1、Designation:F221911F221913 An American National Standard Standard Test Methods for Measuring High-Speed Bat Performance 1 This standard is issued under the xed designation F2219; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the
2、 year of last revision.Anumber in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 Amethod for determining bat performance by measuring the bat-ball coefficient of restitution (BBCOR), derivin
3、g the ball exitspeedratio(BESR),andcalculatingabatted-ballspeed(BBS).Itisapplicabletobaseballandsoftballbatsofanyconstruction or material. The test methods provide quantitative measures of bat dynamic performance that may be used for comparison purposes. 1.2 The BBCOR, BESR, and BBS are each calcula
4、ted from measurements taken in the laboratory on test equipment meeting the requirements dened in this standard. 1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only a
5、nd are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limit
6、ations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 F1887Test Method for Measuring the Coefficient of Restitution (COR) of Baseballs and Softballs F1888Test Method for Compression-Displacement of Baseballs and Softballs F2398Test Method for Measuring Moment of Inertia and Center of Pe
7、rcussion of a Baseball or Softball Bat F2845Test Method for Measuring the Dynamic Stiffness (DS) and Cylindrical Coefficient of Restitution (CCOR) of Baseballs and Softballs 3. Terminology 3.1 Denitions of Terms Specic to This Standard: 3.1.1 balance point (BP), ndistance to the center of mass from
8、the knob end of the bat. 3.1.2 ball exit speed ratio (BESR), nratio of ball exit speed to the ball inbound speed plus 1 2 . 3.1.3 bat-ball coeffcient of restitution (BBCOR), nCOR of a specic ball colliding with a bat. 3.1.4 batted ball speed (BBS), nthe speed that a ball would be hit off a bat in pl
9、ay based on given pitch and bat speeds. 3.1.5 coeffcientofrestitution(COR),nmeasureofimpactefficiencycalculatedastherelativespeedoftheobjectsafterimpact divided by the relative speed of the objects before impact. 3.1.6 cylindricalcoeffcientofrestitution(CCOR),ntheratioofthereboundtoincomingspeedofab
10、allimpactingasolidrigid cylinder. 3.1.7 dynamic stiffness (DS), na normalized measure of the ball impact force having units of stiffness (lb/in. or kN/m). It is obtained by dividing the square of the peak force between the ball and impact surface by the ball mass and the square of the incoming ball
11、speed. 1 These test methods are under the jurisdiction of ASTM Committee F08 on Sports Equipment, Playing Surfaces, and Facilities and are the direct responsibility of Subcommittee F08.26 on Baseball and Softball Equipment. Current edition approved Nov. 1, 2011June 1, 2013. Published December 2011Ju
12、ly 2013. Originally approved in 2002. Last previous edition approved in 20102011 as F221910.F221911. DOI: 10.1520/F2219-11.10.1520/F2219-13. 2 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.ForAnnualBookofASTMStandards volume information, re
13、fer to the standards Document Summary page on the ASTM website. This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because it may not be technically possible to adequately depict all c
14、hanges accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version of 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 19428-295
15、9. United States 13.1.8 moment of inertia (MOI), nmeasure of mass distribution relative to an axis of rotation. It is the product of the mass multiplied by the square of the distance to the mass, summed over the entire bat. 3.1.9 test sponsor, ngroup, association or individual specifying test requir
16、ements including ball specications, performance measure, and test speed. 4. Signicance and Use 4.1 These test methods offer a laboratory measure of means to quantitatively compare the performance of baseball and softball bats. 4.2 Use of these test methods can provide quantitative metrics of bat per
17、formance. 5. Apparatus and Equipment 5.1 Test BallsBaseballs or softballs as determined by the test sponsor. 5.1.1 Ball specication values are to be recorded and traced to individual balls. 5.2 Bat-Ball Test Apparatus: 5.2.1 Ball CannonA device capable of shooting a ball at speeds up to 220 ft/s (67
18、.1 m/s, 150 mph). Balls shall be oriented to impact the strike surface between the stitches. Typical pitching machines cannot yield the aiming accuracy required by these test methods. Cannon exhaust air must not cause motion of the bat in the absence of an impact. 5.2.2 Ball Speed GateLight screens
