1、Designation: F2844 10Standard Test Method forDisplacement Compression of Softball and Baseball BatBarrels1This standard is issued under the fixed designation F2844; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. 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 describes a comparative measurementmethod for determining the compression of softball andbaseball bat barre
3、ls as defined by a static compression displace-ment test.1.2 This standard can be used to compare the relative barrelcompression of bats using a relatively slow, non-impact,loading rate.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathe
4、maticalconversions to SI units that are provided for information 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 hea
5、lth practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 barrel compression, nthe force reading to deflect thebat barrel by the specified distance.2.1.2 barrel deflection, nthe displacement of the loa
6、dhead during the test.2.1.3 bat taper, nsection of the bat where the barreldiameter begins to decrease to join the handle of a muchsmaller diameter.2.1.4 force, nthe amount of resistance applied perpen-dicular to the surface of a bat barrel to cause the barrel todisplace.2.1.5 non-solid bat, na bat
7、of hollow construction.2.1.5.1 DiscussionBat may be filled with inserts or flex-ible materials and still be considered a non-solid bat.3. Significance and Use3.1 This test method offers a means to compare the barrelcompression of softball and baseball bats. This test is notintended for wood or solid
8、 bats.3.2 This standard is not intended to define performance ofsoftball or baseball bats but to determine the intrinsic barrelcompression of a specific bat.4. Apparatus4.1 Compression Device, to compress the test bat betweentwo rigid cylindrical shapes to at most 0.070 in. (1.78 mm) netdisplacement
9、. The device shall allow testing at any point alongthe barrel, to within 2 in. of the end cap. The compressiondevice must be able to produce a load of at least 1000 lb (4459N). The load heads shall be able to open more than 2.75 in.(69.9 mm). The width of the device needs to be sufficient sothat for
10、ce shall be applied through the centerline of the barreldiameter and load cylinders. A means of centering the test batis required so that the axis of the bat barrel is perpendicular(62) with the cylindrical platens. The device should providethe ability to control the force to 1 lb (4.5 N) and deflec
11、tion to0.001 in. (0.013 mm).4.2 Load HeadsA pair of cylindrical shapes with a radiusof curvature of 1.93 + 0.050 in. (49 + 1.3 mm) over a chordheight of at least 0.20 in. (5 mm) (as shown in Fig. 1) made ofsteel or a material of equivalent stiffness. The heads are setwith their centerlines within +0
12、.010 in., their cylindrical axisparallel within +1 and their curved surfaces in direct opposi-tion to each other.4.3 Load Cell, to measure the compressive load up to atleast 1000 pounds (4459 N) with a resolution of 1 lb (4 N).4.4 Displacement Gauge, with a range of at least 1.0 in.(25.4 mm) and a r
13、esolution no less than 0.001 in. (0.025 mm).4.5 Calibration CylinderA 2.25-in. diameter hollowmetal cylinder with a barrel compression between 200 and 300lb. The cylinders calibrated compression and calibration dateshall be marked on the cylinder. The strength of the cylindershall be sufficient not
14、to permanently yield under a 0.07 in.displacement when tested in accordance with this standard.1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.26 onBaseball and Softball Equipment.Current edition
15、 approved May 1, 2010. Published July 2010. DOI: 10.1520/F2844-10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Calibration and Standardization5.1 Test the calibration cylinder following this standardbefore each test session. If
16、 the compression of the calibrationcylinder differs by more than +20 lb from its calibrated value,recalibrate the load cell or displacement gauge, or both, per themanufacturers instructions.5.2 Calibrate the load cell, displacement gauge, and thecalibration cylinder at least annually to a NIST trace
17、ablestandard.6. Conditioning6.1 Test unit shall be within operating limits of the forcegauge and deflection gauges used.7. Procedure7.1 Place the bat in the compression press so that thelongitudinal axis of the bat is perpendicular (+2) to thecylindrical platens and the cap end of the bat is 6 + 0.2
18、5 in.(152 + 6 mm) from the centerline of the cylindrical platens.When testing bats with tapered barrels, a stop at the end of thebarrel is needed to prevent the bat from moving axially duringload application.7.2 Activate the compression press until the cylindrical loadheads are in contact with the b
19、at with 15+1lb(67+4.5N)pre-load applied to the bat.7.3 Compress the bat at a rate which is sufficient tocomplete the deflection in 10 to 20 s.7.3.1 Softball bats shall have an initial displacement of0.020 + 0.001 in. (0.51+ 0.025 mm).7.3.2 Baseball bats shall have a initial displacement of 0.010+ 0.
20、001 in. (0.25 + 0.025 mm).7.4 Set the load cell gage to zero.7.5 Compress the bat at a rate which is sufficient tocomplete the deflection in 10 to 20 s. Record both the peakforce and deflection.7.5.1 Softball bats shall have a displacement of 0.050 +0.001 in. (1.3 + 0.025 mm).7.5.2 Baseball bats sha
21、ll have a displacement of 0.030 +0.001 in. (0.76 + 0.025 mm).7.5.3 Record load when specified displacement is reached.7.6 Release the applied load. Repeat the steps in 7.1-7.7 at+45, 45, and 90 from the test first orientation.7.7 The bat may be tested at locations other than the the 6 in.(152 mm) lo
22、cation, provided the alternate location is at least 2in. (51 mm) from the end cap and taper. In these cases, thebarrel compression location should be noted (L in Fig. 1).8. Calculation8.1 Barrel Compression (BC) is calculated from the averageof the four readings as:BC 514F01 F1451 F451 F90! (1)where
23、:BC = barrel compression (lb or N)Fu= Compression force from the loading at the angle u (lbor N)9. Report9.1 Report the following information:9.1.1 Name of the test facility and test operator;9.1.2 Test date;9.1.3 Test equipment used for this test method, including:9.1.3.1 Bat model, length, weight,
24、 and any other pertinentdata such as condition of the bat or modifications to the bat,and9.1.3.2 Each bat barrel compression and deflection readingas shown in Table 1;9.1.4 Any important observations; for example, damage tothe bat or any noises; and9.1.5 Calibration certificate numbers for measureme
25、nt de-vices.FIG. 1 Test ApparatusF2844 10210. Precision and Bias10.1 Precision and bias evaluations have not been con-ducted for this test method. When such data are available, aprecision and bias section will be added.11. Keywords11.1 ball bat; compression-displacement; compression forceASTM Intern
26、ational 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 t
27、heir own responsibility.This standard is subject to revision at any time by the responsible technical committee and 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 shoul
28、d be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of 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 Stand
29、ards, 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 610-8
30、32-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Compression and Deflection ReadingsAngle Compression Force(lb or N)Deflection(in. or mm)Location from end of Barrel(in. or mm)0+454590Avg.F2844 103
