1、Designation: F355 09An American National StandardStandard Test Method forImpact Attenuation of Playing Surface Systems andMaterials1This standard is issued under the fixed designation F355; the number immediately following the designation indicates the year of originaladoption or, in the case of rev
2、ision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of certainshock-absorbing characteristics, the impact force
3、-time relation-ships, and the rebound properties of playing surface systems.This test method is applicable to natural and artificial playingsurface systems and to components thereof. Typical playingsurfaces are wrestling mats, football fields, soccer fields,playgrounds, and so forth.NOTE 1This test
4、method may also be used to measure the shock-attenuation properties of materials used as protective padding, such as thepadding on trampoline frames, football goal posts, gymnasium wall,shoulder pads, body padding, and so forth. It should not be used, withoutsome modifications, to test the finished
5、products.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 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 esta
6、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1596 Test Method for Dynamic Shock Cushioning Char-acteristics of Packaging MaterialE105 Practice for Probability Sampling Of MaterialsE1
7、22 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF1292 Specification for Impact Attenuation of SurfacingMaterials Within the
8、 Use Zone of Playground EquipmentF2650 Terminology Relating to Impact Testing of SportsSurfaces and Equipment2.2 SAE Standard:SAE J211/1 Instrumentation for Impact Tests - Part 1 -Electronic Instrumentation (rev. July 2007)33. Terminology3.1 Definitions:3.1.1 Definitions of terms related to impact t
9、esting of sportssurfaces equipment can be found in Terminology F2650.4. Summary of Test Method4.1 A test specimen is impacted at a specified velocity witha missile of given mass and geometry. An accelerometermounted in the missile is used to record the acceleration-timehistory of the impact and the
10、peak acceleration is used as ameasure of impact severity. Optionally, the displacement his-tory of the impact may also be recorded.4.2 This test method defines three missiles for use in playingsurface impact tests:4.2.1 Missiles A and D are both cylindrical, with specifiedmass and geometry and a cir
11、cular, flat, metal impactingsurface. These missiles are used with a guidance mechanism.4.2.2 Missile E has a hemispherical impacting surface ofspecified mass and geometry and may be used with a guidancesystem or, if equipped with a triaxial accelerometer, withoutguidance (“free-fall”).4.2.3 The spec
12、ific masses and geometries of the missiles aredetailed in 6.2.5. Significance and Use5.1 The results of this method quantify the impact attenua-tion of playing surface and system specimens under the specifictest conditions.5.2 The test method measures the outcome of impactsperformed under specific c
13、onditions. It does not quantify theintrinsic material properties of the tested specimens.5.3 Test results from different specimens obtained under thesame conditions (that is, the same missile mass and geometry,1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment and F
14、acilities and is the direct responsibility of Subcommittee F08.52 onMiscellaneous Playing Surfaces.Current edition approved Nov. 15, 2009. Published December 2009. Originallyapproved in 1972. Last previous edition approved in 2001 as F355 01. DOI:10.1520/F0355-09.2For referenced ASTM standards, visi
15、t 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.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/ww
16、w.sae.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.drop height, etc.) may be used to compare impact attenuationunder those conditions.5.4 Test results obtained under different conditions are notcomparable. Specifically obtaine
17、d with different missiles arenot equivalent and cannot be directly compared. Similarly, testresults obtained using the same missile, but using differentdrop heights, are not directly comparable.6. Apparatus6.1 Testing MachineAny type of dynamic testing appara-tus that impacts the test material on a
18、massive, rigid anvil witha missile at a prescribed impact velocity and monitors andrecords the acceleration-time history is acceptable. The anvilmass (impacted base) should be at least 100 times that of themissile. The test apparatus may optionally be designed to testa playing surface in-place. In e
19、ither case, the test specimenshall have dimensions larger than the impact area of the missileas specified in 7.1. The test machine and missile shall havesufficient rigidity to eliminate undesirable vibrations in theapparatus that might be recorded on the acceleration-timecurve.6.2 MissileThe missile
