1、Designation: F2219 11An 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 ba
3、ll 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 eac
4、h 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 lim
6、itations 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 ofBaseballs and SoftballsF2398 Test Method for Measuring Moment of Inertia andCenter of Perc
7、ussion 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 the
8、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 based o
9、n 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 incomi
10、ng 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 ofthe i
11、ncoming 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 individualspecifying test requirem
12、ents including ball specifications, per-formance measure, and test speed.4. Significance and Use4.1 These test methods offer a laboratory measure of theperformance of baseball and softball bats.4.2 Use of these test methods can provide quantitativemetrics of bat performance.5. Apparatus and Equipmen
13、t5.1 Test BallsBaseballs or softballs as determined by thetest sponsor.5.1.1 Ball specification values are to be recorded and tracedto individual 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
14、 to impact the strike surface between the stitches.Typical pitching machines cannot yield the aiming accuracy1These test methods are under the jurisdiction of ASTM Committee F08 onSports Equipment and Facilities and are the direct responsibility of SubcommitteeF08.26 on Baseball and Softball Equipme
15、nt.Current edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2002. Last previous edition approved in 2010 as F2219 10. DOI:10.1520/F2219-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
16、 Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.required by these test methods. Cannon exhaust air must notcause motion of the
17、 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 half the balldiameter to avoid centering er
18、ror. 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 Angle MeasurementUse one of the followingde
19、vices to measure and record the ball vertical and horizontalrebound angles within 1.5.2.3.1 Angled Light GatesA light trap device capable ofmeasuring the ball rebound angle after impact with a bat (seeFig. 2). The device shall measure across a length of no less thanhalf the ball diameter to avoid ce
20、ntering 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 for the speed gates).5.2.3.2 High-Speed CameraA high-speed vide
21、o 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.5.2.4 Bat Pivot SupportA turntable, rotating in the hori-zontal plane, with clamps to support and align the bat in thepath of the bal
22、l. 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 used in the performancecalculations. The MOI for the clamp turntable assembly shallnot exceed
23、 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 beachievable using an optical encoder). Bat speed is taken fromthe slope of the linear least-squares fi
24、t to the bat rotation versustime data between 5 and 95 after impact.6. Calibration and Standardization6.1 Ball Speed GateThe distance between the sensors ofthe speed gates should be measured and recorded. The timersused for speed measurements should be calibrated on at least ayearly basis.6.2 Refere
25、nce Standards and BlanksA standard bat andball shall be used for reference purposes to verify propermachine operation.6.3 Location Tolerance:6.3.1 BatCoat the impact area of the bat with a removablematerial (dry erase marker or powder).FIG. 1 Bat Testing MachineF2219 1126.3.2 BallImpact the bat with
26、 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 six impactsmus
27、t 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 at least 14 days
28、 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).7.1.3 Relative hum
29、idity (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 point (BP) and ba
30、t 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 Ready and calibrate ball speed gates in accordancewith the manufacturers instructions.8.3.2 Select a test ball meeting requirement of 5.1. Rot
31、atethe ball in the cannon between impacts so that the impact areaof the ball is different for each impact. Record the actual valuesof compression (Test Method F1888), weight, size, and COR(Test Method F1887) of the ball. If the results are normalized,record the values of DSoand CCORo(Test Method F28
32、45)instead of COR and compression.8.3.3 Set ball cannon to fire the ball at the desired test speed(60 to 150 mph) as determined by the test sponsor.8.3.4 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 i
33、n. from the barrel end of thebat).8.3.5 The ball impact must be centered vertically andhorizontally on the bat diameter at the desired impact location.8.3.6 Locate the bat against the start position reference toobtain a ball rebound perpendicular to the inbound ball line oftravel (see Fig. 1).8.3.7
