1、Designation: F2117 10 (Reapproved 2017) An American National StandardStandard Test Method forVertical Rebound Characteristics of Sports Surface/BallSystems; Acoustical Measurement1This standard is issued under the fixed designation F2117; the number immediately following the designation indicates th
2、e 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 covers the quantitative measureme
3、ntand normalization of the vertical rebound produced duringimpacts between athletic balls and athletic surfaces.1.2 Measurements may be conducted on nonathletic sur-faces to test the performance properties of the ball.1.3 Measurements may be conducted using nonathletic ballsto test the performance p
4、roperties of the surface.1.4 The methods described are applicable in both laboratoryand field settings.1.5 The values stated in metric units are to be regarded asthe standard. The inch-pound units given in parentheses are forreference only.1.6 This standard does not purport to address all of thesafe
5、ty concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internati
6、onally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 DIN (Deutsches Institut f
7、ur Normung):218032 Part II, 1991 Section 5.82.2 British Standards:37044, 1990, Section 2.12.3 EN (European Committee for Standardization):4EN 12235 Surfaces for sports areas - Determination ofvertical ball behaviour3. Terminology3.1 Definitions:3.1.1 area elastic surface, nsurfaces where the energy
8、atimpact is dispersed throughout an area significantly larger thanthe impact point (for example, sprung wooden basketballfloors, poured urethane floors over sprung subfloor). Areaelastic surfaces tend to produce a noticeable vibration whenimpacted.3.1.1.1 subfloor, nany structural members found betw
9、eenthe playing surface and the underlying concrete base. Subfloorsystems are typically found in sprung indoor playing surfacesand can include but are not limited to: layers consisting ofsheets of plywood, layers consisting of strips of plywood, andsolid-wood members.3.1.2 athletic surface, nan athle
10、tic surface appropriate forthe sport(s) of interest should be selected for testing. Thesurface may be selected from previously installed surfaces andtested in its complete form, or smaller samples may be testedunder laboratory settings.3.1.3 coeffcient of restitution (CR), nthe ratio of reboundheigh
11、t to release height. This parameter is useful for nonin-flated balls that are found to be damaged by impacts with aconcrete reference surface. Construction differences and sen-sitivity to inflation pressure make this parameter inappropriatefor comparing different playing surfaces based on resultsobt
12、ained using inflated sporting balls.3.1.4 point elastic surface, nsurface where the energy atimpact is dispersed throughout an area that negligibly exceedsthe impact point (for example, natural turf, artificial turf,poured urethane surfaces). Point elastic surfaces do not pro-duce noticeable vibrati
13、ons when impacted.3.1.5 reference surface, nany section of a concrete slabwith a smooth uniform, uncracked surface with a minimumhorizontal dimension of 30 cm (12 in.) that produces a reboundwith minimal horizontal movement.3.1.6 resting time constant (Kr), na time constant thatcorrects for the dura
14、tion that the ball is in contact with thesurface.3.1.7 sporting ball, na sporting ball appropriate for thesport(s) of interest should be selected for testing. The test ball1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is th
15、e direct responsibility ofSubcommittee F08.52 on Miscellaneous Playing Surfaces.Current edition approved April 1, 2017. Published April 2017. Originallyapproved in 2001. Last previous edition approved in 2010 as F2117 10. DOI:10.1520/F2117-10R17.2Available from DIN, Burggrafenstrasse 6, D-10787 Berl
16、in, Germany.3Available from BSI, 389 Chiswick High Road, London W4 4AL, UK.4Available from ANSI, 1819 L Street, Washington, DC 20036, USA.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in acco
17、rdance with internationally recognized principles on standardization 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.1should be inspected to verify t
18、hat it is spherical and devoid ofbulges. Bulges indicate structural damage exists within theball, that could affect the testing results. In the case of inflatedsporting balls, the pressure should conform to manufacturersguidelines.3.1.8 vertical rebound height, nthe highest heightachieved by sportin
19、g ball during its first rebound after contact-ing the surface, as measured from the bottom of the ball to thetop of the surface.3.1.9 vertical rebound ratio (VRR), nthe ratio of therebound on the test surface to the rebound on the referencesurface, expressed as a percentage. This parameter may not b
