1、Designation: F1890 171An 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.1NOTEEditorially corrected 5.2.2 in February 2018.1. Scope1.1 A method for determining bat performance by measur
3、-ing the bat-ball coefficient of restitution (BBCOR) 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
4、 and BPF are calculated from measure-ments taken in 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 con
5、sidered 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, health, and environmental practices and deter-mine the applicability of regulatory limitat
6、ions prior to use.1.5 This international standard 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 Te
7、chnicalBarriers to Trade (TBT) Committee.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 Iner
8、tia andCenter of Percussion 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 knob end of the bat.3.1.2 coeffcient of restitution (COR), nthe relative speedof the obje
9、cts after impact divided by the relative speed of 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 c
10、enter of percussion (COP), nimpact location on thebat 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
11、6 in. (152 mm) from theknob end of the bat.4. Significance 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 t
12、ested inaccordance with the following procedures. 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
13、12.25-in. (304.8 to 311.1-mm) cir-cumference (Test Method F1888).5.1.1.4 Ball COR0.465 to 0.475 (Test Method F1887).5.1.2 Baseballs:1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility ofSubcommittee F
14、08.26 on Baseball and Softball Equipment.Current edition approved Aug. 15, 2017. Published January 2018. Originallyapproved in 1998. Last previous edition approved in 2011 as F1890 11. DOI:10.1520/F1890-17E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
15、er Service at serviceastm.org. For Annual 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 StatesThis international standard was develop
16、ed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.1.2.1 Compression17
17、5 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 (Test Method F1888).5.1.2.4 Ball COR0.545 to 0.555 (Test Method F1887).5.2 Bat-Ball COR Test Apparatus:5.
18、2.1 Ball CannonA device capable of shooting a ball at 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 absen
19、ce ofan impact. The ball cannon can be any distance from 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 GateAlight-trap device, or an equivalent,capable of measuring an edge traveling at speeds of between 5and 15
20、ft/s with a resolution of 0.01 ft/s (0.003 m/s) and 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 first sensor.Reference Fig. 1.5.2.2.1 Optional Bat Speed SensorDevice to mea
21、sure batrotational speed for at least 100 after impact. 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
22、after impact.5.2.3 Ball Speed GateA light-trap device, 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
23、error. Thedistance between the two sensors shall be 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,
24、rotating in the hori-zontal plane, with clamps to support 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 bear
25、ings (see Fig. 1). The polar MOIfor the clamp turntable 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 i
26、n the velocitysensors must be adequate to provide the 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 Ca
27、libration:6.3.1 Determine the balance point (BP), MOI, 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 determ
28、inedby those specifying the bat test, and record the 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 Kcalib
29、rationas follows:Kcalibration511Ball CORS1 1I1IpmR2 DStdDSDTDSRrD511Ball CORS1 1I1IpmR2 DSVbatviD(1)where:Ball COR = ball COR (Test Method F1887) of the ball usedin each impact,FIG. 1 Bat Testing MachineF1890 1712I = moment of inertia (MOI) of mass, Test MethodF2398, oz-in.2(kg-m2),Ip= moment of ine
30、rtia (MOI) of bat pivot, oz-in.2(kg-m2),R = COP distance, Test Method F2398, in. (m),r = radius to bat speed sensors, in. (m),T = time for bat to travel through bat speed sensors,s,t = time for ball to travel through ball speedsensors, s,D = distance between bat speed sensors, in. (m),d = distance b
31、etween ball speed sensors, in. (m),vi= ball inbound 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 Kcal
32、ibrationmust fall between 0.98 and1.02. If average Kcalibrationis 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 i
33、mmediately beforetesting. Wood bats shall be stored 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 i
34、s to be maintained between 40 and60 %.7.1.4 Temperature 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
35、inaccordance with Test Method F2398.8.2 Bat Test Procedure: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 w
36、ith 5.1.8.2.3 Set ball cannon to fire the ball at the 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)fro
37、m the axis of rotation of the turntable assembly. Impactlocation(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
38、 a ball rebound parallel to the inbound ball line of 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
39、 the necessarysafety precautions.8.2.10 Record ball 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 give
40、n test ball, rotate the ball in the cannonbetween impacts 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 locatio
41、ns.9. Calculation of Results9.1 Calculate the BBCOR 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
42、, oz-in.2(kg-m2),andQ = distance from the impact location 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, calculat
43、e the average BPF using Eq5.BPFbat out avg!5 (5)BPFbat 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 0.05F1890 171310. Report10.1 Report the following information:10.1.1 Name of the
44、test facility and test operator,10.1.2 Test date,10.1.3 Hourly measurements of test conditions, including:10.1.3.1 Humidity and temperature of the ball and batconditioning and test room environments,10.1.3.2 Number of hours ball and bat were in conditioningenvironment.10.1.4 Test equipment used for
45、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,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 o
46、f the bat pivotsupport,10.1.8 For each impact (including 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.
47、10 Calibration certificate numbers for measurementdevices 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 b
48、aseball bats; baseballs; bat performance; BBCOR;BPF; 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 val
49、id impacts.X1.1.1 Calculate the bat-ball coefficient 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=
