ASTM F429 - 10 Standard Test Method for Shock-Attenuation Characteristics of Protective Headgear for Football (Withdrawn 2017).pdf

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1、Designation: F429 10 An American National StandardStandard Test Method forShock-Attenuation Characteristics of Protective Headgearfor Football1This standard is issued under the fixed designation F429; the number immediately following the designation indicates the year of originaladoption or, in the

2、case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the shock-attenuation characteristics of protec

3、tive headgear for football.21.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 thi

4、s 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:3F717 Specification for Football Helmets2.2 SAE Document:J221 JUN 80 Instrumentation for Impact Tests, Require-ments for

5、Channel Class 100042.3 ISO Standard:ISO/DIS 6220 Headforms For Use in the Testing of Protec-tive Helmets53. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 basic planean anatomical plane that includes thesuperior rims of the auditory meatuses (the upper edges of theexternal openi

6、ngs of the ears) and the notches of the inferiororbital ridges (the bottom of the eye sockets). See Fig. 1.3.1.2 coronal planea vertical plane that is perpendicularto the median and reference planes and passes through thecrown of the headform (lateral plane).3.1.3 crowna point in the median plane wh

7、ich is equalchord lengths from the anterior and posterior intersections ofthe median and reference planes.3.1.4 drop heightthe vertical distance between the lowestpoint (impact point) of the elevated helmet and the apex of theimpact surface.3.1.5 gdimensionless ratio of the acceleration of theheadfo

8、rm during impact to the acceleration due to gravity.3.1.6 gmaxthe maximum value of g encountered duringimpact.3.1.7 median planea vertical plane that passes through theheadform from front to back and divides it into right and lefthalves (mid-sagittal plane).3.1.8 protective headgearthe assembled dev

9、ice and acces-sories as supplied by the manufacturer primarily intended toprotect the wearers head while participating in football.3.1.9 reference planea plane that is located at a specifieddistance above and parallel to the basic plane.4. Summary of Test Method4.1 Aheadgear is mounted on a headform

10、 that is oriented indifferent positions and is dropped at a specific velocity onto animpact surface.Alinear accelerometer mounted at the center ofgravity of the headform monitors the acceleration and the timehistory of impact which are recorded with appropriate instru-mentation.5. Significance and U

11、se5.1 Maximum acceleration and time duration data obtainedby the specified procedures are intended to determine the shockattenuation characteristics of a headgear.1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct

12、responsibility ofSubcommittee F08.53 on Headgear and Helmets.Current edition approved Aug. 1, 2010. Published September 2010. Originallyapproved in 1975. Last previous edition approved in 2007 as F429 01 (2007).DOI: 10.1520/F0429-10.2Performance requirements for football helmets are found in Specifi

13、cation F717.3For 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.4Available from the Society of Automotive Enginee

14、rs, 400 Commonwealth Dr.,Warrendale, PA 15096.5Available from American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been su

15、perseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information1NOTE 1These data can be used at a later date to assess the protectionafforded to the head when blows are delivered to the helmet.6. Apparatus56.1 Guide Assembly6The headform shall

16、 be attached tothe free-fall drop assembly carriage by an adjustable mountingwhich will allow impacts to be delivered to any prescribedpoint on the helmet (see Fig. 2). The carriage shall be free toslide on vertical guides. If wires are used they must be placedunder at least 845-N tension (see 12.4

17、for guide assemblyspecifications and allowable weight of drop assembly).6.2 Recording Equipment6The recording equipment shallmeet the following criteria:6.2.1 Acceleration TransducerThe acceleration trans-ducer is mounted at the center of gravity of the combined testheadform and carriage assembly wi

18、th the sensitive axis alignedto within 5 of the vertical when the helmet and headform arein the impact position. The acceleration data channel complieswith SAE Recommended Practice J211 JUN 80 (a low passfilter having a 4-pole Butterworth transfer function and acorner frequency of 1650 Hz meets this

19、 requirement). Digitalfiltering at 1650 Hz can be substituted.6.2.2 System AccuracyThe impact recording system shallbe capable of measuring shocks of up to 500-g peak accelera-tion with an accuracy of 6 5%.6.2.3 Impact RecordingThe impact shall be recorded onsingle- or dual-trace storage oscilloscop

