1、Designation:F189009 Designation: F1890 11An American National StandardStandard Test Method forMeasuring Softball 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 o
2、f revision, 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 This test method covers a method for determining bat performance by measuring the bat-ball coe
3、fficient of restitution(BBCOR), deriving the bat performance factor (BPF) and calculating a batted ball speed (BBS). It is applicable to softball batsof any construction or material. The method provides a quantitative measure of bat dynamic performance that may be used forcomparison purposes.1.2 The
4、 BBCOR, BPF, and BBS are each calculated from measurements taken in the laboratory on test equipment meeting therequirements defined in this specification.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units
5、 that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine t
6、he applicability of regulatoryrequirements prior to use.2. Referenced Documents2.1 ASTM Standards:2F1887 Test Method for Measuring the Coefficient of Restitution (COR) of Baseballs and SoftballsF1888 Test Method for Compression-Displacement of Baseballs and SoftballsF2398 Test Method for Measuring M
7、oment of Inertia and Center of Percussion of a Baseball or Softball Bat3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 balance point, ndistance to the center of mass of a bat when measured from the distal end of the bat knob.3.1.2 bat-ball coeffcient of restitution (BBCOR), nC
8、OR of a specific ball colliding with a bat as defined in this test method.See coeffcient of restitution (COR).3.1.3 bat performance factor (BPF), nratio of BBCOR to ball COR as defined in this test method.3.1.4 center of percussion (COP), nalso known as the center of oscillation, the length of a sim
9、ple pendulum with the sameperiod as a physical pendulum, as in a bat oscillating on a pivot. Forces and impacts at this location will not induce axial reactionsat the pivot point.3.1.5 coeffcient of restitution (COR), nmeasure of impact efficiency calculated as the relative speed of the objects afte
10、r impactdivided by the relative speed of the objects before impact.3.1.6 moment of inertia (MOI), nmeasure of mass distribution relative to an axis of rotation. It is the product of the massmultiplied by the square of the distance to the mass, summed over the entire bat.4. Significance and Use4.1 Th
11、is test method offers a laboratory means to compare the performance of a softball bat.4.2 Use of this test method can provide sports governing bodies a means to compare calculated BBS and other physicalproperties of bats.5. Apparatus5.1 Test BallsOfficial softballs approved for play and tested in ac
12、cordance with the following procedures. Perform ball1This test method is under the jurisdiction of ASTM Committee F08 on Sports Equipment and Facilities and is the direct responsibility of Subcommittee F08.26 onBaseball and Softball Equipment.Current edition approved JuneNov. 1, 2009.2011. Published
13、 June 2009.November 2011. Originally approved in 1998. Last previous edition approved in 20052009 asF1890 059. DOI: 10.1520/F1890-09.10.1520/F1890-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Sta
14、ndardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possib
15、le to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
16、 Conshohocken, PA 19428-2959, United Spression test of Test Method F1888 prior to ball COR test of Test Method F1887.5.1.1 Compression350 to 375 lb at 0.25-in. deflection (1557 to 1668 N at 6.4-mm deflection) in accordance with Test MethodF1888. Balls to be labeled with compression value.5.1.2 Weigh
17、t6.25 to 6.75 oz (177.2 to 191.4 g). Balls to be labeled with weight value.5.1.3 Size12.00 to 12.25-in. (304.8 to 311.1-mm) circumference. Balls to be labeled with size value.5.1.4 Core MaterialPolyurethane.5.1.5 Ball COR0.450 to 0.470 in accordance with Test Method F1887. Balls to be labeled with C
18、OR and test speed in ft/s.5.2 Bat-Ball COR Test Apparatus :5.2.1 Ball CannonA device capable of shooting a ball at a speed of 88 ft/s. The ball shall not have a spin rate in excess of10 rpm. Typical pitching machines cannot yield the aiming accuracy required by this test method. Cannon exhaust air m
19、ust notcause motion of the bat in the absence of an impact. The ball cannon can be any distance from impact location, as long as it canmeet the ball aim requirements and provide six valid impacts in twelve shots or less.5.2.2 Bat Speed GateA light trap device, or an equivalent, capable of measuring
20、an edge traveling at speeds of between 5 and15 ft/s with a resolution of one hundredth of 1 ft/s (0.01 ft/s) with an accuracy of at least 61 % when the distance between thefirst and second sensor is between 3 in. (76.2 mm) and 3.6 in. (94.1 mm). The first sensor shall trigger when the bat rotates no
21、less than 25 and no more than 30 from its start position. It is suggested the second trigger be 3 in. (76.2 mm) away from thefirst and must not be any further than 3.6 in. (91.4 mm) away on a 6-in. (15.24-cm) radius.5.2.3 Ball Speed GateA light trap device, or an equivalent, capable of measuring a s