20、 shall be designed to meet thegeneral requirements of 4.2.1 and 4.2.2. Provision shall bemade such that the accelerometer can be securely fastenedwithin 65 of the vertical axis of the missile. The mass andgeometry for each procedure is referenced in Table 1.6.3 Recording EquipmentThe recording equip
21、ment shallmeet the following criteria:6.3.1 Acceleration-TimeThe selection of the specificacceleration-time recording equipment, including transducersand recorders, is optional. However, the recording system shallhave a frequency response adequate to measure the peakacceleration value to an accuracy
22、 of 65 % of the true value.The total system, detection and recording, shall be capable ofmeasuring impulses up to 500 g at frequencies from 20 to 1000Hz to an accuracy of 65 %. The minimum system samplingrate required is 20 000 Hz or 20 000 samples/s. The accelera-tion transducer system shall comply
23、 with the requirements ofSAE J211/1 for a channel frequency Class 1000 data channel.A low pass filter having a 4-pole Butterworth transfer functionand a corner frequency of 1650 Hz meets this requirement. Adigital filter complient withAppendix C of SAE J211/1 may besubstituted.NOTE 2Since impact tes
24、t data may have high-frequency componentsabove 1000 Hz, analog filtering should be used before sampling in orderto prevent aliasing errors in the sampling process.6.3.2 Impact and Rebound VelocitiesThe dynamic testequipment must have means of recording the impact velocitiesof the missile to an accur
25、acy of 65 % of the true value. Anymethod that does not physically interfere with the impact andgive erroneous acceleration-time results is acceptable.6.3.3 Displacement TimeIt is optional, but desirable, thatthe displacement-time history also be recorded. Any methodthat provides a linear signal prop
26、ortional to displacement alongthe impact axis which can be monitored coincidentally with theacceleration-time trace is acceptable. If displacement is re-corded, the test equipment shall have means to determine andrecord the top plane (baseline) of the playing surface systemfrom which total penetrati
27、on is determined (see TerminologyF2650).6.3.4 In the event that a means is available for accuratelydetermining both the impact and rebound velocities, it ispossible to perform two time integrations to yield thedisplacement-time history. The initial and final conditions onthe velocity can be used as
28、a check on the integral ofdeceleration that yields the velocity-time record. If the integra-tion that yields the velocity yields initial and final velocitiesthat agree with the directly measured values of these param-eters then the displacement-time history should also be able tobe accurately determ
29、ined by using the same integration methodTABLE 1 Mass and Geometry of MissilesProcedure Weight GeometryA9.1kg6 50g(206 0.11 lb) 129 6 2.0-cm2(20 6 1.0-in.2) facewith a circumference-relieved radiusof 2 6 0.25 mm (0.08 6 0.01 in.) toeliminate sharp edgesB6.8kg6 50g(156 0.011 lb) radius of 82.6 6 2.5m
30、m(3.26 0.01in.)C5.0kg6 50g(116 0.011 lb) specified in Fig. 1NOTE 1All dimensions in inches (1 in. = 25.4 mm).FIG. 1 Contour Dimensions of Test Headform for Procedure CF355 092on the velocity-time record and using 0 as the initial value ofdisplacement (once the baseline has been properly deter-mined)
31、.7. Test Specimen7.1 Test specimens shall represent the playing surface orprotective padding as it is intended to be used. The minimumdistance between the outer dimension of the missile and theedge of the specimen shall be at least 25.4 mm (1 in.) and noless than the thickness of the specimen.8. Num
32、ber of Specimens8.1 The number of specimens tested as a sample can varywidely, depending upon the intended use of the data. It isrecommended that at least two specimens be tested for each setof conditions. To obtain a specific quality assurance level, thesampling procedures of Practices E105 and E12
33、2 should befollowed.9. Conditioning9.1 Do not stack the specimens during any conditioning.They shall be under the intended use condition or precondi-tioned at 50 6 2 % relative humidity and 23 6 2C for aminimum of 4 h, or until desired temperature is attained.Samples to be tested at other than these
34、 conditions shall bestored in the desired environment for at least 4 h, or until theyreach the desired temperature, before testing. Samples shall betested (that is, impacted) within 10 s after removal from theenvironmental chamber. Samples shall be returned to theenvironmental chamber within 20 s af