19、capable of measuring a ball traveling at speeds up to 220 ft/s (67.1 m/s, 150 mph), with anaccuracyofatleast60.7ft/s(60.2m/s).Thedeviceshallmeasureacrossalengthofnolessthanhalftheballdiametertoavoid centering error. The rst sensor shall be located no more than 12.0 in. (304.8 mm) from the bat surfac
20、e. The second sensor shall belocated660.03in.(15260.8mm)aftertherstsensor(seeFig.1).Theballspeedgatemustmeasuretheballreboundspeed. 5.2.3 BallAngleMeasurementUseoneofthefollowingdevicestomeasureMeasureandrecordtheballverticalandhorizontal rebound angles within 1.1, using at least one of the followin
21、g or equivalent devices. 5.2.3.1 Angled Light GatesAlight trap device capable of measuring the ball rebound angle after impact with a bat (see Fig. 2). The device shall measure across a length of no less than half the ball diameter to avoid centering error. The vertical rebound FIG. 1Bat Testing Mac
22、hine F221913 2angle gate shall be mounted at approximately 45 relative to the inbound ball path. The horizontal rebound angle gate shall be mounted at approximately 25 relative to the inbound ball path (to provide room for the speed gates). (Appendix X1.) 5.2.3.2 High-Speed High Speed CameraA high-s
23、peed high speed video camera capable of recording the ball rebound path. If a mirror is placed at 45 atop the light box, one video camera can observe both the horizontal and vertical planes. (Appendix X2.) 5.2.4 Bat Pivot SupportA turntable, rotating in the horizontal plane, with clamps to support a
24、nd align the bat in the path of the ball.The rotating clamp and shaft assembly shall not weigh more than 6 lb (2.7 kg) and shall spin freely via ball bearings (see Fig. 1). The MOI of the clamp turntable assembly shall be determined, recorded, and used in the performance calculations. The MOI for th
25、e clamp turntable assembly shall not exceed 300 oz-in. 2 (5498 kg-mm 2 ). 5.2.5 Bat Speed SensorDevice to measure bat rotational speed for at least 100 after impact. Device shall read speeds up to 3000/s with an accuracy of at least 1/s (found to be achievable using an optical encoder). Bat speed is
26、 taken from the slope of the linear least-squares t to the bat rotation versus time data between 5 and 95 after impact. 6. Calibration and Standardization 6.1 Ball Speed GateThe distance between the sensors of the speed gates should be measured and recorded. The timers used for speed measurements sh
27、ould be calibrated on at least a yearly basis. 6.2 Reference Standards and BlanksA standard bat and ball shall be used for monthly reference purposes to verify proper machine operation. 6.3 Location Tolerance: 6.3.1 BatCoat the impact area of the bat with a removable material (dry erase marker or po
28、wder). 6.3.2 BallImpact the bat with a solid coverless ball such as a pitching machine baseball or softball core. 6.3.3 LocationForeachimpact,usetheaverageoftheballcontactedgesonthebatastheimpactlocation.Theimpactlocation is the average location from six balls. 6.3.4 ToleranceThestandarddeviationoft
29、hesiximpactsmustbelessthan0.125in.Thedifferencebetweenthetargetlocation and the average location from the six impacts must be less than 0.125 in. 7. Conditioning 7.1 Ball and Bat Conditioning and Test Room Conditions: FIG. 2Diagram Showing Light Gate Arrangement to Measure the Ball Speed, the Horizo
30、ntal Rebound Angle, and the Vertical Rebound Angle F221913 37.1.1 Testballsshallbestoredinanenvironmentallycontrolledspaceforatleast14daysimmediatelybeforetesting.Woodbats shall be stored at these environmental conditions for at least 24 h prior to testing. Non-wood bats shall be stored at these tes
31、t environmental conditions for at least 2 h prior to testing. 7.1.2 Temperature is to be maintained at 72 6 4F (22 6 2C). 7.1.3 Relative humidity (RH) is to be maintained between 40 and 60%. 7.1.4 Temperature and relative humidity are to be measured and recorded hourly within 60.5F (60.3C) and 62% R
32、H over the conditioning and test duration. 8. Procedure 8.1 Determination of Bat Features and Test LocationDetermine bat balance point (BP) and bat MOI in accordance with Test Method F2398. 8.2 Select a performance measure (BBCOR, BESR, or BBS) as specied by the test sponsor. 8.3 Bat Test Procedure:
33、 8.3.1 Ready and calibrate ball speed gates in accordance with the manufacturers instructions. 8.3.1 Select a test ball meeting requirement of 5.1. Rotate the ball in the cannon between impacts so that the impact area of the ball is different for each impact. Record the actual values of compression
34、(Test Method weight of F1888), weight, size, and COR (Test Method F1887) of the ball. If the results are normalized, record the values of DS o and CCOR o (Test Method F2845) instead of COR and compression.). 8.3.2 Set ball cannon to re the ball at the desired test speed (60 to 150 mph) as determined