22、phere traveling at speeds in excess of 88ft/s (26.8 m/s) with an accuracy of 0.5 ft/s (0.2 m/s) or better. The device shall measure across a length of no less than half theball diameter to avoid centering error. For example, when testing softballs, the device shall sense an object across a 2.0-in.(5
23、0.8-mm) line. The first sensor shall trigger when the ball is no more than 12 in. (30.5 cm) from the bat surface. The second sensorshall trigger between 3.6 in. (91.4 mm) and 8 in. (203.2 mm) from the first sensor. The second sensor is located between the firstsensor and the bat surface.5.2.4 Bat Pi
24、vot SupportA turntable, rotating in the horizontal plane, with clamps to support and align the bat in the path ofthe ball. The clamp surfaces shall be a 45 Vee clamp with a radius no greater than 2.0 in. (50.8 mm). The rotating clamp and shaftassembly shall not weigh more than 6 lb (2.7 kg) and shal
25、l spin freely via ball bearings (see Fig. 1). The polar MOI for the clampturntable assembly shall not exceed 192 oz-in.2(35 117 g-cm2). The actual MOI of the clamp turntable assembly shall bedetermined and used in the performance calculations.6. Calibration and Standardization6.1 Ball Speed GateThe
26、distances between the sensors of the speed gates must be known and recorded to the stated tolerances.The accuracy of the timers used in the velocity sensors must be adequate to provide the stated velocity accuracy at maximum statedspeeds. The timers used shall be calibrated on at least a yearly basi
27、s.6.2 Reference Standards and BlanksA standard bat and ball shall be used for reference purposes to verify proper machineoperation.7. Conditioning7.1 Ball and Bat Conditioning and Test Room Conditions:7.1.1 Test balls shall be placed in an environmentally controlled space for at least 14 days immedi
28、ately before testing. Woodbats shall be stored at these environmental conditions for at least 24 h prior to testing. Non-wood bats shall be stored at theseenvironmental conditions for at least 2 h prior to testing.7.1.2 Temperature is to be maintained at 72 6 4F (22 6 2C).FIG. 1 Bat Testing MachineF
29、1890 1127.1.3 Relative humidity is to be maintained between 40 and 60 %.7.1.4 Temperature and relative humidity are to be measured and recorded hourly within 60.5F (60.3C) and 62 % RH overconditioning and test duration.8. Procedure8.1 Determination of Bat Features and Test LocationDetermine bat bala
30、nce point (BP), bat MOI, and bat COP in accordancewith Test Method F2398.8.2 Bat Test Procedure:8.2.1 Ready and calibrate ball and bat speed gates in accordance with the manufacturers instructions.8.2.2 Select a test ball in accordance with 5.1, and record the actual values of compression, weight, s
31、ize, and COR of the ballin accordance with 5.1.8.2.3 Set ball cannon to fire the ball at the desired impact speed of 88 ft/s (26.8 m/s). Valid test speeds are considered to be thosewithin 61 % of the targeted test speed.8.2.4 Mount bat in the clamps on the bat pivot support. The distal end of the ba
32、t knob must be 6 in. (152.4 mm) from the axisof rotation of the turntable assembly.8.2.5 The ball impact must be centered vertically and horizontally on the bat diameter at the previously measured COP.8.2.6 Position the bat against the start position reference, which must place the bat axis perpendi
33、cular to the ball line of travel.(See Fig. 1.)8.2.7 Verify that all speed traps are reset and ready to take data.8.2.8 Load selected test ball in ball cannon. Attempt to load test ball so that its impact with the bat will be between the stitchesof the ball.8.2.9 Shoot the ball at the bat, observing
34、the necessary safety precautions.8.2.10 Record ball inbound speed and bat rebound speed. Do not use data where the ball inbound speed deviates by more thanthe tolerances stated in 8.2.3 from the targeted test speed.8.2.11 Continue testing for six valid impact readings or for twelve total impacts. Fo
35、r a given test ball, rotate the ball in thecannon between impacts so that the impact area of the ball is different for each impact. A single test ball may be tested once oneach impact area of the ball with no rest period between impacts. Following this series of up to four impacts on a single ball,
36、arest period of at least 10 min following the last impact is required prior to retesting, using the same ball. If six valid impacts arenot achieved prior to twelve total impacts, fix the set-up to alleviate cause of invalid impacts. Verify support system for the ballcannon, ball speed gate, and bat
37、pivot support are rigid.9. Calculation of Results9.1 Calculate the BBCOR for each valid impact using Eq 1:BBCOR 5S1 1I 1 IpwR2 DSDRtdrTD 1 (1)BBCOR 5S1 1I 1 IpwR2 DSDRtdrTD 1 (1)F1890-11_1where:D = distance between bat speed sensors, in. (cm),d = distance between ball speed sensors, in. (cm),I = MOI
38、 of bat, oz-in.2(g-cm2),Ip= MOI of the pivot, oz-in.2(g-cm2),R = COP distance, in. (cm),r = radius to bat speed sensors, in. (cm),T = time for bat to travel through bat speed sensors, s,t = time for ball to travel through ball speed sensors, s, andw = weight of the ball used in each event, oz (g).9.
