ASTM G203-10

Standard Guide for Determining Friction Energy Dissipation in Reciprocating Tribosystems

SIGNIFICANCE AND USE
Many sliding systems exhibit intermittent high friction force excursions compared to competing tribosystems. However, where friction forces or friction coefficients are averaged, the test data may show that the two systems have the same friction characteristics, when in fact they were not the same; there was a friction “problem” in the one with the periodic aberrations. The FED takes into account all friction forces that occur in the test increment. It is all of the friction energy that the couple dissipated in the designated test duration. It captures the friction profile of a system in a single number that can be used to screen candidate couples for friction characteristics.
If the friction energy used in a reciprocating tribosystem is of concern this metric along with the friction recording, average coefficient of friction, and standard deviation of the force readings, produces the most meaningful data. It is a metric of the energy loss in a tribosystem.
SCOPE
1.1 This guide covers and is intended for use in interpreting the friction forces recorded in reciprocating tribosystems. The guide applies to any reciprocating tribosystem, whether it is a wear or fretting test or an actual machine or device.
1.2 The energy dissipation guide was developed in analyzing friction results in the Test Method G133 reciprocating ball-on-flat test, but it applies to other ASTM or ISO reciprocating tests. This technique is frequently used to record the friction response in fretting tribosystems.
1.3 Specimen material may play some role in the results if the materials under test display viscoelastic behavior. This guide as written is for metals, plastics, and ceramics that do not display viscoelastic behavior. It also applies to lubricated and non-lubricated contacts.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2010
• ICS: 21.260 - Lubrication systems
• Technical Committee: G02 - Wear and Erosion
• Drafting Committee: G02.50 - Friction

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G203 − 10
StandardGuide for
Determining Friction Energy Dissipation in Reciprocating
Tribosystems
This standard is issued under the fixed designation G203; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This guide covers and is intended for use in interpreting 3.1 Definitions:
the friction forces recorded in reciprocating tribosystems. The
3.1.1 coeffıcient of friction, n—in tribology, the dimension-
guide applies to any reciprocating tribosystem, whether it is a
less ratio of the friction force (F) between two bodies to the
wear or fretting test or an actual machine or device. G40
normal force (N) pressing these bodies together.
1.2 The energy dissipation guide was developed in analyz-
3.1.2 fretting—small amplitude oscillatory motion, usually
ing friction results in the Test Method G133 reciprocating tangential between two solid surfaces in contact. G40
ball-on-flat test, but it applies to other ASTM or ISO recipro-
3.2 Definitions of Terms Specific to This Standard:
cating tests. This technique is frequently used to record the
3.2.1 friction envelope—when making friction energy loss
friction response in fretting tribosystems.
measurements, the graphic representation of the cyclic friction
1.3 Specimen material may play some role in the results if
force versus time history of a tribosystem in which the
the materials under test display viscoelastic behavior. This
boundaries surrounding these variations in time produces a
guide as written is for metals, plastics, and ceramics that do not shape with a measurable area.
display viscoelastic behavior. It also applies to lubricated and
3.2.2 reciprocating tribosystem—sliding system where the
non-lubricated contacts.
direction of motion of the moving member periodically re-
1.4 The values stated in SI units are to be regarded as
verses (for example, piston in a cylinder).
standard. No other units of measurement are included in this
3.3 Acronyms:
standard.
3.3.1 DAS, n—data acquisition system.
1.5 This standard does not purport to address all of the
3.3.2 FED, n—frictionenergydissipated.Theworkrequired
safety concerns, if any, associated with its use. It is the
to overcome the resistance to motion encountered in sliding
responsibility of the user of this standard to establish appro-
one solid on another expressed in energy units (joules).
priate safety and health practices and determine the applica-
3.3.3 RFED, n—relative friction energy dissipated. The
bility of regulatory limitations prior to use.
work required to overcome the resistance to motion encoun-
2. Referenced Documents teredinslidingonesolidonanothersolidexpressedinarbitrary
units for comparison studies on candidate tribocouples.
2.1 ASTM Standards:
G40 Terminology Relating to Wear and Erosion
4. Summary of Guide
G115 Guide for Measuring and Reporting Friction Coeffi-
cients
4.1 Frictional effects can be a concern in many tribosystems
G133 Test Method for Linearly Reciprocating Ball-on-Flat
soitiscommontomonitorfrictionforceinlaboratorytestsand
Sliding Wear
even field evaluations of machines. There are many ways of
G163 Guide for Digital Data Acquisition in Wear and
reporting the recorded friction forces: friction force (see Guide
Friction Measurements
G115), average friction force for a test, average coefficient of
friction, static and kinetic coefficient of friction, coefficient of
friction at periodic time intervals, etc. This guide presents a
This guide is under the jurisdiction of ASTM Committee G02 on Wear and
methodology to convert friction forces monitored throughout a
Erosion and is the direct responsibility of Subcommittee G02.50 on Friction.
test cycle into a test metric called friction energy dissipated
Current edition approved April 1, 2010. Published May 2010. DOI:10.1520/
G0203–10.
(FED).Forwithin-labteststhemetricis relative friction energy
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dissipated (RFED). Both of these terms represent an integra-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
tion of the area within the force/tangential displacement output
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of the force measurement system.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G203 − 10
4.2 The FED parameter will have energy units; the RFED Option A, discrete friction loop capture, the features of
parameter can have arbitrary units because it is used to individual cycles are recorded by a high-speed DAS (for
compare various candidates in the same test in the same
example, see Fig. 1). In Option B, details of individual cycles
laboratory using the same test equipment.
are not clearly observable, but rather, the general trend of the
cyclic friction force variation, called a friction envelope, is
5. Significance and Use
obtained.
5.1 Many sliding systems exhibit intermittent high friction
8.1.1 Option A, Cumulative Friction Loop Method—The
force excursions compared to competing tribosystems.
DAS shall have sufficiently high recording rate and friction
However, where friction forces or friction coefficients are
force resolution to enable the details of friction versus time
averaged, the test data may show that the two systems have the
plots for individual forward and back cycles, called friction
same friction characteristics, when in fact they were not the
loops, to be captured. It is the responsibility of the user to
same; there was a friction “problem” in the one with the
ensure the proper calibration of the force and displacement
periodic aberrations. The FED takes into account all friction
sensors.The area enclosed by each loop, in force-time space, is
forces that occur in the test increment. It is all of the friction
a measure of the frictional energy dissipated during that loop.
energy that the couple dissipated in the designated test dura-
Cumulative summation of the areas of all loops generated
tion. It captures the friction profile of a system in a single
during a given test represents the total FED.Avariation of the
number that can be used to screen candidate couples for
friction loop method is when time, rather than displacement is
friction characteristics.
measuredduringreciprocatingmotion.Anexampleisshownin
5.2 If the friction energy used in a reciprocating tribosystem
Fig. 2. In that case, the time axis is converted to sliding
is of concern this metric along with the friction recording,
distance, u
...