ASTM F498-77(2006)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F498–77 (Reapproved 2006)
Standard Test Method for
Center Spring Constant and Spring Constant Balance of
Alpine Skis
ThisstandardisissuedunderthefixeddesignationF498;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.1.6 point A—the support point for the afterbody of the ski
when the center spring constant is measured or the load
1.1 This test method covers the determination of center
application point when the afterbody spring constant is mea-
springconstant,forebodyspringconstant,andafterbodyspring
sured.
constant of Alpine skis. In addition, it covers a method for
2.1.7 point B—the support point for the forebody of the ski
determination of the spring constant balance.
when the center spring constant is measured or the load
1.2 This standard does not purport to address all of the
application point when the forebody spring constant is mea-
safety concerns, if any, associated with its use. It is the
sured.
responsibility of the user of this standard to establish appro-
2.1.8 point M—the load application point when the center
priate safety and health practices and determine the applica-
spring constant is measured and the clamping point when the
bility of regulatory limitations prior to use.
forebody spring constant or the afterbody spring constant is
2. Terminology measured.Itislocatedatthemidpointbetweenpoints Aand B.
2.1.9 ski size, x —the projected length with the ski body
2.1 Definitions: pl
pressed flat against a plane surface, measured between the ski
2.1.1 afterbody spring constant—the load, in newtons, re-
tail and the ski tip, commonly referred to as chord length. The
quired to deflect point A a distance of 1 cm.
developed or material length is the length from tip to tail along
F
A
C 5 (1) the bottom contour of the ski.
A
f
m
2.1.10 spring constant—a measurement of the stiffness of a
2.1.2 center spring constant—theload,innewtons,required
ski in bending, expressed as a ratio of force to deflection.
to deflect point M a distance of 1 cm.
2.1.11 spring constant balance—the ratio of afterbody
F spring constant divided by forebody spring constant.
M
C 5 (2)
M
f
m
C
A
B 5 (4)
2.1.3 deflection f—the displacement of the ski under load F C
B
measuredatpoints A, B,or Mnormaltoalinebetweensupport
3. Preparation of Apparatus
points or the clamping plane.
2.1.4 forebody spring constant—the load, in newtons, re- 3.1 Center Spring Constant Equipment—Equip supports A
quired to deflect point B a distance of 1 cm. and B with low-friction rolls of 2.0 6 0.1 cm diameter.Apply
the load with a dynamometer or calibrate the measurement of
F
B
C 5 (3)
B load with an accuracy of 60.5 N. Measure the deflection with
f
B
a suitable instrument with an accuracy of 60.005 cm. Apply
2.1.5 load F—theforceappliednormaltothesupportpoints
the load with a cylindrical contact ram having a radius of 1.0
or the clamping plane, at points A, B, or M. The only
6 0.1 cm and extending over the width of the ski.
component of load F is shown in Fig. 1.
3.2 Forebody and Afterbody Spring Constant Equipment—
Provide a clamping fixture to grip the ski as a vise with a flat
rigidjawandthreeclampswithatleast15-cmspacingbetween
This test method is under the jurisdiction of ASTM Committee F27 on Snow
them. Locate one clamp at each end and one in the center.
Skiing and is th
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