1、Designation: F1890 17 An American National StandardStandard Test Method forMeasuring Softball and Baseball Bat Performance Factor1This standard is issued under the fixed designation F1890; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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 A method for determining bat performance by measur-ing the bat-ball coefficient of restitution (BBCO
3、R) and derivingthe bat performance factor (BPF). It is applicable to softballand baseball bats of any construction or material. The methodprovides a quantitative measure of bat dynamic performancethat may be used for comparison purposes.1.2 The BBCOR and BPF are calculated from measure-ments taken i
4、n the laboratory on test equipment meeting therequirements defined in this method.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are units that areprovided for information only and are not considered standard.1.4 This standard does not purpor
5、t 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard
6、was developed in accor-dance with internationally 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. Refere
7、nced 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 Percussion of a Baseball or Softb
8、all 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 knob end of the bat.3.1.2 coeffcient of restitution (COR), nthe relative speedof the objects after impact divided by the relative speed of
9、theobjects before impact.3.1.3 bat-ball coeffcient of restitution (BBCOR), nCORof a specific ball colliding with a bat as defined in this testmethod.3.1.4 bat performance factor (BPF), nratio of BBCOR toball COR as defined in this test method.3.1.5 center of percussion (COP), nimpact location on the
10、bat that produces no reaction force at the pivot point and causesthe bat to rotate about the pivot point, taken 6 in. (152 mm)from the knob end of the bat.3.1.6 moment of inertia (MOI), nmeasure of mass distri-bution relative to a pivot point, taken 6 in. (152 mm) from theknob end of the bat.4. Sign
11、ificance and Use4.1 These test methods offer a laboratory means to quanti-tatively compare the performance of softball and baseball bats.5. Apparatus5.1 Test BallsSoftballs or baseballs as determined bythose specifying the bat test requirements and tested inaccordance with the following procedures.
12、Perform ball com-pression test of Test Method F1888 prior to ball COR test ofTest Method F1887.5.1.1 Softballs:5.1.1.1 Compression350 to 375 lb (1557 to 1688 N) (TestMethod F1888.)5.1.1.2 Weight6.25 to 6.75 oz (177.2 to 191.4 g).5.1.1.3 Size12.00 to 12.25-in. (304.8 to 311.1-mm) cir-cumference (Test
13、 Method F1888).5.1.1.4 Ball COR0.465 to 0.475 (Test Method F1887).5.1.2 Baseballs:5.1.2.1 Compression175 to 200 lb (778 to 890 N) (TestMethod F1888 using 0.20 in. (5.08 mm) deflection).5.1.2.2 Weight5.00 to 5.25 oz (141.8 to 148.8 g).5.1.2.3 Size9.00 to 9.50 in. (228.6 to 241.3 mm) circum-ference (T
14、est Method F1888).1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility ofSubcommittee F08.26 on Baseball and Softball Equipment.Current edition approved Aug. 15, 2017. Published January 2018. Originall
15、yapproved in 1998. Last previous edition approved in 2011 as F1890 11. DOI:10.1520/F1890-17.2For 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 S
16、ummary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Princip
17、les for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.1.2.4 Ball COR0.545 to 0.555 (Test Method F1887).5.2 Bat-Ball COR Test Apparatus:5.2.1 Ball CannonA device capable of shooting a ball at
18、 aspeed of at least 88 ft/s (26.8 m/s). The ball shall not have aspin rate in excess of 10 rpm. Typical pitching machines cannotyield the aiming accuracy required by this test method. Cannonexhaust air must not cause motion of the bat in the absence ofan impact. The ball cannon can be any distance f
19、rom impactlocation, as long as it can meet the ball aim requirements andprovide six valid impacts in twelve shots or less.5.2.2 Bat Speed GateA light-trap device, or an equivalent,capable of measuring an edge traveling at speeds of between 5and 15 ft/s with a resolution of 0.01 ft/s (0.003 m/s) and
20、anaccuracy of at least 61 %. The first sensor shall trigger afterthe bat rotates between 5 to 10 from its start position. Thesecond sensor shall trigger 30 to 35 after the second sensor.Reference Fig. 1.5.2.2.1 Optional Bat Speed SensorDevice to measure batrotational speed for at least 100 after imp
