1、Designation: F2219 14 An American National StandardStandard Test Methods forMeasuring High-Speed Bat Performance1This standard is issued under the fixed designation F2219; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 A method for determining bat performance by measur-ing the bat-ball coefficient of restitution (BBCOR), derivingthe b
3、all exit speed ratio (BESR), and calculating a batted-ballspeed (BBS). It is applicable to baseball and softball bats ofany construction or material. The test methods provide quan-titative measures of bat dynamic performance that may be usedfor comparison purposes.1.2 The BBCOR, BESR, and BBS are ea
4、ch calculated frommeasurements taken in the laboratory on test equipmentmeeting the requirements defined in this standard.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information
5、 onlyand are not considered standard.1.4 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 practices and to determine theapplicability of regulatory li
6、mitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F1887 Test Method for Measuring the Coefficient of Resti-tution (COR) of Baseballs and SoftballsF1888 Test Method for Compression-Displacement of Base-balls and SoftballsF2398 Test Method for Measuring Moment of Inertia andCenter of P
7、ercussion of a Baseball or Softball BatF2845 Test Method for Measuring the Dynamic Stiffness(DS) and Cylindrical Coefficient of Restitution (CCOR) ofBaseballs and Softballs3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 balance point (BP), ndistance to the center of massfrom t
8、he knob end of the bat.3.1.2 ball exit speed ratio (BESR), nratio of ball exitspeed to the ball inbound speed plus12 .3.1.3 bat-ball coeffcient of restitution (BBCOR), nCORof a specific ball colliding with a bat.3.1.4 batted ball speed (BBS), nthe speed that a ballwould be hit off a bat in play base
9、d on given pitch and batspeeds.3.1.5 coeffcient of restitution (COR), nmeasure of impactefficiency calculated as the relative speed of the objects afterimpact divided by the relative speed of the objects beforeimpact.3.1.6 cylindrical coeffcient of restitution (CCOR), ntheratio of the rebound to inc
10、oming speed of a ball impacting asolid rigid cylinder.3.1.7 dynamic stiffness (DS), na normalized measure ofthe ball impact force having units of stiffness (lb/in. or kN/m).It is obtained by dividing the square of the peak force betweenthe ball and impact surface by the ball mass and the square ofth
11、e incoming ball speed.3.1.8 moment of inertia (MOI), nmeasure of mass distri-bution relative to an axis of rotation. It is the product of themass multiplied by the square of the distance to the mass,summed over the entire bat.3.1.9 test sponsor, ngroup, association or individual speci-fying test req
12、uirements including ball specifications, perfor-mance measure, and test speed.4. Significance and Use4.1 These test methods offer a laboratory means to quanti-tatively compare the performance of baseball and softball bats.4.2 Use of these test methods can provide quantitativemetrics of bat performan
13、ce.5. Apparatus and Equipment5.1 Test BallsBaseballs or softballs as determined by thetest sponsor.1These test methods are under the jurisdiction of ASTM Committee F08 onSports Equipment, Playing Surfaces, and Facilities and are the direct responsibilityof Subcommittee F08.26 on Baseball and Softbal
14、l Equipment.Current edition approved May 1, 2014. Published June 2014. Originallyapproved in 2002. Last previous edition approved in 2013 as F2219 13. DOI:10.1520/F2219-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For An
15、nual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 Ball specification values are to be recorded and tracedto individual
16、balls.5.2 Bat-Ball Test Apparatus:5.2.1 Ball CannonA device capable of shooting a ball atspeeds up to 220 ft/s (67.1 m/s, 150 mph). Balls shall beoriented to impact the strike surface between the stitches.Typical pitching machines cannot yield the aiming accuracyrequired by these test methods. Canno
17、n exhaust air must notcause motion of the bat in the absence of an impact.5.2.2 Ball Speed GateLight screens capable of measuringa ball traveling at speeds up to 220 ft/s (67.1 m/s, 150 mph),with an accuracy of at least 60.7 ft/s (60.2 m/s). The deviceshall measure across a length of no less than ha
18、lf the balldiameter to avoid centering error. The first sensor shall belocated no more than 12.0 in. (304.8 mm) from the bat surface.The second sensor shall be located 6 6 0.03 in. (152 6 0.8mm) after the first sensor (see Fig. 1). The ball speed gate mustmeasure the ball rebound speed.5.2.3 Ball An
