten times largerthan the output impedance of the signal source,7.8.6.5 The system must be insensitive to vibrations, accel-eration, and changes in ambient temperature. The error inreading shall not exceed 1 % full scale when subjected tovibration acceleration of 49.0 m/s2(5 gs) in the 0.5 to 40 Hzfrequency range and operating temperature range from 23 to4