35、ter impact and stored forat least 2 h between drops. Testing at other than ambientprecludes conducting successive drops at short time intervals.NOTE 3Due to differing thermal conductivities and the extreme timedependence of temperature profiles in most materials exposed to extremesurface temperature
36、 changes there may be variability introduced by thistype of testing.10. Procedure10.1 Prewarm the recording equipment as recommended bythe manufacturer. Calibrate G time and penetration-time re-corder in accordance with the recommended procedure of theequipment manufacturer.10.2 Place the specimen u
37、nder the missile, or orient thedynamic test equipment over the playing surface system.10.3 Determine the baseline by preloading the test specimento 6.8 kPa (1.0 psi) for Procedure A and adjusting the recorderto read zero penetration. When testing at other than ambientconditions, determine the baseli
38、ne with the sample at thedesired test temperature.NOTE 4When using Procedures B or C, care should be exercised tolower the missile gently onto the sample when establishing the baseline.10.4 Set the missile-propelling mechanism to obtain thedesired impact velocity.10.5 Release the missile, and record
39、 the results in accor-dance with the recommended procedures of the equipmentmanufacturers.10.6 Make three consecutive drops at intervals of 36 0.25min, unless otherwise specified (see 9.1).NOTE 5Calculation of Theoretical Drop Height: For comparison ofdata based on drop height, only the theoretical
40、drop height should be used.The following calculation should be used (see Test Method D1596):H 5 V2/2g (1)where:H = theoretical height, mm (in.),V = velocity, mm/s (in./s), andg = acceleration of gravity, 9806 mm/s/s (386 in./s/s).This calculation eliminates variations in using actual drop height, wh
41、ichmay be affected by frictional losses.11. Calculation11.1 GmaxDetermine the maximum deceleration in thetime-deceleration history to the closest G.11.2 Time to GmaxDetermine the time to maximum decel-eration to the nearest 0.05 ms.11.3 Severity IndexThe time integral of deceleration ex-ponentiated
42、2.5 times may be calculated by dividing thedeceleration-time record into equally sized time subintervals ofmagnitude of 0.05 ms and summing the deceleration values (inG) exponentiated 2.5 times between the two intersections ofthe deceleration record and the time axis. Multiply this resultby the time
43、 subinterval length (in seconds) and the result is theSeverity Index in G-s.11.4 Head Injury CriterionMore sophisticated methods ofdata integration such as the Head Injury Criterion (HIC) maybe used if desired. The HIC evolved from the Severity Indexcalculation and requires the maximization of the m
44、athematicalexpression, involving the time-average acceleration by varyingof the time interval over which the average is calculated.Numerical evaluation of the HIC requires analog-to-digitalconversion of the acceleration time profile using a samplingrate sufficient to characterize the pulse accuratel
45、y. These dataare easily processed by a digital computer. The HIC number isdetermined by evaluating the equation for all iterative combi-nations of the integration limits that the time interval allows forthe evaluation. The equation4,5for calculating the HIC value isas follows:HIC 5Ft22 t1!S1t22 t1!*
46、t1t2adtD2.5Gmax (2)A time interval of 0.05 ms should be used.11.5 Maximum PenetrationDetermine the maximum dis-placement to the nearest 0.254 mm (0.01 in.).11.6 Time to Maximum PenetrationDetermine the time tomaximum penetration.11.7 Rebound VelocityUse a straightedge to draw a tan-gent line at the
47、exit of the penetration-time trace. The slope ofthis line, multiplied by the appropriate distance and timecalibration, is the rebound velocity. Alternatively, the reboundvelocity may be determined by other velocity-measuring de-vices that measure the coefficient of restitution or percentrebound of t
48、he missile.11.8 Dynamic Hardness Index (relevant only to ProcedureA)Calculate the dynamic hardness index as follows:4Chou, C., and Nyquist, G., “Analytical Studies of the Head Injury Criterion,”Society of Automotive Engineers (SAE), Paper No. 740082, 1974.5See Specification F1292, Appendixes X1 and
49、X2.F355 093Dynamic hardness index 5Gmax3 S 3 WA 3 P(3)where:S = sample thickness, cm (in.),W = missile weight, kg (lb),A = missile area, cm2(in.2), andP = maximum penetration, cm (in.).11.9 Conformity of Data Test:11.9.1 Total sum of G values for each 0.05 ms.11.9.2 Test conformity to following relationship:|Vi| 1 |Vr| !20 000g5sumG (4)where:Vi= missile velocity at start of impact,Vr = missile velocity upon rebound from surface ofmaterial,g = acceleration of gravity units, andsumG = sum of the G values at each 0.05 ms over thetotal duration of impact.