21、act. Device shall readspeeds up to 3000/s with an accuracy of at least 1/s (found tobe achievable using an optical encoder). Bat speed is takenfrom the slope of the linear least-squares fit to the bat rotationangle versus time data between 5 and 95 after impact.5.2.3 Ball Speed GateA light-trap devi
22、ce, or anequivalent, capable of measuring a sphere traveling at speedsin excess of 88 ft/s (26.8 m/s) with an accuracy of 0.5 ft/s (0.2m/s) or better. The device shall measure across a length of noless than half the ball diameter to avoid centering error. Thedistance between the two sensors shall be
23、 determined to within60.03 in. (60.76 mm) and must be between 6 and 12 in. (152and 305 mm). Prior to impact, the sensor closest to the bat mustbe between 4 and 6 in. (102 and 152 mm) from the bat.Reference Fig. 1.5.2.4 Bat Pivot SupportA turntable, rotating in the hori-zontal plane, with clamps to s
24、upport and align the bat in thepath of the ball. The clamp surfaces shall be a 45 v-clamp witha radius no greater than 2.0 in. (50.8 mm). The rotating clampand shaft assembly shall not weigh more than 6 lb (2.7 kg) andshall spin freely via ball bearings (see Fig. 1). The polar MOIfor the clamp turnt
25、able assembly shall not exceed 300 oz-in.2(5498 kg-mm2).6. Calibration and Standardization6.1 Ball Speed GateThe distances between the sensors ofthe speed gates must be measured and recorded to the statedtolerances. The accuracy of the timers used in the velocitysensors must be adequate to provide t
26、he stated velocityaccuracy at maximum stated speeds. The timers used shall becalibrated on at least a yearly basis.6.2 Reference Standards and BlanksA standard bat andball shall be used for reference purposes to verify propermachine operation.6.3 Calibration:6.3.1 Determine the balance point (BP), M
27、OI, and COP of alarge calibration mass (MOI 30 000 oz-in.2(549 000 kg-mm2) in accordance with Test Method F2398.6.3.2 Mount the large calibration mass in the bat pivotsupport clamps per 8.2.4.6.3.3 Select a test ball in accordance with 5.1 as determinedby those specifying the bat test, and record th
28、e actual values ofcompression, weight, size, and COR of the ball in accordancewith 5.1.6.3.4 Shoot the ball at the calibration mass COP, observingthe necessary safety precautions and in accordance withSection 8 except as noted.6.3.5 Determine Kcalibrationas follows:Kcalibration511Ball CORS1 1I1IpmR2
29、 DStdDSDTDSRrD511Ball CORS1 1I1IpmR2 DSVbatviD(1)where:Ball COR = ball COR (Test Method F1887) of the ball usedin each impact,I = moment of inertia (MOI) of mass, Test MethodF2398, oz-in.2(kg-m2),Ip= moment of inertia (MOI) of bat pivot, oz-in.2(kg-m2),R = COP distance, Test Method F2398, in. (m),r
30、= radius to bat speed sensors, in. (m),T = time for bat to travel through bat speed sensors,s,FIG. 1 Bat Testing MachineF1890 172t = time for ball to travel through ball speedsensors, s,D = distance between bat speed sensors, in. (m),d = distance between ball speed sensors, in. (m),vi= ball inbound
31、speed, in./s (m/s),Vbat= bat recoiling speed at the impact location, in./s(m/s), andm = weight of the test ball used in each impact, oz(g).6.3.6 Calculate the average Kcalibrationfor the calibrationmass from six valid impacts.6.3.7 The average Kcalibrationmust fall between 0.98 and1.02. If average K
32、calibrationis out of range, check ball and batspeed gates, Ball COR, I, R, m, Ipivot.7. Conditioning7.1 Ball and Bat Conditioning and Test Room Conditions:7.1.1 Test balls shall be placed in an environmentallycontrolled space for at least 14 days immediately beforetesting. Wood bats shall be stored
33、at these environmentalconditions for at least 24 h prior to testing. Non-wood batsshall be stored at these environmental conditions for at least 2h prior to testing.7.1.2 Temperature is to be maintained at 72 6 4F (22 62C).7.1.3 Relative humidity is to be maintained between 40 and60 %.7.1.4 Temperat
34、ure and relative humidity are to be measuredand recorded hourly within 60.5F (60.3C) and 62%RHover conditioning and test duration.8. Procedure8.1 Determination of Bat Features and Test LocationDetermine bat balance point (BP), bat MOI, and bat COP inaccordance with Test Method F2398.8.2 Bat Test Pro
35、cedure:8.2.1 Ready and calibrate ball and bat speed gates inaccordance with the manufacturers instructions.8.2.2 Select a test ball in accordance with 5.1, and record theactual values of compression, weight, size, and COR of the ballin accordance with 5.1.8.2.3 Set ball cannon to fire the ball at th