19、gle MeasurementMeasure and record theball vertical and horizontal rebound angles within 1, using atleast one of the following or equivalent devices.5.2.3.1 Angled Light GatesA light trap device capable ofmeasuring the ball rebound angle after impact with a bat (seeFig. 2). The device shall measure a
20、cross a length of no less thanhalf the ball diameter to avoid centering error. The verticalrebound angle gate shall be mounted at approximately 45relative to the inbound ball path. The horizontal rebound anglegate shall be mounted at approximately 25 relative to theinbound ball path (to provide room
21、 for the speed gates).(Appendix X1.)5.2.3.2 High Speed CameraA high speed video cameracapable of recording the ball rebound path. If a mirror is placedat 45 atop the light box, one video camera can observe boththe horizontal and vertical planes. (Appendix X2.)5.2.4 Bat Pivot SupportA turntable, rota
22、ting in the hori-zontal plane, with clamps to support and align the bat in thepath of the ball. The rotating clamp and shaft assembly shallnot weigh more than 6 lb (2.7 kg) and shall spin freely via ballbearings (see Fig. 1). The MOI of the clamp turntable assemblyshall be determined, recorded, and
23、used in the performancecalculations. The MOI for the clamp turntable assembly shallnot exceed 300 oz-in.2(5498 kg-mm2).5.2.5 Bat Speed SensorDevice to measure bat rotationalspeed for at least 100 after impact. Device shall read speedsup to 3000/s with an accuracy of at least 1/s (found to beachievab
24、le using an optical encoder). Bat speed is taken fromthe slope of the linear least-squares fit to the bat rotation versustime data between 5 and 95 after impact.FIG. 1 Bat Testing MachineF2219 1426. Calibration and Standardization6.1 Ball Speed GateThe distance between the sensors ofthe speed gates
25、should be measured and recorded.6.2 Reference Standards and BlanksA standard bat andball shall be used for monthly reference purposes to verifyproper machine operation.6.3 Location Tolerance:6.3.1 BatCoat the impact area of the bat with a removablematerial (dry erase marker or powder).6.3.2 BallImpa
26、ct the bat with a solid coverless ball suchas a pitching machine baseball or softball core.6.3.3 LocationFor each impact, use the average of the ballcontact edges on the bat as the impact location. The impactlocation is the average location from six balls.6.3.4 ToleranceThe standard deviation of the
27、 six impactsmust be less than 0.125 in. The difference between the targetlocation and the average location from the six impacts must beless than 0.125 in.7. Conditioning7.1 Ball and Bat Conditioning and Test Room Conditions:7.1.1 Test balls shall be stored in an environmentallycontrolled space for a
28、t least 14 days immediately beforetesting. Wood bats shall be stored at these environmentalconditions for at least 24 h prior to testing. Non-wood batsshall be stored at these test environmental conditions for atleast 2 h prior to testing.7.1.2 Temperature is to be maintained at 72 6 4F (22 62C).7.1
29、.3 Relative humidity (RH) is to be maintained between40 and 60 %.7.1.4 Temperature and relative humidity are to be measuredand recorded hourly within 60.5F (60.3C) and 62%RHover the conditioning and test duration.8. Procedure8.1 Determination of Bat Features and Test LocationDetermine bat balance po
30、int (BP) and bat MOI in accordancewith Test Method F2398.8.2 Select a performance measure (BBCOR, BESR, orBBS) as specified by the test sponsor.8.3 Bat Test Procedure:8.3.1 Select a test ball meeting requirement of 5.1. Rotatethe ball in the cannon between impacts so that the impact areaof the ball
31、is different for each impact. Record the ball weight,compression (Test Method F1888), COR (Test Method F1887),and circumference. If the results are normalized, record thevalues of DS and CCOR (Test Method F2845).8.3.2 Set ball cannon to fire the ball at the desired test speed(60 to 150 mph) as deter
32、mined 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 maximumperformance location (often 6 in. from the barrel end of thebat).8.3.4 Locate the bat against the start position (see Fig. 1).8.3.5 Load the selected tes
33、t ball in ball cannon. Orient thetest ball so that its impact with the bat will occur between thestitches of the ball.FIG. 2 Diagram Showing Light Gate Arrangement to Measure the Ball Speed, the Horizontal Rebound Angle,and the Vertical Rebound AngleF2219 1438.3.6 Shoot the ball at the bat, observin
34、g all safety precau-tions.8.3.7 Verify proper bat alignment by observing the reboundpath of the ball after impact with the bat. The rebound angleshould be within 10 of the inbound path.8.3.8 Record the ball inbound speed, ball rebound speed,and the bat rebound speed. For inbound speeds below 120 mph