20、eappropriate for all sporting balls, as some may experiencedamage when impacting the reference surface. When referencesurface rebound measurement is found to be unrepeatable, thecoefficient of restitution should be used instead.4. Summary of Test Method4.1 This test method provides a means for evalu
21、ating therebound height produced by a test ball on a test surface. Theprocedure can be used to evaluate vertical ball reboundperformance on a reference athletic surface, evaluate surfacevertical rebound performance using a reference athletic ball, orto evaluate the effects of ball-surface interactio
22、ns. A ball isreleased from a known height and allowed to impact thereference surface. The release should not impart any horizontalmotion. An acoustical measurement system measures therebound height obtained on the test surface. The ball is thenreleased from the same height and allowed to impact the
23、testsurface, where again, the rebound height is measured. Thevertical rebound ratio, presented as a percentage, is obtainedfrom the ratio of the vertical rebound height on the sportingsurface to the vertical rebound height on the reference surface.5. Significance and Use5.1 The ball-surface interact
24、ion is just one of the importantproperties of a sports surface. It may be an indicator of theplayability or suitability of the surface.5.2 Manufacturers of sporting balls may use this method toevaluate the effects of design changes on the rebound heightproduced.5.3 Manufacturers of sports surfaces m
25、ay use this method toevaluate the effects of design changes in the sports surfacesystem on the rebound height produced.5.4 The tendency of modern facilities to support multiplesports on a single surface may require that test surfaces betested for several types of sporting balls. Examples include, bu
26、tare not limited to: basketball, soccer, tennis, and baseball.5.5 The measurement of rebound height may be affected ifthe temperature of the ball has not reached equilibrium with theenvironment.6. Apparatus6.1 Ball-Release Apparatus, capable of releasing the sport-ing ball from a consistent height,
27、without imparting significantspin or horizontal motion to the sporting ball. The ball releaseapparatus is typically an adjustable-height tripod. The releasemechanism may be mechanical, electromagnetic, vacuum, ormanual.6.2 Sound Recording and Analysis SystemA system withthe minimum requirements as f
28、ollow: acoustic sampling fre-quency 11 000 Hz, 8-bit resolution, on a single acousticchannel. The system must be capable of determining the timeof the first (tl) and second (t2) impacts using the peak acousticsignal generated to determine tland t2through either the use ofhardware or software.6.2.1 E
29、xamplePersonal computer, sound-card, and micro-phone have been found to produce adequate results.7. Testing Conditions7.1 The following general testing conditions should berecorded and included in the test report for informationpurposes only:7.1.1 All Surfaces:7.1.1.1 Record temperature (to the near
30、est 1C) and relativehumidity (to the nearest 1 %) at an elevation of 30 6 5cm(126 2 in.) above the playing surface. Measurements may beobtained using hand-held commercially available temperatureand relative humidity sensors.7.1.1.2 The vertical ball rebound should be tested using a1.800 6 0.005-m (7
31、1 6 0.2-in.) drop height, as measured fromthe bottom of the ball to the top of the test surface. Additionaldrop heights may be tested and should be agreed on by thepurchaser and the seller.7.1.2 Wood Playing SurfacesThe wood moisture content(%) should be included. Measurements may be obtained usingh
32、and-held commercially available wood moisture sensors.7.1.3 Outdoor Playing SurfaceThe general moisture levelof the surface should be included. In general, the surfaceshould be characterized as dry, damp, or wet.7.1.4 Laboratory Sample Sizes:7.1.4.1 Area elastic surfaces should be evaluated using am
33、inimum sample size of 2.0 by 2.0 m (6.5 by 6.5 ft).7.1.4.2 Point elastic surfaces should be evaluated using aminimum sample size of 1.0 by 1.0 m (3.3 by 3.3 ft).8. Procedure8.1 When the ball and test surface are introduced to a newenvironment, each should be allowed to acclimate. The ballshould be a
34、llowed to acclimate to the surroundings for 1 h, andthe surface should be allowed at least4htoacclimate to theenvironment.8.2 Measure and record ambient temperature to the nearest1C and the relative humidity to the nearest 1 % at a height of30 cm (12 in.) over the reference surface.8.3 Measure and r
