1、Designation: F1976 13 An American National StandardStandard Test Method forImpact Attenuation of Athletic Shoe Cushioning Systemsand Materials1This standard is issued under the fixed designation F1976; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 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 describes the use of a gravity-drivenimpact test to measure certain im
3、pact attenuation characteris-tics of cushioning systems and cushioning materials employedin the soles of athletic shoes.1.2 This test method uses an 8.5 kg mass dropped from aheight of 30-70 mm to generate force-time profiles that arecomparable to those observed during heel and forefoot impactsdurin
4、g walking, running and jump landings.1.3 This test method is intended for use on the heel and orforefoot regions of whole, intact athletic shoe cushioningsystems.An athletic shoe cushioning system is defined as all ofthe layers of material between the wearers foot and the groundsurface that are norm
5、ally considered a part of the shoe. Thismay include any of the following components: outsole or otherabrasion resistant outer layer, a midsole of compliant cushion-ing materials or structures forming an intermediate layer, aninsole, insole board, or other material layers overlying themidsole, parts
6、of the upper and heel counter reinforcementwhich extend beneath the foot, and an insock, sockliner orother cushioning layers, either fixed or removable, inside theshoe.1.4 This test method may also be employed in to measurethe impact attenuation of cushioning system components andcushioning material
7、 specimens.1.5 This test method is not intended for use as a test of shoesclassified by the manufacturer as childrens shoes.1.6 The type, size or dimensions and thickness of thespecimen, the total energy input and prior conditioning shallqualify test results obtained by this test method.1.6.1 The ra
8、nge of tests results is limited by the calibratedrange of the test devices force transducer. Combinations ofthin specimens, high specimen stiffness and high total energyinput may produce forces that exceed the transducers capacityand are hence not measurable. In practice, the specified forcetransduc
9、er range (10 kN) accommodates more than 99 % oftypical shoe soles and cushioning material specimens that are7 mm or more in thickness at a total energy input of 5 Joules.1.6.2 The nominal value of the total energy input applied bythis test method is 5 J for shoes, such as running shoes, whichare sub
10、ject to moderate impacts during normal use. Totalenergy inputs of 7.0 J and 3.0 J may be used for shoes (e.gbasketball shoes) which are subject to higher impact loadsduring normal use. Other values of total energy input may beused, if they are stated in the report.1.6.3 Results from tests performed
11、with different totalenergy inputs or with different masses are not directly compa-rable.1.6.4 Specimen thickness has a significant effect on impactattenuation outcomes. Consequently, results from tests ofmaterial specimens of different thicknesses cannot be directlycompared.1.6.5 The impact attenuat
12、ion of cushioning materials maychange over time and with use (e.g. wear or durability testing)or prior conditioning (e.g. from previous tests). Consequently,test results obtained using this test method shall be qualified bythe age and prior conditioning of the samples.1.7 The values stated in SI uni
13、ts are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 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 establish appro-priate safety and health prac
14、tices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF1614 Test Method for Shock Attenuating Properties of1This test method is under the
15、 jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility ofSubcommittee F08.54 on Athletic Footwear.Current edition approved May 1, 2013. Published August 2013. Originallyapproved in 1999. Last previous edition approved in 2006 as F197
16、6 06. DOI:10.1520/F1976-13.2For 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.Copyright ASTM International, 100
17、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Materials Systems for Athletic FootwearF2650 Terminology Relating to Impact Testing of SportsSurfaces and Equipment3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminolog
18、y F2650.3.2 Definitions of Terms Specific to This Standard:3.2.1 low impactimpact during which the peak groundreaction force is less than 1.5 body weights and the peak axialdeceleration of the lower leg is less than 4 g.3.2.2 moderate impactimpact during which the peakground reaction force is greate