39、2 CalibrationDetermine the value of the combinations (D/dr) using Eq 2 as follows. Place a large calibration mass (MOI 30 000 oz-in.2) in the bat position on the pivoting stage. Measure its MOI and COPin accordance with Test Method F2398. Shoota ball of known COR and weight (w). Measure t and T. Det
40、ermine (D/dr) from ball COR as follows:Ddr51 1 Ball CORS1 1IwR2DSRtTD(2)F1890-11_29.3 Calculate the BPF for each valid impact using Eq 3:F1890-11_3F1890 1139.4 Calculate the average BPF for the test bat from the six valid impacts using Eq 4. When different balls are used to test thesame bat, always
41、be sure to calculate the BBCOR and BPF using the actual size, weight, compression, and COR of the ball usedin each of the six valid impacts:F1890-11_49.5 Calculate the BBS value of the test bat using Eq 5 and 6:F1890-11_5F1890-11_6kwhere:V = bat swing speed (mph) at the COP,v = pitch speed (mph), th
42、e horizontal speed of the ball incoming to the batter,W = bat weight, oz,wwo= weight of ball used in each event, oz (g), weight of test ball, oz (g),I = MOI of bat, oz-in.2(g-cm2),e = BPF 3 (SB COR 4 TB COR), BBCOR,a = distance from pivot to center of mass (balance point),R = COP, COP, in., andk = b
43、all-bat inertia ratio,SBCOR = 0.46, andTBCOR = the measured COR of the test ball.ball-bat inertia ratio.9.6 Calculate the average batted-ball speed (BBS) value of the test bat from the six valid impacts using Eq 7.10. Report10.1 Report the following information:10.1.1 Name of the test facility and t
44、est 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 bat conditioning and test room environments,10.1.3.2 Number of hours ball and bat were in conditioning environment.10.1.4 Test equipment used for this test method,
45、10.1.5 Test ball information in accordance with 5.1, including the compression, weight, size, and COR of the test ball,10.1.6 Bat model, length, weight tested, and any other pertinent data, such as condition of the bat or modification to the bat,10.1.7 Bat MOI and COP, and MOI of the bat pivot suppo
46、rt,10.1.8 For each impact (including invalid impacts) ball inbound speed, bat rebound speed, BBCOR, and BPF,10.1.9 Final Average Bat Performance FactorAssuming current ball COR measurement variations are 60.01, the BBCORuncertainty is currently 60.02. This results in a BPF uncertainty of 60.05. To r
47、eflect this uncertainty, the BPF assigned to eachbat will be the measured average BPF reduced by the 0.05 uncertainty. Expected future improvements in measurement equipmentand product control will reduce the above uncertainty,10.1.10 Any and all unique observations including, but not exclusively, an
48、y damage to the bat or test ball, misdirected ballimpacts, and any odd noises or vibrations, and10.1.11 Calibration certificate numbers for measurement devices and velocity timers.11. Precision and Bias11.1 Precision and bias evaluations have not been conducted for this test method. When such data a
49、re available, a precision andbias section will be added.12. Keywords12.1 bat performance; BBCOR; BBS; BPF; COR; softball bats; softballsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin 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 tec