20、e with 0.1-mV to 20-Vdeflection factor, 1 to 5-ms sweep speed-division, and 500-kHzbandwidth.6.2.4 HeadformsStandard headforms as described in 12.4will be used for helmet impact testing.6.2.5 Height Measuring RodAmetal rod accurate to 62.5mm shall be used for measuring drop heights.6.2.6 Impact Surf

21、acesThe impact surface for the instru-ment system check (see Section 10) shall be a flat, ModularElastomer Programmer (MEP),6152 mm in diameter and 25mm in thickness. The MEP shall have a durometer of 60 6 2Shore “A.” The MEP is mounted on an aluminum mountingplate with a minimum thickness of 5.59 m

22、m after grinding. TheMEP (including aluminum mounting plate) shall be firmlyaffixed to the top surface of a flat metal anvil. The base shallconsist of a rigid slab weighing at least 136 kg. For helmetimpacts, the instrument system check MEP is replaced with aMEP 13 mm in thickness, 152 mm in diamete

23、r, and adurometer of 38 6 5 Shore “A.”6.2.7 Spherical Impactor6A device made of low reso-nance material, for example, magnesium, aluminum alloy orstainless steel, that couples mechanically with the ball armconnector of the drop assembly in place of the impact testheadform. When mounted, the device p

24、resents a sphericallymachined impact face with a radius of 73 mm on its bottomsurface. All radii from the center of curvature of the impactface to its outer edge shall form angles of no less than 40 with6The sole source of supply of the apparatus known to the committee at this timeis the Research &

25、Testing Co., 1415 Park Ave., Hoboken, NJ 07030. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1which you may attend.FIG. 1 ISO Headform

26、Basic, Reference, and Median PlanesNOTE 1Rail-guided drop assemblies are also permissible.FIG. 2 Schematic of Typical Drop AssemblyF429 102the downward vertical axis. The center of curvature shall bewithin 5 mm of the vertical axis drawn through the center ofthe ball arm. The mass of the drop assemb

27、ly including theimpactor shall meet the same requirements as those specifiedfor the drop assembly incorporated with the test headforms (seesection 12.4).7. Sampling7.1 Submit at least three specimen helmets, one for testunder the various conditions as described in Section 11.8. Test Specimen8.1 At l

28、east three specimen helmets of each size to be testedas offered for sale on the open market shall be obtained fortesting. These helmets shall be tested without accessories.9. Preparation of Apparatus9.1 Turn on all electronic equipment and allow to warm upfor at least 30 min or as recommended by the

29、 manufacturer,whichever time is greater, prior to any testing.10. Instrumentation System Check10.1 The instrumentation of the entire system shall bechecked before and after each series of tests, by dropping thespherical impactor, without a helmet, onto the MEP pad at avelocity of 5.44 m/s 6 0.04 m/s

30、. This should produce a gmaxof 389 6 4 g.10.2 Record at least three impacts as described in 10.1immediately prior to and following each series of tests, andrecord on the report form.10.3 If the maximum g readings are not within the tolerancelimits prior to the test series, adjust or repair the syste

31、m asnecessary.10.4 If the mean of the three gmaxvalues following the testseries differ by more than 10 g from the mean of the g readingsof the impacts prior to the test series, discard the entire testseries.11. Conditioning11.1 Prior to testing, condition each helmet in one of thefollowing ways:11.1

32、.1 Ambient TemperatureCondition one helmet for aperiod of not less than4hatlaboratory conditions which shallbe at a temperature of 21 6 5C and a relative humidity of 506 15 %. Record the temperature to the nearest degree and therelative humidity to the nearest percent at the time of testing onthe re

33、port form for each test series.11.1.2 Low/High Temperature CycleCondition the secondhelmet by exposing it to a temperature of 20C for aminimum of 4 h, then condition it at +50C for a minimum of4 h before testing. Conditioning time in temperature transitionsis not to be included in the time at high t

34、emperature with theinterval between the two temperatures being no more than 1 h.11.1.3 Water ImmersionImmerse the third helmet in waterat a temperature of 21 6 5C for a period of not less than 4 normore than 24 h.11.1.4 Testing for Conditioned Specimens Complete alltesting on helmets within 5 min af

35、ter removal from theconditioning environment. Helmets may be returned to theconditioning environment in order to meet this requirement.Prior to the resumption of testing, specimens must remain inthe conditioning environment for a minimum of 15 min foreach 5-min period they are out of the conditionin