19、r than 1.5 body weights and lessthan 3 body weights and the peak axial deceleration of thelower leg is greater than 4 g but less than 8 g.3.2.3 high impactimpact during which the peak groundreaction force exceeds 3 body weights or the peak axialdeceleration of the lower leg exceeds 8 g.3.2.4 shoe up
20、pervamp, tongue, heel counters, throat,collar, and other parts of the shoe that do not form part of thecushioning system.3.2.5 tupleading surface of moving portion of test ma-chine in contact with specimen during the impact cycle.4. Summary of Test Method4.1 The test apparatus consists of a rigid fo
21、undation with asupport structure that guides the fall of an 8.5 kg, gravitydriven missile. The apparatus includes a mechanism for posi-tioning the missile at a predetermined drop height, thencyclically releasing it at a nominal rate of 30 cycles per minute.4.2 A test specimen is supported by the rig
22、id foundation.The drop height is adjusted to produce a specified total energyinput, typically 5 Joules. Specimens are subjected to a series of30 impacts with a nominal interval of 2.0 s. The first 25 dropsused to condition the specimen and the last five drops used formeasurements. Force and displace
23、ment time histories aremeasured with appropriate transducers and recorded. Theprimary outcomes of the test are the peak acceleration duringthe impact (g-max), time to peak acceleration (t-max), peakcompressive displacement (x-max) of the specimen and energyreturn/loss due to hysteresis.5. Significan
24、ce and Use5.1 This test method is used by athletic footwear manufac-turers and others, both as a tool for development of athleticshoe cushioning systems and as a test of the general cushioningcharacteristics of athletic footwear products, materials andcomponents. Adherence to the requirements and re
25、commenda-tions of this test method will provide repeatable results that canbe compared among laboratories.5.2 Data obtained by these procedures are indicative of theimpact attenuation of athletic shoe cushioning systems underthe specific conditions employed.5.3 This test method is designed to provid
26、e data on the forceversus displacement response of athletic footwear cushioningsystems under essentially uniaxial impact loads at rates that aresimilar to those of heel and forefoot impacts during differentathletic activities.5.4 The peak or maximum values of force, acceleration,displacement, and st
27、rain are dependent on the total impactenergy applied to the specimen. These values are normalized toprovide comparative results for a reference value of totalenergy input.5.5 Impact attenuation outcomes are strongly dependent oninitial conditions (impact mass, impact velocity, contact area,etc.) and
28、 on specimen size and the specimens prior history ofcompressive loading. Therefore results should be comparedonly for specimens of the same nominal size and priorconditioning.NOTE 1Impact test outcomes have been found to correlate within-vivo loads (peak ground reaction force, peak plantar pressure,
29、 lowerextremity acceleration) experienced by runners. Relationships betweentest outcomes and subjective perceptions of cushioning have also beenfound. However, there is no direct evidence of a correlation betweenscores on this test method and the probability of injury among users of aparticular athl
30、etic footwear product.6. Test Apparatus6.1 The test device (Fig. 1) shall consist of two primaryassemblies, the first providing a fixed anvil and structures forthe support, alignment and guidance of a second, gravity-driven missile assembly (Fig. 1).6.2 Fixed Anvil Assembly, (Fig. 1(A) consisting of
31、 aneffectively rigid anvil having a minimum mass of 170 kg andproviding a flat, rigid surface for specimen support. Thespecimen support surface shall be planar, normal to the verticaldirection of missile travel, centered under the tup of thegravity-driven assembly and of sufficient area to support t
32、heentire lower surface of the specimen.6.2.1 Support and GuidanceThe fixed assembly shallprovide linear bearings or other means guidance for a gravity-driven missile such that the motion of the missile is vertical andnormal to the plane of the specimen support surface.6.2.2 Lift and Drop MechanismA
33、means of lifting themissile above the upper surface of the specimen, repeatablypositioning it with an accuracy of 60.5 mm releasing it toinitiate a gravity-driven drop.6.2.2.1 The testing machine shall be capable of initiating theimpact cycle (that is, loading and unloading as one cycle) at arate of
34、 one every 2 6 1s.NOTE 2The adjustable range of the lift and drop mechanism mustaccommodate the thickness of the specimen (typically 10 to 50 mm) plusthe drop height required to produce the specified total input energy(typically 30 to 70 mm).6.2.3 FrictionThe missile assembly shall move freely,with
