1、Designation: F2650 07F2650 13 An American National StandardStandard Terminology Relating toImpact Testing of Sports Surfaces and Equipment1This standard is issued under the fixed designation F2650; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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 terminology covers terms related to impact test methods and impact attenuation specifi
3、cations of sports equipment andsurfaces.1.2 This terminology is appropriate for use in the development of standards that describe gravity-driven impact test methodsor specify impact attenuation performance criteria and which fall under the jurisdiction of ASTM Committee F08 on SportsEquipment and Fa
4、cilities.1.3 This terminology defines common terms that are applicable to many sports-related impact tests including those used in thecontext of sports surfaces, athletic footwear, protective equipment and padding. The use of a common terminology will promotegreater consistency among standards and r
5、educe the risk of misinterpretation.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.2. Terminology2.1 Definitions:acceleration, nrate of change of velocity with time.DISCUSSIONAcceleration is a vector quantity, having bot
6、h magnitude and direction. Acceleration magnitude is expressed in units of m/s2 (ft/s2) and direction isdefined relative to a Cartesian coordinate system or other spatial reference frame.assisted impact test, nan impact test in which the missile is accelerated by means other than gravity alone, for
7、example, by anactuator.drop height (h),nheight from which a missile is dropped during a gravity-driven impact test, measured as the vertical distancebetween the lowest point of the elevated missile and its first point of contact with the impacted surface or anvil.theoretical drop height, ndrop heigh
8、t (h) that, under standard conditions, would result in an impact velocity equal to a missilesmeasured impact velocity (V0).DISCUSSIONThe “standard conditions” assume standard gravity and that friction and air resistance do not affect the fall of the missile. In a free-fall impact test theactual drop
9、 height will approximate the theoretical drop height. In a guided impact test, the theoretical drop height will be less than the actual dropheight, due to the effects of friction in the guidance mechanism.g, n(pronounced “gee”) a unit of acceleration equal to standard gravity. Missile accelerations
10、expressed in g units are the ratioof the missile acceleration to standard gravity and are hence dimensionless.DISCUSSION1 This terminology is under the jurisdiction of ASTM Committee F08 on Sports Equipment Equipment, Playing Surfaces, and Facilities and is the direct responsibilityof Subcommittee F
11、08.80 on Common Terminology, Methods and Laboratory Practices.Current edition approved Aug. 1, 2007June 1, 2013. Published September 2007July 2013. Originally approved in 2007. Last previous edition approved in 2007 asF2650 07. DOI: 10.1520/F2650-07.10.1520/F2650-13.This document is not an ASTM stan
12、dard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all case
13、s only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1The symbol g is properly written in lowercase and italic, to distinguish it from
14、the symbol G (uppercase, used to indicate the gravitational constant)and g (not italicized) which is an abbreviation of the gram unit.g-max, nmaximum acceleration magnitude recorded during a single impact, expressed in g units.average g-max, narithmetic average of a specified set of g-max values.gra
15、vity-driven impact test, nan impact test in which the missile is accelerated by gravity alone, during a period of free-fall.head injury criterion (HIC), nweighted impulse criterion calculated from a head impact acceleration-time profile and used toquantify head impact severity. The HIC calculation r
16、esults in a severity index that is weighted by both impact accelerationmagnitude and by the time for which high magnitude accelerations persist.DISCUSSIONHIC scores can only be directly referenced to the head injury risk data on which the criterion is based if the impact acceleration-time profile is
17、 recordedusing a human head or a biofidelic headform. HIC scores determined using rigid missiles and headforms tend to over estimate head injury risk.headform, nmissile with mass and geometry approximating those of the human head.biofidelic headform, nheadform with elastic properties approximating t
18、hose of the human head.rigid headform, nheadform fabricated from very stiff materials (for example, steel or aluminum) such that its deformationduring an impact is negligible.impact attenuation, nreduction of loads produced in the course of an impact by means of a cushioning system or device, relati
19、veto a load criterion or to the loads produced by a reference system.DISCUSSIONLoad measures used to quantify impact magnitude include force, acceleration, stress and pressure and their time derivatives.impact energy, nthe kinetic energy of a missile at the instant of initial contact with the target
20、.DISCUSSIONIn a gravity-driven test, impact energy is equal to the potential energy of the missile at the theoretical drop height. See also total energy input.missile, nin a gravity-driven impact test, the object mass that falls under gravity to produce an impact.reference plane, nplane parallel to
21、the surface or normal to the path of the missile and from which missile displacement ismeasured.rigid surface, na reference surface (for example, a concrete surface covered by a steel plate) used as the basis for measuringforce reduction.shock absorption,nsee shock attenuation.shock attenuation, nim
22、pact attenuation where the measure of load is the peak magnitude of acceleration produced by an impact.(See impact attenuation.)standard gravity, nnominal value of the acceleration due to gravity at sea level having an international standard value of exactly9.80665 m/s2 (approximately 32.174 ft/s2).
23、time to g-max, nelapsed time from the onset of impact until the time at which g-max occurs.DISCUSSIONDepending on the application, the “onset of impact” may be defined as the time at which the missile intersects a zero reference plane or as the timeat which a measured deceleration of the missile exc
24、eeds a small threshold value.total energy input, nthe total energy transferred to the target, up to the point of maximum target displacement, the sum of theimpact energy and the additional potential energy transferred during target displacement.F2650 1323. Keywords3.1 athletic equipment; athletic fi
25、eld; impact; impact testing; playground equipment; playground surfaces; sports; sportsequipment; sports field; sports surfacesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are e
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28、y attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United Sta
29、tes. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F2650 133