35、,the inbound speed must be within 61 mph of the target speed.For inbound speeds above 120 mph, the inbound speed must bewithin 62 mph of the target speed.8.3.9 Calculate the ball rebound speed from the bat speedusing:vr5 I1Ipivot!mQ2 vi(1)where:Q = distance from the impact location and pivot pointlo
36、cation, in. (m),vr= ball rebound speed found from the bat speed, in./s(m/s), = bat rotational speed, rad/s,I = moment of inertia (MOI) of bat (Test MethodF2398), oz-in.2(kg-m2),Ipivot= moment of inertia of pivot stage, oz-in.2(kg-m2),vi= ball inbound speed, in./s (m/s), andm = weight of the test bal
37、l, oz (g).8.3.10 Calculate the momentum ratio, L, using:L 5 1 2vivr2 vr1 vi!(2)where:L = the ratio of the momentum after impact divided by themomentum before impact minus one, andvr= ball rebound speed, in./s (m/s).For impacts where both the bat and ball rebound speeds aremeasured, check that the an
38、gular momentum about the pivot isconserved. Do not use impacts where L 0.02. For recurringlarge L, check the ball rebound angle, I, Q, m, and Ipivot.8.3.11 Record and store results from all impacts as re-quested by test sponsor.8.3.12 Identify the maximum performance location by mov-ing the impact l
39、ocation in12-in. increments. The minimumBBCOR on both sides of the peak must be at least 0.5 % lessthan the peak performance.9. Calculation of Results9.1 BBCOR:9.1.1 Calculate the bat-ball coefficient of restitution (BB-COR) for each valid impact using Eq 3 and Eq 4:BBCOR 5vi1vrviSmMe11D2 1 (3)1Me51
40、W1Q 1 6 2 BP!21 2 W BP 2 6!2#(4)where:Me= effective bat mass, oz (g),W = bat weight, oz (g), andBP = balance point (Test Method F2398), in. (m).9.1.2 To normalize bat performance for ball variation,calculate the normalized BBCOR for each valid impact usingEq 5 and Eq 6:BBCORN5 rSCCORS21111rS(5)rS5DS
41、DSSS1 2 BBCOR2BBCOR22 CCOR21 1D2 1 (6)where:BBCORN= normalized BBCOR,rS= ratio of bat stiffness to the stiffness of a standardball,DS = dynamic stiffness of the test ball, Test MethodF2845 (lb/in),DSS= dynamic stiffness of the standard ball, providedby the test sponsor (lb/in),CCOR = cylindrical coe
42、fficient of restitution of the testball, Test Method F2845, andCCORS= cylindrical coefficient of restitution of the stan-dard ball, provided by the test sponsor.9.1.3 Calculate the average BBCOR for the test bat from thesix valid impacts using Eq 7:BBCORavg516BBCOR11BBCOR211BBCOR6! (7)9.1.4 To obtai
43、n the bat performance using the bat speed, inEq 3 replace vrwith vr(from Eq 1).9.1.5 To normalize bat performance with the ball CCOR andDS, in Eq 7 replace BBCOR with BBCORN(from Eq 5).9.2 BESR:9.2.1 Calculate the ball exit speed ratio (BESR) of the testbat normalized to a standard ball of mass, ms,
44、 using Eq 8:BESR 5BBCOR 2msMe11msMe10.5 (8)where:ms= weight of the standard ball, provided by the testsponsor, oz (kg).9.2.2 Calculate the average BESR for the test bat from thesix valid impacts using Eq 9:BESRavg516BESR11BESR211BESR6! (9)9.3 BBS:9.3.1 Calculate the batted-ball speed (BBS) value of
45、the testbat using Eq 10:BBS 5 vpBESR 2 0.5!1vbBESR10.5! (10)where:vb= bat swing speed (mph or m/s) supplied by the testsponsor, andvp= ball pitch speed (mph or m/s), supplied by the testsponsor.9.3.2 Calculate the average batted ball speed (BBS) value ofthe test bat from the six valid impacts using
46、Eq 11:F2219 144BBSavg516BBS11BBS211BBS6! (11)10. Report10.1 Report the following information:10.1.1 Name of the test facility and test operator,10.1.2 Test date,10.1.3 Test equipment used for this test method,10.1.4 Test ball information in accordance with 5.1, includ-ing the weight, and, if normali
47、zing, the values m, CCOR, DS,CCORS, and DSS.10.1.5 Bat model, length, weight, MOI and BP tested, andany other pertinent data, such as, condition of the bat ormodification to the bat,10.1.6 MOI of bat pivot support,10.1.7 For each valid impact, ball inbound speed, ball exitspeed (if available), bat r
48、ebound speed (if available), impactlocation from the rotation point, and BBCOR, BESR or BBS,and10.1.8 Any and all unique observations, including but notexclusively, any damage to the bat or test ball, misdirected ballimpacts, and any odd noises or vibrations.11. Precision and Bias11.1 Precision and
49、bias evaluations have not been conductedfor these test methods. When such data are available, aprecision and bias section will be added.12. Keywords12.1 baseball bats; baseballs; bat performance; BBCOR;BBS; BESR; COR; softball bats; softballsAPPENDIXES(Nonmandatory Information)X1. MEASURE BALL REBOUND ANGLE USING LIGHT GATESX1.1 Calculate the distance from the bat to the closest speedgate from:d 5St42 t312RvrDS1vi11vrD(X1.1)X1.2 Calculate the rebound time from the bat to the verticalangle speed gate from:tz51vrd 2 2