35、ecord ambient temperature to the nearest1C and the relative humidity to the nearest 1 % at a height of30 cm (12 in.) over the athletic surface.8.4 Locate and document all points to be tested. Thisincludes points on the reference surface and on the athleticsurface.8.4.1 When testing under field condi
36、tions, include a diagramof the playing surface and its surroundings and dimensions thatF2117 10 (2017)2allow the test points to be relocated. Effort should be made tolocate and test rebound properties of the playing surface onareas representative of the surface conditions present andconstruction met
37、hods used in the playing surface. Tests shouldalso be conducted on areas considered heavy-use and non-useareas. Examples include but are not limited to the following:8.4.1.1 Natural TurfDensely covered areas and skinnedareas.8.4.1.2 Artificial TurfSeams in the turf layer, seams in thepadding layer (
38、if present).8.4.1.3 Point Elastic SurfacesSeams in the playing sur-face and seams in the padding layer (if present).8.4.1.4 Area Elastic SurfacesJoints in the playing surface,joints in the subfloor layer (if present), joints in the sleeperlayer (if present), between sleepers (if present), seams inpa
39、dding layer (if present), individual pads (if present).8.4.2 When testing under laboratory conditions, include adescription of the overall system construction and a descriptionof construction details present at all test points.8.5 Set the drop height to the nominal desired height. Theactual drop hei
40、ght should be measured and recorded to thenearest 0.005 m (0.2 in.). The surface/ball system should beevaluated using a nominal drop height of 1.800 6 0.005 m (716 0.2 in.) and any additional drop heights considered useful.8.6 Perform ball inspection; verify that construction is stillsound. When app
41、ropriate, verify that the inflation pressure iswithin manufacturers specifications and record actual pres-sure.8.7 Evaluate the rebound height from the desired point onthe reference surface by recording five vertical rebound heightsproduced from the specified testing height on the referencesurface t
42、o the nearest 0.005 m (0.2 in.), calculate the timebetween impacts (tref-1) and the rebound height (href-k) for allfive drops and the average rebound height for the referencesurface (href-1). Sporting balls without inflation valves (such asgolf balls, racquetballs, and so forth) are released from th
43、e dropheight with a random orientation. Sporting balls with inflationvalves (soccer balls, basketballs, and so forth) are released withthe inflation valve pointing away from the impact surface.8.8 Move the release apparatus to the athletic surface, andverify that the release height has not changed.8
44、.9 A minimum of three points should be evaluated usingthe methods and accuracies described in 8.7 to characterize anyplaying surface. Evaluate the rebound height from the desiredpoint on the test surface by recording five vertical reboundheights produced from the specified testing height. Calculatet
45、he time between impacts (ti,j), and the rebound height (hi,j)from each point (i) and drop (j). For each point, calculate theaverage vertical rebound height from all 5 drops for each testpoint.8.10 When the testing is conducted to evaluate the proper-ties of balls on a given surface, each ball will b
46、e dropped 5times.8.11 Verify that the rebound height has not changed duringtesting by retesting the reference point every 30 min (maxi-mum allowable time duration) and at the conclusion of everytested surface. Record five rebound measurements followingthe methods in 8.7 and calculate the average tim
47、e betweenrebounds (tref-2) and the average rebound height for thereference surface (href-2).8.12 Record the inflation pressure of the ball, whenappropriate, at the conclusion of evaluating the playing surface.The inflation pressure is for information purposes only and canbe obtained using a low-pres
48、sure gage of the type available atautomotive stores.9. Calculations9.1 Rebound height is approximated using the time duration(t) between the first (tl) and second (t2) impacts of the ballwith the surface, with t, tland t2measured to the nearest0.001 s (tl, and t2are obtained from the moment of maxim
49、umsound intensity generated during the impact).ts! 5 t22 t1(1)9.2 The average time between the first and second impactsexcluding the maximum and minimum time differences shouldbe computed to the nearest 0.001 s for each point i tested onthe playing surface (ti) and for each test j on the referencesurface (trefj).t$i%5t11t21t31t41t55(2)9.3 The average time between the first and second impactsof the ball with the playing surface is then converted to verticalrebound height for each point i and drop j on the playingsurface (hi) and
