1、Designation: F2219 10An 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 Bat3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 balance point (BP), ndistance to the center of massof a bat when measured from the distal end of the bat.3.1.2 ball exit speed (vr), noutbound speed of a ballfollowing impact with a bat as defi
8、ned in these test methods.3.1.3 ball exit speed ratio (BESR), nratio of ball exitspeed (vr) to ball inbound speed (vi) plus12 , as determined bythese test methods.3.1.4 ball inbound speed (vi), ninbound speed of a ballprior to impact with a bat as defined in this test method.3.1.5 bat-ball coeffcien
9、t of restitution (BBCOR)COR of aspecific ball colliding with a bat as defined in these testmethods. See coeffcient of restitution (COR).3.1.6 coeffcient of restitution (COR), nmeasure of impactefficiency calculated as the relative speed of the objects afterimpact divided by the relative speed of the
10、 objects beforeimpact.3.1.7 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.4. Significance and Use4.1 These test methods offer a laboratory measure o
11、f theperformance of baseball and softball bats.4.2 Use of these test methods can provide quantitativemetrics of bat performance.5. Apparatus and Equipment5.1 Test BallsBaseballs or softballs as determined bythose specifying the test requirements.5.2 Balls specification values are to be recorded and
12、tracedto individual balls.5.3 Bat-Ball Test Apparatus:5.3.1 Ball CannonA device capable of shooting a ball atspeeds up to 220 ft/s (67.1 m/s, approximately 150 mph). Ballsshall be oriented to impact the strike surface between thestitches. Typical pitching machines cannot yield the aimingaccuracy req
13、uired by these test methods. Cannon exhaust airmust not cause motion of the bat in the absence of an impact.5.3.2 Ball Speed GateLight screens capable of measuringa ball traveling at speeds up to 220 ft/s (67.1 m/s, approxi-mately 150 mph), with an accuracy of at least 60.7 ft/s (0.21These test meth
14、ods are under the jurisdiction of ASTM Committee F08 onSports Equipment and Facilities and are the direct responsibility of SubcommitteeF08.26 on Baseball and Softball Equipment.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 2002. Last previous edition approved in 2
15、009 as F2219 09. DOI:10.1520/F2219-10.2For 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.1Copyright ASTM Interna
16、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.m/s). The device shall measure across a length of no less thanhalf the ball diameter to avoid centering error. The first sensorshall be located no more than 12.0 in. (304.8 mm) from the batsurface. The second
17、 sensor shall be located 6 6 0.03 in. (1526 0.8 mm) after the first sensor (see Fig. 1). The ball speedgate must measure the ball rebound speed.5.3.3 Bat Pivot SupportA turntable, rotating in the hori-zontal plane, with clamps to support and align the bat in thepath of the ball. The rotating clamp a
18、nd shaft assembly shallnot weigh more than 6 lb (2.7 kg) and shall spin freely via ballbearings (see Fig. 1). The actual MOI of the clamp turntableassembly shall be determined, recorded, and used in theperformance calculations. The polar MOI for the clamp turn-table assembly shall not exceed 300 oz-
19、in.2(5498 kg-mm2).5.4 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 fit to the b
20、at 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 Reference Standa
21、rds and BlanksA standard bat andball shall be used for reference purposes to verify propermachine operation.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 immediately beforetesting. Woo
22、d 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 humidity (RH) is to be maintained
23、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 bat MOI in accordancewith Test Me
24、thod F2398.8.2 Select a performance variable (BBCOR, BESR, or BBS)to calculate. The choice of performance variable is left to thosespecifying the test requirements.8.3 Bat Test Procedure:8.3.1 Ready and calibrate ball speed gates in accordancewith the manufacturers instructions.8.3.2 Select six test
25、 balls meeting requirement of 5.1, andrecord the actual values of compression, weight, size, and CORof the ball.8.3.3 Set ball cannon to fire the ball at the desired test speed(60 to 150 mph) as determined by those specifying the testrequirements.FIG. 1 Bat Testing MachineF2219 1028.3.4 Mount the ba
26、t 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 distal 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 th
27、e bat against the start position reference toobtain a ball rebound perpendicular to the inbound ball line oftravel (see Fig. 1).8.3.7 Verify that all ball speed gates are reset and ready totake data.8.3.8 Load the selected test ball in ball cannon. Load the testball so that its impact with the bat w
28、ill occur between thestitches of the ball.8.3.9 Shoot the ball at the bat, observing the necessarysafety precautions.8.3.10 Verify proper bat alignment by observing the re-bound path of the ball after impact with the bat. The ballrebound angle immediately after impact should be within 65of the inbou