35、minimum friction between the missile and the bearings orother guidance structure. Any friction shall be such that themeasured free-fall velocity,V0, from a drop height h, shall bewithin 62 % of the theoretical value given by V = (2gh)where g is the acceleration due to gravity.6.3 Missile AssemblyA g
36、ravity-driven missile assembly(Fig. 1(C) consisting of a main missile body, a missileF1976 132extension and a tup and incorporating a force transducer (see6.4). The total mass of the assembly shall be 8.5 6 0.1 kg.6.3.1 Missile ExtensionThe missile extension shall beconstructed in a manner that allo
37、ws the tup to contact andpenetrate the specimen without any other portion of the missileassembly making contact with the surface of the specimen orother specimen components (for example, sidewalls and uppercomponents).6.3.2 TupThe tup shall be cylindrical with a circular face45.0 6 0.1 mm in diamete
38、r and an edge radius of 1.0 6 0.2 mm(Fig. 2). The total mass suspended from the force transducer(that is, the mass of the tup and its means of connection shallnot exceed 0.20 kg).NOTE 3Tups of appropriate mass and stiffness can be constructedfrom aluminum alloy 6061.FIG. 1 Schematic Diagram of the T
39、est DeviceF1976 1336.4 Force TransducerA force measuring device mountedrigidly between the missile extension and the tup with itssensitive axis aligned (60.5 mm) with a vertical line passingthrough the center of the tups circular face.6.4.1 The force transducer shall have a calibrated measure-ment r
40、ange in compression, of at least 0 to 10 kN range, adischarge time constant exceeding 2 s and nonlinearity notexceeding 1 % full scale.6.4.2 Accelerometers are not acceptable substitutes forforce transducers in this application.6.5 Displacement TransducerA means of measuring theposition and displace
41、ment of the missile assembly relative tothe fixed anvil assembly. The transducer may be mechanical,having a fixed end attached to the support structure and amoving end attached to the missile assembly. Optical and othernon-contact transducers are also acceptable provided theymeet the requirements of
42、 6.5.1.6.5.1 The displacement transducer shall have a calibratedrange equal to or greater than the range of motion of the missileassembly, typically 100 to 150 mm (see Note 2) an accuracy of60.1 mm, a flat (61 %) frequency response from 0 to 1000 Hzand nonlinearity not exceeding 1 % full scale. Mech
43、anicaltransducers attached to the missile should also be resistant toimpact shock magnitudes of at least 100 g.6.6 CalibrationForce and displacement transducers shallbe calibrated in accordance with the manufacturers recom-mendations and at the recommended interval.6.7 Data RecordingAn analog to dig
44、ital converter or othermeans of recording force transducer output with a resolution of61 N and displacement output with a resolution of 60.1 mm.6.7.1 Sample RateThe data recorder shall have a mini-mum sample rate of 5000 samples/s.6.7.2 Anti-aliasing FilterInput signals shall be filtered,prior to di
45、gitization, using analog filters with -3dB cut-offfrequencies equal to 50 6 10 % of the actual sample rateemployed (that is, 2500 6 100 Hz for a sample rate of 5000samples/s).6.7.3 Digital FilterDigitized data shall be digitally filteredusing a fourth order low pass IIR filter (for example, a digita
46、lButterworth filter) with a -3dB cut-off frequency of 500 Hz.6.8 DisplayA means of displaying force and displacementdata as a function of a common time scale or force as a functionof displacement, or both (see Fig. 3).7. Test Specimen7.1 Preparation of Test SpecimensThe cushioning testspecimen shall
47、 be isolated from the shoe by cutting away theupper. The lower portion of the upper (that which extends 10 65 mm (0.4 6 0.2 in.) above the top surface of the cushioningsystem) shall not be removed, providing it does not interferewith the falling mass.NOTE 4The retention of a rim of upper materials a
48、round the edge ofthe test specimen prevents disturbance of the cushioning materials duringremoval of the upper, preserves the attachments between the sole and theupper (which can influence shock attenuation), and serves as a retainer forany loosely attached components of the cushioning system that n
49、ormallyreside inside the shoe (an insock, for example).7.2 GeometryIn order for this test method to beapplicable, the region of the cushioning system to be testedshall have an approximately flat surface, approximately circu-lar in shape, with a minimum diameter of 65 6 2 mm (2.6 60.1 in.). The center of this presenting surface shall coincidewith the center of the tup of the test apparatus, such that oninitial contact between the tup and the test specimen there is aminimum of 5 6 1-mm (0.2 6 0.05-in.) clearance between theedge of the tup and the
