1、Designation: F2844 11Standard 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 force of softball andbaseball bat
3、 barrels as defined by a static compression displace-ment test.1.2 This standard is not intended to define the performanceof softball or baseball bats but to determine the intrinsic barrelcompression of a specific bat.1.3 This standard can be used to compare the relative barrelcompression force of b
4、ats using a relatively slow, non-impactloading rate.1.4 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 onlyand are not considered standard.1.5 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific
6、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 loadhead during the test.2.1.3 bat taper, nsection of the bat where the barreldiameter begins to decrease to join the handle of a muchsma
7、ller 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 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
8、.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 bats.4. Apparatus4.1 Compression Device, to compress the test bat betweentwo rigid cylindrical shapes to at most 0.070 in. (1.78 mm)
9、netdisplacement. 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 suffic
10、ient sothat the force shall be applied through the centerline of thebarrel diameter and load cylinders. A means of centering thetest bat is required so that the axis of the bat barrel isperpendicular (62) with the cylindrical platens. The deviceshould provide the ability to control the force to 1 lb
11、 (4.5 N)and deflection to 0.001 in. (0.025 mm).4.2 Load HeadsA pair of cylindrical shapes with a radiusof curvature of 1.93 6 0.050 in. (49 6 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 ce
12、nterlines within 60.010 in. (60.25 mm), theircylindrical axis parallel within 61 and their curved surfacesin direct opposition to each other.4.3 Load Cell, to measure the compressive load up to atleast 1000 lb (4459 N) with a resolution of at least 1 lb (4 N).4.4 Displacement Gauge, with a range of
13、at least 1.0 in.(25.4 mm) and a resolution of no less than 0.001 in. (0.025mm).4.5 Calibration CylinderA 2.25-in. (57-mm) diameterhollow metal cylinder with a barrel compression between 200and 300 lb. The cylinders calibrated compression and calibra-tion date shall be marked on the cylinder. The str
14、ength of thecylinder shall be sufficient not to permanently yield under a0.07-in. (1.78-mm) displacement when tested in accordancewith this standard.1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F0
15、8.26 onBaseball and Softball Equipment.Current edition approved April 1, 2011. Published May 2011. Originallyapproved in 2010. Last previous edition approved in 2010 as F2844 10. DOI:10.1520/F2844-11.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
16、 United States.5. Calibration and Standardization5.1 Test the calibration cylinder following this standardbefore each test session. If the compression of the calibrationcylinder differs by more than 620 lb (689 N) from itscalibrated value, recalibrate the load cell or displacementgauge, or both, per
17、 the manufacturers instructions.5.2 Calibrate the load cell, displacement gauge, and thecalibration cylinder at least annually to a NIST traceablestandard.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 c
18、ompression press so that thelongitudinal axis of the bat is perpendicular (62) to thecylindrical platens and the cap end of the bat is 6 6 0.25 in.(152 6 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 t
19、he bat from moving axially duringload application.7.2 Set the load cell gauge to zero.7.3 Activate the compression press until the cylindrical loadheads are in contact with the bat with 10 6 5lb(446 22 N)pre-load applied to the bat.7.4 Set the load cell gauge and displacement gauge to zero.7.5 Compr
20、ess the bat at a rate which is sufficient tocomplete the deflection in 10 to 20 s.7.5.1 Softball bats shall have an initial displacement of0.020 6 0.001 in. (0.51 6 0.025 mm).7.5.2 Baseball bats shall have an initial displacement of0.010 6 0.001 in. (0.25 6 0.025 mm).7.6 Set the load cell gauge and
21、displacement gauge to zero.7.7 Compress the bat at a rate which is sufficient tocomplete the deflection in 10 to 20 s.7.7.1 Softball bats shall have a displacement of 0.050 60.001 in. (1.3 6 0.025 mm).7.7.2 Baseball bats shall have a displacement of 0.030 60.001 in. (0.76 6 0.025 mm).7.7.3 Record th
22、e peak load and corresponding displacement.7.8 Release the applied load.7.9 Repeat the steps in 7.1-7.8 at +45, 45, and 90 fromthe test first orientation.7.10 The bat may be tested at locations other than the 6 in.(152 mm) location, provided the alternate location is at least 2in. (51 mm) from the e
23、nd 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:BC = barrel compression (lb or N)Fu= Compression force from the loading at
24、 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, and any other pertinentdata such as condition of the bat or modifications
25、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; andFIG. 1 Test ApparatusF2844 1129.1.5 Calibration certificate numbers for measurement de-vices.10. Precision and Bias10.1 Precis
26、ion 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 International takes no position respecting the validity of any patent rights asse
27、rted 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
28、 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 should be addressed to ASTM International Headquarters. Your comments will recei
29、ve 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 Standards, at the address shown below.This standard is copyrighted by ASTM Inter
30、national, 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 serviceastm.org (e-mail); or throug
31、h 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 113