35、 by the test sponsor. 8.3.3 Mount the bat in the clamps of the bat pivot support. Locate the bat pivot to provide a ball impact near the maximum performance location (often 6 in. from the barrel end of the bat). 8.3.5 The ball impact must be centered vertically and horizontally on the bat diameter a
36、t the desired impact location. 8.3.4 Locate the bat against the start position reference to obtain a ball rebound perpendicular to the inbound ball line of travel (see Fig. 1). 8.3.7 Verify that all ball speed gates are reset and ready to take data. 8.3.5 Loadtheselectedtestballinballcannon.Orientth
37、etestballsothatitsimpactwiththebatwilloccurbetweenthestitches of the ball. 8.3.6 Shoot the ball at the bat, observing all safety precautions. 8.3.7 Verifyproperbatalignmentbyobservingthereboundpathoftheballafterimpactwiththebat.Thereboundangleshould be within 10 of the inbound path.Appendix X1 and A
38、ppendix X2 describe acceptable methods to measure the rebound path. 8.3.8 Record the ball inbound speed, ball rebound speed, and the bat rebound speed. For inbound speeds below 120 mph, the inbound speed must be within61 mph of the target speed. For inbound speeds above 120 mph, the inbound speed mu
39、st be within 62 mph of the target speed. 8.3.9 Calculate the ball rebound speed from the bat speed using: v r 5I1I pivot ! w mQ 2v i (1) where: Q = distance from the impact location and pivot point location, in. (mm), Q = distance from the impact location and pivot point location, in. (m), v r = bal
40、l rebound speed found from the bat speed, in./s (m/s), w = bat rotational speed, rad/s, I = moment of inertia (MOI) of bat, oz-in. 2 (kg-mm 2 ), as measured 6 in. (152 mm) from the knob end of the bat, I = moment of inertia (MOI) of bat (Test Method F2398), oz-in. 2 (kg-m 2 ), I pivot = moment of in
41、ertia of pivot stage, oz-in. 2 (kg-mm 2 ), I pivot = moment of inertia of pivot stage, oz-in. 2 (kg-m 2 ), v i = ball inbound speed, in./s (m/s), and m = weight of the test ball, oz (g). 8.3.10 Calculate the momentum ratio, L, using: L512 v i 2v r 1v r 1v i (2) where: L = 1 minus the ratio of the mo
42、mentum before impact divided by the momentum after impact, and L = the ratio of the momentum after impact divided by the momentum before impact minus one, and v r = ball rebound speed, in./s (m/s). For impacts where both the bat and ball rebound speeds are measured, check that the angular momentum a
43、bout the pivot is conserved. Do not use impacts where L 0.02. For recurring large L, check the ball rebound angle, I,Q,m, and I pivot . F221913 48.3.11 Each impact location on the bat must have six valid readings from six different balls.Record and store results from all impacts as requested by test
44、 sponsor. 8.3.12 Identify the maximum performance location by moving the impact location in 1 2-in. increments. The minimum performanceBBCOR on both sides of the peak must be at least 0.5% less than the peak performance. 9. Calculation of Results 9.1 BBCOR: 9.1.1 Calculate the bat-ball coefficient o
45、f restitution (BBCOR) for each valid impact using Eq 3 and Eq 4: BBCOR5 v i 1v r v i S m M e 11 D 21 (3) M e 5 I1I pivot Q 2 (4) 1 M e 5 1 W 1 (Q162BP) 2 12W(BP26) 2 (4) where: M e = effective bat mass, oz (g). M e = effective bat mass, oz (g), W = bat weight, oz (g), and BP = balance point (Test Me
46、thod F2398), in. (m). 9.1.2 Calculate the normalized BBCOR for each valid impact using Eq 5 and Eq 6: BBCOR N 5 r S CCOR S 2 11 11r S (5) r S 5 DS DS S 12BBCOR 2 BBCOR 2 2CCOR 2 (6) r S 5 DS DS S S 12BBCOR 2 BBCOR 2 2CCOR 2 11 D 21 (6) where: BBCOR N = normalized BBCOR, r S = ratio of bat stiffness
47、to the stiffness of a standard ball, DS = dynamic stiffness of the test ball, Test Method F2845 (lb/in), DS S = dynamic stiffness of the standard ball, provided by the test sponsor (lb/in), CCOR = cylindrical coefficient of restitution of the test ball, Test Method F2845, and CCOR S = cylindrical co
48、efficient of restitution of the standard ball, provided by the test sponsor. 9.1.3 Calculate the average BBCOR for the test bat from the six valid impacts using Eq 7: BBCOR avg 5 1 6 BBCOR 1 1BBCOR 2 11BBCOR 6 ! (7) 9.1.4 To obtain the bat performance using the bat speed, in Eq 3 replace v r with v
49、r (from Eq 1). 9.1.5 To normalize bat performance with the ball CCOR and DS, in Eq 7 replace BBCOR with BBCOR N (from Eq 5). 9.2 BESR: 9.2.1 Calculate the ball exit speed ratio (BESR) of the test bat normalized to a nominalstandard ball of mass, m 0s , using Eq 8: BESR5 BBCOR2 m s M g 11 m s M g 10.5 (8) BESR5 BBCOR2 m s M e 11 m s M e 10.5 (8) where: m s = weight of the standard ball, provided by the test sponsor, oz (kg). 9.2.2 Calculate the average BESR for the test bat from the six valid impacts using Eq 9: F22
