1、Designation: F1722 09F1722 15Standard Test Method forDetermining Mass and Moment of Inertia of Alpine Skis1This standard is issued under the fixed designation F1722; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、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 test measurement methods for mass and moment of inertia of adult Alpine skis.21.2 No limitation to
3、ski size is proposed. This test method is applicable to all adult Alpine skis.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated wit
4、h its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3F472 Terminology for Geometry of Alpine Skis2.2 ISO Standards:4ISO 554
5、 Standard Atmospheres for Conditioning and/or TestingSpecificationsISO 6003 Alpine SkisDetermination of Mass and Polar Moment of InertiaLaboratory Measurement Method3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 mass of ski, mthe mass of a finished, manufactured ski without a
6、ny mounted parts, expressed in kilograms.3.1.2 moment of inertia, Ithe mass moment of inertia of the ski about its center of gravity, expressed in kilogram-metressquared.4. Significance and Use4.1 This test method provides a means for determining the mass and moment of inertia of adult Alpine skis.
7、It is not intendedto evaluate data with regard to the quality of the ski.5. Apparatus5.1 Weighing Device, accurate to 60.02 kg.5.2 Fulcrum, for locating the center of gravity of the ski.5.3 Time Measurement Device (stopwatch), accurate to at least 0.1 s.5.4 Measuring Device, in accordance with Fig.
8、1, consisting of the following parts:5.4.1 Clamping Device, A, consisting of two clamping fixtures. The top clamping fixture has a hole with a mark to locate thecenter of gravity and two additional holes at a distance, df, from the center mark for fixation of the filaments, B. The recommendeddimensi
9、on for df is 2575 mm, and the mass of the clamping device shall be less than 0.1 kg.1 This test method is under the jurisdiction of ASTM Committee F27 on Snow Skiing and is the direct responsibility of Subcommittee F27.30 on SkisSkiing andBootsSnowboarding Equipment.Current edition approved June 1,
10、2009July 1, 2015. Published July 2009August 2015. Originally approved in 1996. Last previous edition approved in 20032009 asF1722 96 (2003).F1722 09. DOI: 10.1520/F1722-09.10.1520/F1722-15.2 This test method is meant to conform in all significant aspects to the test method for determining mass and p
11、olar moment of inertia of Alpine skis as set forth in ISO6003.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website
12、.4 Available from American National Standards Institute, 11 W. 42nd St., 13th Floor, New York, NY 10036.This 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 techni
13、cally possible 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 Bo
14、x C700, West Conshohocken, PA 19428-2959. United States15.4.2 Top Plate, C, with two holes separated by the distance 2df for the fixation of filaments, B. The plate, C, shall be fixed ona stiff, horizontal beam.5.4.3 Two Filaments, B, with equal lengths, l, that connect the top plate with the clampi
15、ng device. The ratio df:l shall beapproximately 1:40. With the recommended dimension df = 25 = 75 mm, and the length, l = 1000 mm. The filaments shall bemade of materials with low elongation and high strength (for example, tennis racket string and fishing line). The diameter of thefilaments shall be
16、 not more than 1.0 mm.6. Sampling and Conditioning6.1 In order to ensure comparability, it is recommended that one of the following ski sizes be used if the data measured are tobe published: 150, 165, or 185 cm. The ski size, measured by chord length (see Terminology F472 for the definition of chord
17、length), should be within 3 cm of the value chosen. From these three sizes, choose the one that is most representative of the testedmodel.6.2 All measurements shall be taken from a finished, manufactured ski without any mounted parts.6.3 All measurements shall be taken from a ski that has been condi
18、tioned in a standard atmosphere 20/65 (ISO 554) (that is,the ski shall be placed in this atmosphere for at least 24 h prior to measurements being taken).7. Calibration of Measuring Device7.1 Differences in construction between the different measuring devices can lead to different measurement results
19、, which deviatefrom the theoretical value of the polar moment of inertia. In order to reduce such deviations, it is recommended that a testequipment validation factor, c, be determined for each measuring device.FIG. 1 Measuring DeviceF1722 1527.2 The test equipment validation factor is determined fr
20、om the ratio of the calculated moment of inertia to the measuredmoment of inertia of a bar of steel with dimensions 1 to 8 by 20 to 30 by 1200 to 1700 mm. To ensure accurate measurements,it is important that the steel bar be level when placed in the test device. Any vertical displacement of the stee
21、l bar may altercalculation of the test device evaluation factor.7.3 The theoretical moment of inertia, Ith, is calculated from the following formula:Ith5ma21b2!12 (1)where:a = length of the bar, m,b = width of the bar, m, andm = mass of the bar, kg.7.4 Using this theoretical value and the measured v
22、alue, the test equipment validation factor, c, can be determined from thefollowing formula:c 5IthI (2)where:Ith = theoretical polar moment of inertia, andI = measured polar moment of inertia.7.5 The test equipment validation factor, c, should fall within a range from 0.9 to 1.1. If c lies outside th
23、is range, the testequipment shall be checked and brought into conformity with this test method.8. Procedure8.1 Measure the mass of the ski with the weighing device (5.1).8.2 Place the ski on the fulcrum (5.2) until it balances, to determine the center of gravity. Mark the center of gravity on the sk
24、isurface.8.3 Mount the ski in the clamping device, A, (5.4.1) in such a way that the center of gravity mark is in the center of the holein the top clamping fixture midway between the two filaments. The longitudinal center axis shall be perpendicular to a line drawnbetween the two filaments, B (see F
25、ig. 1).8.4 Let the ski come to rest suspended in the device. Eliminate any swinging motion. It is important that the test area be freeof air movement, as this affects test accuracy.8.5 With the hand, rotate the ski horizontally about its axis of gravity. Lateral displacement of the center of gravity
26、 exceeding10 mm shall be avoided. The twist angle should be approximately 25.8.6 After displacing the ski, release it to swing freely around the perpendicular axis through the center of gravity. The timerequired for the ski to complete at least five cycles is recorded with the stopwatch (5.3). The t
27、ime for one oscillation, T, isdetermined by the following formula:T 5recorded timen (3)where:n = number of cycles recorded.9. Expression of Results9.1 Mass of the SkiExpress the mass of the ski, m, in kilograms.9.2 Moment of Inertia of the SkiExpress the moment of inertia of the ski, I, in kilogram-
28、metres squared, using the followingformula:I 5S T2 D2mg df2l (4)where:T = period of oscillation, s,m = mass of the finished manufactured ski without any ancillary parts, kg,g = acceleration due to gravity, m/s2,df = half-distance between the filaments measured on the top plate, m, andF1722 153l = le
29、ngth of the filaments, m.10. Tolerances10.1 Measurement Tolerances:Mass 0.02 kgMoment of inertia 0.02 kg-m210.2 Tolerances on Published DataIf data are published by the manufacturer with reference to this test method, the followingtolerances shall be observed:Mass 10 %Moment of inertia 10 %11. Repor
30、t11.1 Report the following information:11.1.1 Reference to this test method,11.1.2 Name of ski manufacturer,11.1.3 Model designation of ski,11.1.4 Nominal length of ski,11.1.5 Registration number of ski, and11.1.6 Any deviation from this test method, with an explanation of the reason for the deviati
31、on.12. Precision and Bias12.1 PrecisionThe precision of this test method is currently being determined.12.2 BiasThere should be no bias in measurement of mass if the specification in 5.1 is followed. Bias in measurement of themoment of inertia is controlled by the test equipment evaluation factor de
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