1、Designation: F3189 17Standard Test Method forMeasuring Force Reduction, Vertical Deformation, andEnergy Restitution of Synthetic Turf Systems Using theAdvanced Artificial Athlete1This standard is issued under the fixed designation F3189; the number immediately following the designation indicates the
2、 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 test method specifies a method for measuring f
3、orcereduction, vertical deformation, and energy restitution of syn-thetic turf surfaces.1.2 This method is used to characterize properties of syn-thetic turf systems including the turf fabric, infill material, andshock pad (if applicable).1.3 It can be used for characterizing synthetic turf systemsi
4、n laboratory environment or in the field.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th
5、e user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 energy restitution (ER), na measure of the energyreturned by the synthetic turf
6、 surface after the impact force hasbeen applied.2.1.2 energy restitution coeffcient, nthe ratio of the dy-namic load energy applied to the surface to the energy returnedby the surface.2.1.3 force reduction (FR), nthe ability of a synthetic turfsports surface to reduce the impact force of a mass fall
7、ing ontothat surface.2.1.3.1 DiscussionThe reduction in impact force for thistest method is expressed as a percentage reduction whencompared to a reference force of 6760 N. The reference forceis the theoretical maximum impact force that occurs when thetest is performed on a rigid surface (concrete).
8、2.1.4 synthetic turf system, nall components of the syn-thetic turf surface and subsurface that have the potential toinfluence the dynamic properties of the surface.2.1.4.1 DiscussionThese include any shock pads or dy-namic base constructions installed as part of the synthetic turfsystem.2.1.5 verti
9、cal deformation (Def), na measure of the dis-tance a test foot penetrates into the surface when a standardimpact force is applied.2.2 Symbols:2.2.1 Aacceleration in m/s2.2.2.2 Defdeformation in millimeters.2.2.3 Eenergy in Joules.2.2.4 ERenergy restitution.2.2.5 Fforce in Newtons.2.2.6 FRforce reduc
10、tion in %.2.2.7 gacceleration due to gravity.2.2.8 Rcoefficient of restitution.2.2.9 ttime in seconds.3. Summary of Test Method3.1 A mass with a spring attached is allowed to fall onto thetest surface. The acceleration of the mass is recorded from themoment of release until after its impact with the
11、 turf surface.Force Reduction is the percentage reduction in the measuredmaximum force (Fmax) relative to the reference force (Fmax).3.2 Deformation is calculated by double integration of therecord of acceleration versus time. Energy restitution is calcu-lated from the force versus deformation curve
12、.4. Significance and Use4.1 The dynamic interaction between the athlete and thesynthetic turf surface affects the comfort and the performanceof the athlete. Interaction with a surface that has low amountsof deformation and shock absorption allows the player to runfast and turn quickly, but has the p
13、otential to cause discomfortand damage to the lower extremity joints. Synthetic turf1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility ofSubcommittee F08.65 on Artificial Turf Surfaces and Systems.Cu
14、rrent edition approved Jan. 1, 2017. Published February 2017. DOI: 10.1520/F3189-17.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on s
15、tandardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1surfaces having high deformation have lower energy restitu-tion. Less of the energy e
16、xerted by the athlete returns from thesurface, possibly increasing the fatigue for the performingathlete.5. Test Conditions5.1 Laboratory Test Conditions:5.1.1 Laboratory tests shall be conducted on samples of thecomplete turf system. The test sample shall have nominaldimensions of 1 m by 1 m. The t
17、urf samples shall be preparedin accordance with the manufacturers stated method.5.1.2 Characteristics of the Laboratory FloorThe labora-tory floor shall be concrete with a minimum thickness of 100mm.5.1.3 Conditioning and Test TemperatureThe test pieceshall be conditioned at laboratory temperature (
18、23 6 2C) for24 6 0.5 h.5.2 Field Test ConditionsTesting in the field shall beperformed at ambient temperature and humidity which shall berecorded and reported.6. Test Apparatus6.1 The principle of the test apparatus is shown in Fig. 1 andconsists of the following essential components specified in 6.
