1、Designation: F 498 77 (Reapproved 2006)Standard Test Method forCenter Spring Constant and Spring Constant Balance ofAlpine Skis1This standard is issued under the fixed designation F 498; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of centerspring constant, forebody spring constant, and aft
3、erbody springconstant of Alpine skis. In addition, it covers a method fordetermination of the spring constant balance.1.2 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-pria
4、te safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions:2.1.1 afterbody spring constantthe load, in newtons, re-quired to deflect point A a distance of 1 cm.CA5FAfm(1)2.1.2 center spring constantthe load, in newtons, requir
5、edto deflect point M a distance of 1 cm.CM5FMfm(2)2.1.3 deflection fthe displacement of the ski under load Fmeasured at points A, B, or M normal to a line between supportpoints or the clamping plane.2.1.4 forebody spring constantthe load, in newtons, re-quired to deflect point B a distance of 1 cm.C
6、B5FBfB(3)2.1.5 load Fthe force applied normal to the support pointsor the clamping plane, at points A, B, or M. The onlycomponent of load F is shown in Fig. 1.2.1.6 point Athe support point for the afterbody of the skiwhen the center spring constant is measured or the loadapplication point when the
7、afterbody spring constant is mea-sured.2.1.7 point Bthe support point for the forebody of the skiwhen the center spring constant is measured or the loadapplication point when the forebody spring constant is mea-sured.2.1.8 point Mthe load application point when the centerspring constant is measured
8、and the clamping point when theforebody spring constant or the afterbody spring constant ismeasured. It is located at the midpoint between points A and B.2.1.9 ski size, xplthe projected length with the ski bodypressed flat against a plane surface, measured between the skitail and the ski tip, commo
9、nly referred to as chord length. Thedeveloped or material length is the length from tip to tail alongthe bottom contour of the ski.2.1.10 spring constanta measurement of the stiffness of aski in bending, expressed as a ratio of force to deflection.2.1.11 spring constant balancethe ratio of afterbody
10、spring constant divided by forebody spring constant.B 5CACB(4)3. Preparation of Apparatus3.1 Center Spring Constant EquipmentEquip supports Aand B with low-friction rolls of 2.0 6 0.1 cm diameter. Applythe load with a dynamometer or calibrate the measurement ofload with an accuracy of 60.5 N. Measur
11、e the deflection witha suitable instrument with an accuracy of 60.005 cm. Applythe load with a cylindrical contact ram having a radius of 1.06 0.1 cm and extending over the width of the ski.3.2 Forebody and Afterbody Spring Constant EquipmentProvide a clamping fixture to grip the ski as a vise with
12、a flatrigid jaw and three clamps with at least 15-cm spacing betweenthem. Locate one clamp at each end and one in the center.Clamps should be at least 3 cm wide covering the width of theski. Apply the load with a cylindrical contact ram having aradius of 1.0 6 0.1 cm and covering the width of the sk
13、i.4. Procedure (See Fig. 2)4.1 Center Spring ConstantPlace the supports at points Aand B. The location of point A is 5 6 1 cm from the tail of theski. The location of point B is a distance of C (C = xpl25cm(6 1 cm) from point A or equivalent to 20 6 1 cm from the1This test method is under the jurisd
14、iction of ASTM Committee F27 on SnowSkiing and is the direct responsibility of Subcommittee F27.30 on Skis and Boots.Current edition approved Oct. 1, 2006. Published December 2006. Originallyapproved in 1977. Last previous edition approved in 1998 as F 498 77 (1998).1Copyright ASTM International, 10
15、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.tip of the ski. Apply a load of 300 6 2 N to the ski. Readdeflection within 2 to 5 s after load application with anaccuracy of 60.05 cm.4.2 Afterbody Spring Constant and Forebody SpringConstantMount the ski to the clam
16、ping plate in a way thatthe ski forebody or ski afterbody can be bent freely from pointM. Apply a load of 50 6 0.5 N at point A or B normal to theline extended from the clamping plates. Read deflection within2 to 5 s after load application and measure it normal to theclamping plates with an accuracy
17、 of 0.05 cm.5. Report5.1 The report shall include the following:5.1.1 ASTM F 498,5.1.2 Brand, designation of model, manufacturers registra-tion number, and size of ski, and5.1.3 Results of center spring constant, forebody springconstant, afterbody spring constant, and spring constant bal-ance.6. Pre
18、cision and Bias6.1 The precision and bias of this test method is currentlybeing determined.27. Keywords7.1 Alpine skis; spring constants2Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F08-1001.FIG. 1 Physical Dimensions of Alpin
19、e Ski(a) Center Spring Constant.(b) Forebody Spring Constant.(c) Afterbody Spring Constant.FIG. 2 Loading MethodsF 498 77 (2006)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard ar
20、e 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 technical committee and must be reviewed every five years andif not
21、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 receive careful consideration at a meeting of theresponsible technical committee, which yo
22、u 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 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 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 498 77 (2006)3