29、nd path. At slow ball rebound speeds the effects ofgravity can be large, as shown in Fig. 2. Thus, the spatial limitsfor a valid rebound are speed-dependent.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
30、within 61 mph of the target speed.For inbound speeds above 120 mph, the inbound speed must bewithin 62 mph of the target speed.8.3.12 Calculate the ball rebound speed from the bat speedusing:vr5 I 1 Ipivot!vmQ vi(1)where:Q = distance from the impact location and pivot pointlocation, in. (mm),vr= bal
31、l rebound speed found from the bat speed, in./s(m/s),v = bat rotational speed, rad/s,I = moment of inertia (MOI) of bat, oz-in.2(kg-mm2),as measured 6 in. (152 mm) from the base of theknob,Ipivot= moment of inertia of pivot stage, oz-in.2(kg-mm2),vi= ball inbound speed, in./s (m/s),vr= ball rebound
32、speed, in./s (m/s), andm = weight of ball used in each impact, oz (g).8.3.13 For impacts where both the bat and ball reboundspeeds are measured, check that the angular momentum aboutthe pivot is conserved. Do not use impacts where vrand vrdiffer by more than 10 %. For recurring large differencesbetw
33、een vrand vr, check the ball rebound angle, I, Q, m, andIpivot.8.3.14 Six valid readings are required per impact location.For a given test ball, rotate the ball in the cannon betweenimpacts so that the impact area of the ball is different for eachimpact.8.3.15 Identify the maximum performance locati
34、on by mov-ing the impact location in12-in. increments. The performanceat the peak location must be at least 0.5 % greater than theperformance at the adjacent locations.9. Calculation of Results9.1 BBCOR:9.1.1 Calculate the bat-ball coefficient of restitution (BB-COR) for each valid impact using Eq 2
35、 and Eq 3:BBCOR 5vi1 vrviSmMe1 1D 1 (2)Me5I 1 IpivotQ2(3)where:Q = distance from the impact location and pivot pointlocation, in. (mm),Me= effective bat mass, oz (g),I = moment of inertia (MOI) of bat, oz-in.2(kg-mm2),as measured 6 in. (152 mm) from the base of theknob,Ipivot= moment of inertia of p
36、ivot stage, oz-in.2(kg-mm2),vi= ball inbound speed, in./s (m/s),vr= ball rebound speed, in./s (m/s), andm = weight of ball used in each impact, oz (kg).9.1.2 Calculate the average BBCOR for the test bat from thesix valid impacts using Eq 4:BBCORavg516BBCOR11 BBCOR21 . 1 BBCOR6! (4)9.1.3 To obtain th
37、e bat performance using the bat speed, inEq 2 replace vrwith vr(from Eq 1).NOTEBat-ball impact is atx=0.Lines for each speed represent limittrajectories for impact rebound angles of 65.FIG. 2 Examples of Ball Rebound PathsF2219 1039.2 BESR:9.2.1 Calculate the ball exit speed ratio (BESR) of the test
38、bat normalized to a nominal ball of mass, m0, the specificationsof which must be supplied by the group or individual seekingto calculate BESR, using Eq 5, where symbols are defined inEq 2:BESR 5BBCOR m0/ Me1 1 m0/ Me1 0.5 (5)where:m0= nominal weight of ball specified by user or group, oz(kg).9.2.2 C
39、alculate the average BESR for the test bat from thesix valid impacts using Eq 6:BESRavg516BESR11 BESR21 . 1 BESR6! (6)9.3 BBS:9.3.1 Calculate the batted-ball speed (BBS) value of the testbat using Eq 7:BBS 5 vpBESR 0.5! 1 vbBESR 1 0.5! (7)where:vb= bat swing speed (mph) at the point of impact, which
40、must be supplied by the individual or group seeking tocalculate BBS, andvp= ball pitch speed (mph), which must be supplied by theindividual or group seeking to calculate BBS.9.3.2 Calculate the average batted ball speed (BBS) value ofthe test bat from the six valid impacts using Eq 8:BBSavg516BBS11
41、BBS21 . 1 BBS6! (8)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 Hourly measurements of test conditions, including:10.1.3.1 Relative humidity and temperature of the ball andbat conditioning and test room environments,10.1.3
42、.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, includ-ing the compression, weight, size, and COR of the test ball, andnormalization values moand CORo,10.1.6 Bat model, length, weight
43、 tested, and any otherpertinent data, such as, condition of the bat or modification tothe bat,10.1.7 Bat MOI, BP, and 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 t
44、he rotation point, BBCORand BESR,10.1.9 BESRavg,10.1.10 If desired, individual and average BBS results andthe bat swing speed and ball pitch speed used to calculate BBS,10.1.11 Any and all unique observations, including but notexclusively, any damage to the bat or test ball, misdirected ballimpacts,
45、 and any odd noises or vibrations, and10.1.12 Calibration certificates for measurement devicesand velocity timers.11. Precision and Bias11.1 Precision and bias evaluations have not been conductedfor these test methods. When such data are available, aprecision and bias section will be added.12. Keywo
46、rds12.1 baseball bats; baseballs; bat performance; BBCOR;BBS; BESR; COR; softball bats; softballsAPPENDIX(Nonmandatory Information)X1. TEST REPORTX1.1 See Table X1.1.F2219 104ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentio
47、nedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee an
48、d must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting o
49、f theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or servicea