19、2 6.7.6.2 Falling mass (3), incorporating a helical metal spring (5)and steel foot (6) and fitted with an accelerometer (4), havinga total mass of 20.0 6 0.1 kg.6.3 Helical steel spring (5), whose characteristic is linear(measured with maximum increments of 1000 N) with a springrate of 2000 6 60 N/m
20、m over the range of 0.1 to 7.5 kN. Theaxis of the spring shall be vertical and shall be directly belowthe center of gravity of the falling mass. The spring shall havethree coaxial coils that shall be rigidly fixed together at theirends. The mass of the spring shall be 0.80 6 0.05 kg.6.4 Steel test f
21、oot (6) having a lower side rounded to aradius of 500 6 50 mm; an edge radius of 1 mm; a diameter of70 6 1 mm and a minimum thickness of 10 mm. The mass ofthe test foot shall be 400 6 50 g.6.5 Test frame with minimum of three adjustable supportingfeet, no less than 250 mm from the point of applicati
22、on of theload. The design of the supporting feet shall insure the weightof the test apparatus is equally distributed on all of the feet.6.5.1 The pressure (with the mass) on each foot shall be0.003 N/mm2.6.5.2 The complete system will have a mass of 50 kg.6.6 A piezo-resistive accelerometer (4) with
23、 the followingcharacteristics:Keys:1 guide for the falling mass2 electric magnet3 falling mass4 accelerometer5 spring6 test footFIG. 1 Test ApparatusF3189 172(1) measuring range: 6 50 g;(2) 3 dB upper frequency response: 1 kHz;(3) linearity error2%.6.6.1 The accelerometer shall be firmly attached to
24、 avoidnatural filtering and the generation of spurious signals.6.7 Means of supporting the mass (2) that allows the fallingheight to be set with an uncertainty of no greater than 0.25 mm.6.8 Means of conditioning and recording the signal from theacceleration sensing device and a means of displaying
25、therecorded signal (see Fig. 2).6.8.1 Sampling rate minimum: 9600 Hz;6.8.2 ElectronicA-D converter with a resolution giving 1 bitequal to a maximum 0.005 g acceleration;6.8.3 Signal from the acceleration sensing device shall befiltered with a 2nd order low-pass Butterworth filter with acut-off frequ
26、ency of 600 Hz.6.9 Means of calculating the speed and displacement of thefalling weight during the course of impact by integration anddouble integration of the acceleration signal. To be verified inaccordance with 7.4 and 7.5.7. Verification of Impact Speed7.1 GeneralThe verification is carried out
27、to ensure thecorrect impact speed (or energy, because the mass is fixed) andthe correct functioning of the apparatus. The checking proce-dure shall consist of three steps and shall be carried out on astable and rigid floor (no significant deflection under a 5kg/cm2pressure) as follows:7.1.1 Laborato
28、ry TestingAt least once on any day onwhich testing is undertaken or following dismantling andre-assembly of the test apparatus, prior to carrying out anymeasurements7.1.2 Site TestingFollowing re-assembly of the testapparatus, prior to carrying out any measurements.7.2 Set up the apparatus to ensure
29、 a free drop that is no morethan 61 from the vertical. Adjust the height of the lower faceof the steel test foot so it is 55.00 6 0.25 mm above the rigidfloor. Drop the weight on the rigid floor and record theacceleration of the falling weight until the end of the impact.7.3 Repeat 7.1 twice, giving
30、 a total of 3 impacts.7.4 For each impact calculate, by integration from T0 to T1of the acceleration signal, the initial impact velocity. Calculatethe mean impact velocity of the three recordings. The meanimpact velocity shall be in the range of 1.02 m/s and 1.04 m/s.If the initial impact velocity i
31、s outside the specified range, thetest apparatus is not operating correctly and any subsequentresults obtained shall be considered invalid.FIG. 2 Example of Falling Mass Acceleration Versus Time Curvewhere:T0 = time when the mass starts to fall.T1 = time when the test foot makes initial contact with
32、 the surface (determined on the Velocity/time curve Vmax*)T2 = time (determined on the Velocity/time curve Vmin*) corresponding to the maximum velocity when the mass reboundsafter the impact.NOTE 1Vmin can be a minimum or maximum value depending on the sensors direction.F3189 1737.5 After verifying
33、the initial impact velocity, place thefalling weight on the rigid floor. Measure the height between astatic reference point on the apparatus (for example, themagnet) and the falling weight. The measured height shall beused for all measurements and is designated the “lift height”.NOTE 1The “lift heig
34、ht” will be slightly greater than 55.0 mm due tothe deflection of the apparatus during operation.8. Checking of Force on Concrete8.1 At a frequency of at least once every 3 months check theforce on the laboratory concrete floor to ensure the consistencyof maximum force on concrete as measured by the