36、g environ-ment.12. Test Procedures12.1 Testing EnvironmentConduct all testing under therecorded conditions of room temperature and humidity. Theseconditions must be in accordance with those stated in 11.1.1.12.2 Impact LocationsImpact each helmet at not less thansix sites.All distances referred to i

37、n this section are arch-lengthdistances measured on the helmet. See Fig. 3 for a diagram ofthe impact sites.12.2.1 FrontLocated in the median plane and 81.8 mmabove the anterior intersection of the median and referenceplanes.12.2.2 Front BossA point in a plane 45 (0.78 rad) fromthe median plane as m

38、easured in a clockwise direction and 56.3mm above the reference plane.12.2.3 SideLocated at a point 30.9 mm above the inter-section of the reference plane and the coronal plane, and 90FIG. 3 Impact LocationsF429 103(1.57 rad) in a clockwise direction from the anterior intersec-tion of the median and

39、 reference planes.12.2.4 Rear BossA point in a plane 135 (2.36 rad) in aclockwise direction from the anterior intersection of themedian and reference planes, and 30.9 mm above the referenceplane.12.2.5 RearApoint 30.9 mm above the posterior intersec-tion of the median and reference planes.12.2.6 Cro

40、wnA point in the median plane that is equidis-tant from the anterior and posterior intersections of the medianand reference planes.12.3 Multiple ImpactsEach helmet tested under ambienttemperature conditions shall receive a total of 24 impacts.Impact each of the six locations on the helmet (described

41、 in12.2) three times with an impact velocity of 5.47 6 0.04 m/s.Deliver three additional impacts to each of the two locations onthe helmet at which the highest mean gmaxreadings wererecorded.12.4 Headforms and Supporting Assembly6The test head-forms to be used for helmet impact testing are SizeA, E,

42、 J, andM headforms as described in ISO/DIS 6220. The combinedweight of the instrumented headform (regardless of headformsize) and the supporting assembly (exclusive of the test helmet)shall be 5 6 0.1 kg (see Table 1).NOTE 2The weight of the supporting assembly shall not exceed 1.0kg.12.5 Reference

43、MarkingPlace the complete helmet to betested on an appropriate-sized reference headform that is firmlyplaced, with the basic and reference planes horizontal.Apply a45-N static load to the crown of the helmet, center the helmetlaterally, and adjust it in accordance with the manufacturersrecommendatio

44、ns. Maintaining the static load, draw a test lineon the outside of the helmet shell, corresponding to thereference plane of the headform. In addition to the test line,clearly mark each of the six impact points as described in 12.2.12.6 Helmet PositioningPrior to each test drop, adjust thehelmet on t

45、he headform in accordance with the manufacturersrecommendations. Secure the helmet to the headform so it doesnot shift position prior to or during the impact. Place theretention system in such a position that it does not interferewith the free fall or the impact.13. Calculation13.1 Immediately after

46、 each impact, take the followingmeasurements of the acceleration time-history trace:13.1.1 Maximum AccelerationFind the maximum ampli-tude of acceleration by measuring the perpendicular distance tothe trace base line from the midpoint of the trace at maximumexcursion and multiplying by the sensitivi

47、ty factor. (Sensitivityfactor = g per division deflection of the trace.)13.1.2 Duration of ImpulseDetermine the duration of thepulse by measuring the total width of the trace along the 50-gline in milliseconds.13.1.3 OscillogramsTake photographs of the oscilloscopeon the third impact at each impact

48、site conducted underambient conditions. Affix these oscillograms to the final reportof testing.14. Report14.1 Each laboratory report shall be accompanied by theoscillograms prescribed in 13.1.3 and shall contain the follow-ing minimum information:14.1.1 Helmet IdentificationComplete identification o

49、f thehelmet including but not limited to the following:14.1.1.1 Manufacturers identification,14.1.1.2 Size,14.1.1.3 Manufacturers lot number,14.1.1.4 Weight, and14.1.1.5 External circumference at reference plane.14.1.2 Conditions of TestThe report shall include detailedinformation of the conditions under which the tests wereconducted as follows:14.1.2.1 Date of test,14.1.2.2 Temperature,14.1.2.3 Humidity, and14.1.2.4 Record of the instrument calibration.14.1.3 Test ResultsDetailed results of the impact testi