34、Verify that all ball speed gates are reset and ready totake data.8.3.8 Load the selected test ball in ball cannon. Orient thetest ball so that its impact with the bat will occur between thestitches of the ball.8.3.9 Shoot the ball at the bat, observing all safety precau-tions.FIG. 2 Diagram Showing
35、Light Gate Arrangement to Measure the Ball Speed, the Horizontal Rebound Angle,and the Vertical Rebound AngleF2219 1138.3.10 Verify proper bat alignment by observing the re-bound path of the ball after impact with the bat. The reboundangle should be within 10 of the inbound path. Appendix X1and Appe
36、ndix X2 describe acceptable methods to measure therebound path.8.3.11 Record the ball inbound speed, ball rebound speed,and the bat rebound speed. For inbound speeds below 120 mph,the inbound speed must be within 61 mph of the target speed.For inbound speeds above 120 mph, the inbound speed must bew
37、ithin 62 mph of the target speed.8.3.12 Calculate the ball rebound speed from the bat speedusing:vr85 I 1 Ipivot!vmQ vi(1)where:Q = distance from the impact location and pivot pointlocation, in. (mm),vr8= ball rebound speed found from the bat speed, in./s(m/s),v = bat rotational speed, rad/s,I = mom
38、ent of inertia (MOI) of bat, oz-in.2(kg-mm2),as measured 6 in. (152 mm) from the knob end ofthe bat,Ipivot= moment of inertia of pivot stage, oz-in.2(kg-mm2),vi= ball inbound speed, in./s (m/s), andm = weight of the test ball, oz (g).8.3.13 Calculate the momentum ratio, L, using:L 5 1vivr1 vr1 vi(2)
39、where:L = 1 minus the ratio of the momentum before impactdivided by the momentum after impact, andvr= ball rebound speed, in./s (m/s).For impacts where both the bat and ball rebound speeds aremeasured, check that the angular momentum about the pivot isconserved. Do not use impacts where L 0.02. For
40、recurringlarge L, check the ball rebound angle, I, Q, m, and Ipivot.8.3.14 Each impact location on the bat must have six validreadings from six different balls.8.3.15 Identify the maximum performance location by mov-ing the impact location in12-in. increments. The minimumperformance on both sides of
41、 the peak must be at least 0.5 %less than 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 5vi1 vrviSmMe1 1D 1 (3)Me5I 1 IpivotQ2(4)where:Me= effective bat mass, oz (g).9.1.2 Calcu
42、late the normalized BBCOR for each validimpact using Eq 5 and Eq 6:BBCORN5rSCCORS21 11 1 rS(5)rS5DSDSS1BBCOR2BBCOR2 CCOR2(6)where:BBCORN= normalized BBCOR,rS= ratio of bat stiffness to the stiffness of astandard ball,DS = dynamic stiffness of the test ball, Test MethodF2845 (lb/in),DSS= dynamic stif
43、fness of the standard ball, pro-vided by the test sponsor (lb/in),CCOR = cylindrical coefficient of restitution of the testball, Test Method F2845, andCCORS= cylindrical coefficient of restitution of thestandard ball, provided by the test sponsor.9.1.3 Calculate the average BBCOR for the test bat fr
44、om thesix valid impacts using Eq 7:BBCORavg516BBCOR11 BBCOR21 . 1 BBCOR6! (7)9.1.4 To obtain the bat performance using the bat speed, inEq 3 replace vrwith vr8(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 Calculat
45、e the ball exit speed ratio (BESR) of the testbat normalized to a nominal ball of mass, m0, using Eq 8:BESR 5BBCOR msMg1 1msMg1 0.5 (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:BE
46、SRavg516BESR11 BESR21 . 1 BESR6! (9)9.3 BBS:9.3.1 Calculate the batted-ball speed (BBS) value of the testbat using Eq 10:BBS 5 vpBESR 0.5! 1 vbBESR 1 0.5! (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 C
47、alculate the average batted ball speed (BBS) value ofthe test bat from the six valid impacts using Eq 11:BBSavg516BBS11 BBS21 . 1 BBS6! (11)10. Report10.1 Report the following information:10.1.1 Name of the test facility and test operator,F2219 11410.1.2 Test date,10.1.3 Hourly measurements of test
48、conditions, including:10.1.3.1 Relative humidity and temperature of the ball andbat conditioning and test room environments,10.1.3.2 Number of hours ball and bat were in conditioningenvironment.10.1.4 Test equipment used for this test method,10.1.5 Test ball information in accordance with 5.1, inclu
49、d-ing the compression, weight, size, and COR of the test ball, andif normaling the values mo, CCORo, DSO, CCORS, and DSS.10.1.6 Bat model, length, weight, MOI and BP tested, andany other pertinent data, such as, condition of the bat ormodification to the bat,10.1.7 MOI of bat pivot support,10.1.8 For each impact (including invalid impacts) ballinbound speed, ball exit speed (if available), bat rebound speed(if available), impact location from the rotation point, andBBCOR, BESR or BBS,10.1.9 Any and all unique observatio