35、 apparatusand the theoretical force on concrete (6760 N 6 250 N).9. Test Procedure9.1 GeneralTo avoid influence of the operators weight onthe results, through variation in the preload on the sportssurface system under test, the operator shall be positioned:9.1.1 Laboratory TestOff the sample.9.1.2 F
36、ield TestAt least 1 m from the point of impact.9.2 Test Method:9.2.1 Set the apparatus so it is positioned vertically on thetest sample.9.2.2 Lower the test foot smoothly onto the surface of thetest piece. Immediately after (within 10 s) set the “lift height”described in 7.5 and reattach the mass on
37、 the magnet.9.2.3 After 30 (65) s (to allow the test specimen to relaxafter removal of the test mass) drop the mass and record theacceleration signal.9.2.4 Re-validate the lift height after the impact so thatwithin 30 6 5 s the mass is lifted from the surface andre-attached to the magnet.9.2.5 Repea
38、t 9.2.4 and 9.2.5 to obtain a total of 3 impacts.9.3 Calculation of Force Reduction and Expression ofResults:9.3.1 Calculate the maximum force (Fmax) at the impactwith the following formula:Fmax5 m 3 Amax1 g! (1)where:Fmax= peak force, expressed in Newtons (N);Amax= peak acceleration during the impa
39、ct (ms2);m = calibrated mass of the falling weight (kg); andg = the acceleration due to gravity (ms2).9.3.2 Calculate the Force Reduction (FR) with the followingformula:FR 5F1 2Fmax6760G3100 (2)where:FR = force reduction, %, andFmax= peak force measured on the synthetic turf surface(N).9.3.3 Report
40、the value of Force Reduction as the mean ofthe second and third drops in the same location to the nearest1 %, for example, 60 %.9.4 Calculation of Deformation and Expression of Results:9.4.1 Calculate by double integration of a(t) on the intervalT1, T2 the displacement of the weight Dweight (t), sta
41、rting atthe moment where it has reached its highest velocity (at T1).(See Fig. 3.) The vertical deformation is defined (on the timeinterval T1, T2) as:VD 5 Dweight2 Dspring(3)where:Dweight= max *T1T2*T0T2Adtdt#, with Dweight=0matT1,andDspring=m 3 Amax!CspringFIG. 3 Example of Velocity Versus Time Cu
42、rveF3189 174where:Amax= peak acceleration during the impact (9.81 ms2),m = the calibrated mass of the falling weight (kg), andCspring= spring constant (given in the certificate of calibra-tion and measured in the adapted range).9.4.2 Report the value of Vertical Deformation as the meanof the second
43、and third drops to the nearest 0.1 mm, forexample, 6.6 mm.9.5 Calculation of Energy of Restitution and Expression ofResults:9.5.1 Draw the curves F(t) and Def(t) using a(t).where:F(t) = measured force on the surface versus time;Def(t) = deformation of the surface versus time;a(t) = acceleration sign
44、al from the sensor versus time.9.5.2 On the same time base, draw the curve F(Def) (seeFig. 4).9.5.3 Calculate:9.5.3.1 The impact energy by the formula:Ei5 *Def0DefmaxFDef!Def initial condition Def0 5 0m (4)9.5.3.2 The restituted energy with the formula:Er 5 *DefmaxDefresidualFDef!Def (5)9.5.3.3 The
45、coefficient of restitution, R, with the formula:R 5ErEi(6)9.5.4 Expression of ResultsReport the R value as the meanof the second and third drops in percentage to the nearest 1 %,for example, 34 %.10. Report10.1 Provide a full description of the synthetic turf system(including shock pad if applicable
46、).10.2 For laboratory testing, report the temperature andrelative humidity of the laboratory conditions.10.3 For field testing, report the ambient temperature, sur-face temperature, and the relative humidity.10.4 Report the Force Reduction, Vertical Deformation, andEnergy of Restitution for the lab
47、sample tested. For fieldtesting, report the three performance values for each pointtested.11. Precision and Bias11.1 Round robin testing to determine the precision of thismethod is being planned and the data will be available by theend of 2017.12. Keywords12.1 advanced artificial athlete; energy res
48、titution; forcereduction; synthetic turf performance; vertical deformationF3189 175APPENDIXX1. SPORTS GOVERNING BODIES HAVING SPECIFICATIONS UTILIZING THE ADVANCED ARTIFICIAL ATHLETEX1.1 Sport governing bodies such as FIFA (soccer), WorldRugby (rugby), and FIH (field hockey) have establishedperforma
49、nce for synthetic turf that will be used in matches ortournaments sanctioned by the governing body. The require-ment documents for those sports are listed in references.RELATED MATERIALFIFA Quality Concept for Football Turf Handbook of Requirements(Most currentWorld Rugby Regulation 22FIH Handbook of Performance, Durability, and Construction Require-ments for Synthetic Turf Hockey Pitches, (Most current version)ASTM International takes no position respecting the validity of any patent rights asserted in connection with any i