36、e desired impactspeed of 88 ft/s (26.8 m/s). Valid test speeds are considered tobe those within 61 % of the targeted test speed.8.2.4 Mount bat in the clamps on the bat pivot support. Theknob end of the bat must be 6 6 0.03 in. (152.4 6 0.76 mm)from the axis of rotation of the turntable assembly. Im
37、pactlocation(s) to be determined by those specifying the testrequirements.8.2.5 The ball impact must be centered vertically andhorizontally on the bat at the desired impact location.8.2.6 Locate the bat against the start position reference toobtain a ball rebound parallel to the inbound ball line of
38、 travel.(See Fig. 1.)8.2.7 Verify that all speed sensors are reset and ready to takedata.8.2.8 Orient the test ball in ball cannon so that its impactwith the bat will occur between the stitches of the ball.8.2.9 Shoot the ball at the bat, observing the necessarysafety precautions.8.2.10 Record ball
39、inbound speed and bat rebound speed.8.2.10.1 OptionalRecord ball rebound speed. The ballrebound angle immediately after impact should be within 610of the inbound ball path.8.2.11 Six valid impact readings are required per impactlocation. For a given test ball, rotate the ball in the cannonbetween im
40、pacts so that the impact area of the ball is differentfor each impact.8.2.11.1 If identifying maximum performance is desired, theperformance at the peak location should be at least 0.5 %greater than the performance at the adjacent bat axial locations.9. Calculation of Results9.1 Calculate the BBCOR
41、for each valid impact using Eq 2:BBCORbat out5S1 1MemDStdDSDTDSQrD2 1 (2)where:Me5I1IpQ2(3)and:Me= effective mass of a pivoted bat, oz (g),I = moment of inertia (MOI) of bat, Test Method F2398,oz-in.2(kg-m2),Ip= moment of inertia (MOI) of bat pivot, oz-in.2(kg-m2),andQ = distance from the impact loc
42、ation to the pivot pointlocation, in. (m).9.2 Calculate the BPF for each valid impact using Eq 4:BPFbat out5BBCORbat outBall COR(4)9.3 Calculate the average BPF for the test bat from the sixvalid impacts as follows:9.3.1 For baseball bats, calculate the average BPF using Eq5.BPFbat out avg!5 (5)BPFb
43、at out!11 BPFbat out!21 1 BPFbat out!6!69.3.2 For softball bats, calculate the average BPF using Eq6.BPFbat out avg!5 (6)BPFbat out!11 BPFbat out!21 1 BPFbat out!6!62 0.0510. 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
44、 measurements of test conditions, including:10.1.3.1 Humidity and temperature of the ball and batconditioning and test room environments,F1890 17310.1.3.2 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 acco
45、rdance with 5.1, includ-ing the compression, weight, size, and COR of the test ball,10.1.6 Bat model, length, weight tested, and any otherpertinent data, such as condition of the bat or modification tothe bat,10.1.7 Bat MOI, BP, and COP, and MOI of the bat pivotsupport,10.1.8 For each impact (includ
46、ing invalid impacts) ballinbound speed, bat rebound speed, BBCOR, and BPF,10.1.9 Any and all unique observations including, but notexclusively, any damage to the bat or test ball, misdirected ballimpacts, and any odd noises or vibrations, and10.1.10 Calibration certificate numbers for measurementdev
47、ices and velocity timers and date of last calibration.11. Precision and Bias11.1 Precision and bias evaluations have not been conductedfor this test method. When such data are available, a precisionand bias section will be added.12. Keywords12.1 baseball bats; baseballs; bat performance; BBCOR;BPF;
48、COR; softball bats; softballsAPPENDIX(Nonmandatory Information)X1. CALCULATING BAT PERFORMANCE FACTOR (ALTERNATE TEST METHOD)X1.1 Calculate the BBCOR and BPF using the actual size,weight, compression, and COR of the ball used in each of thesix valid impacts.X1.1.1 Calculate the bat-ball coefficient
49、of restitution foreach valid impact as:BBCORbat out5S1 1MemDVbatvi2 1 (X1.1)andBBCORball out5vi1vrviSmMe1 1D2 1 (X1.2)whereMe5I1IpQ2(X1.3)X1.1.1.1 Optional MethodCalculate ball rebound speedfrom the bat speed using:vr5 I 1 Ip!SmQD2 vi5 I 1 Ip!SvbatmQ2D2 vi(X1.4)X1.1.1.2 To obtain the bat performance using optionalmethod (vrper Eq X1.4), in Eq X1.2 replace vrwith vr.and:BBCORbat out= bat-ball coefficient of restitution using thebat rebound speed,BBCORball out= bat-ball coefficient of restitution using theball rebound
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