1、Designation: G203 10 (Reapproved 2016)Standard Guide forDetermining Friction Energy Dissipation in ReciprocatingTribosystems1This standard is issued under the fixed designation G203; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、the year of last 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 guide covers and is intended for use in interpretingthe friction forces recorded in reciprocating tri
3、bosystems. Theguide applies to any reciprocating tribosystem, whether it is awear or fretting test or an actual machine or device.1.2 The energy dissipation guide was developed in analyz-ing friction results in the Test Method G133 reciprocatingball-on-flat test, but it applies to other ASTM or ISO
4、recipro-cating tests. This technique is frequently used to record thefriction response in fretting tribosystems.1.3 Specimen material may play some role in the results ifthe materials under test display viscoelastic behavior. Thisguide as written is for metals, plastics, and ceramics that do notdisp
5、lay viscoelastic behavior. It also applies to lubricated andnon-lubricated contacts.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated
6、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. Referenced Documents2.1 ASTM Standards:2G40 Terminology Relating to Wear and ErosionG115 Guide for Measu
7、ring and Reporting Friction Coeffi-cientsG133 Test Method for Linearly Reciprocating Ball-on-FlatSliding WearG163 Guide for Digital Data Acquisition in Wear andFriction Measurements3. Terminology3.1 Definitions:3.1.1 coeffcient of friction, nin tribology, the dimension-less ratio of the friction for
8、ce (F) between two bodies to thenormal force (N) pressing these bodies together. G403.1.2 frettingsmall amplitude oscillatory motion, usuallytangential between two solid surfaces in contact. G403.2 Definitions of Terms Specific to This Standard:3.2.1 friction envelopewhen making friction energy loss
9、measurements, the graphic representation of the cyclic frictionforce versus time history of a tribosystem in which theboundaries surrounding these variations in time produces ashape with a measurable area.3.2.2 reciprocating tribosystemsliding system where thedirection of motion of the moving member
10、 periodically re-verses (for example, piston in a cylinder).3.3 Acronyms:3.3.1 DAS, ndata acquisition system.3.3.2 FED, nfriction energy dissipated. The work requiredto overcome the resistance to motion encountered in slidingone solid on another expressed in energy units (joules).3.3.3 RFED, nrelati
11、ve friction energy dissipated. Thework required to overcome the resistance to motion encoun-tered in sliding one solid on another solid expressed in arbitraryunits for comparison studies on candidate tribocouples.4. Summary of Guide4.1 Frictional effects can be a concern in many tribosystemsso it is
12、 common to monitor friction force in laboratory tests andeven field evaluations of machines. There are many ways ofreporting the recorded friction forces: friction force (see GuideG115), average friction force for a test, average coefficient offriction, static and kinetic coefficient of friction, co
13、efficient offriction at periodic time intervals, etc. This guide presents amethodology to convert friction forces monitored throughout atest cycle into a test metric called friction energy dissipated(FED). For within-lab tests the metric is relative friction energy1This guide is under the jurisdicti
14、on of ASTM Committee G02 on Wear andErosion and is the direct responsibility of Subcommittee G02.50 on Friction.Current edition approved July 1, 2016. Published July 2016. Originally approvedin 2010. Last previous edition approved in 2010 as G203 10. DOI:10.1520/G020310R16.2For referenced ASTM stand
15、ards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
16、 19428-2959. United States1dissipated (RFED). Both of these terms represent an integra-tion of the area within the force/tangential displacement outputof the force measurement system.4.2 The FED parameter will have energy units; the RFEDparameter can have arbitrary units because it is used tocompare
17、 various candidates in the same test in the samelaboratory using the same test equipment.5. Significance and Use5.1 Many sliding systems exhibit intermittent high frictionforce excursions compared to competing tribosystems.However, where friction forces or friction coefficients areaveraged, the test
18、 data may show that the two systems have thesame friction characteristics, when in fact they were not thesame; there was a friction “problem” in the one with theperiodic aberrations. The FED takes into account all frictionforces that occur in the test increment. It is all of the frictionenergy that
19、the couple dissipated in the designated test dura-tion. It captures the friction profile of a system in a singlenumber that can be used to screen candidate couples forfriction characteristics.5.2 If the friction energy used in a reciprocating tribosystemis of concern this metric along with the frict
20、ion recording,average coefficient of friction, and standard deviation of theforce readings, produces the most meaningful data. It is ametric of the energy loss in a tribosystem.6. Apparatus6.1 This guide can be used with any reciprocating wear testor device that is instrumented to produce a friction
21、 forcerecording for the entire test interval with a force recording atintervals that allow characterization of each reciprocating(forward and back) cycle. A chart recorder produces adaptableforce information and any data logging system that allowsintegration of the area of a force/distance recording
22、 for a testcan be used (see Guide G163). Fig. 13is an example of suitableexperimental data from a single back and forth cycle. Thefigure shows force as the vertical axis and sliding distance asthe horizontal axis in a fretting test. Fig. 2 is the force/distancerecording from Test Method G133 sphere-
23、on-flat test modifiedto produce four hours of rubbing using Option B (see 8.1.2).The ability to record friction forces depends on the samplingrate of the DAS. Thus, when using friction energy dissipationas a test metric, all tests used in ranking tribosystems shoulduse the same force measurement sys
24、tem, force sampling rate,DAS and energy analysis technique.7. Test Specimen Configuration7.1 This friction assessment methodology has been used onreciprocating sphere-on-flat, block-on-ring, and flat-on-flatspecimens.8. Procedure8.1 Two options are described, depending on the type offriction-measuri
25、ng and recording system available for use. InOption A, discrete friction loop capture, the features ofindividual cycles are recorded by a high-speed DAS (forexample, see Fig. 1). In Option B, details of individual cyclesare not clearly observable, but rather, the general trend of thecyclic friction
26、force variation, called a friction envelope, isobtained.8.1.1 Option A, Cumulative Friction Loop MethodTheDAS shall have sufficiently high recording rate and frictionforce resolution to enable the details of friction versus timeplots for individual forward and back cycles, called frictionloops, to b
27、e captured. It is the responsibility of the user toensure the proper calibration of the force and displacementsensors. The area enclosed by each loop, in force-time space, isa measure of the frictional energy dissipated during that loop.Cumulative summation of the areas of all loops generatedduring
28、a given test represents the total FED. A variation of thefriction loop method is when time, rather than displacement ismeasured during reciprocating motion.An example is shown inFig. 2. In that case, the time axis is converted to slidingdistance, using the known velocity characteristics of thetribos
29、ystem, and the areas enclosed by the friction force traceand the horizontal axis are summed to provide the FED.8.1.2 Option B, Friction Envelope MethodThis methodprovides a relative measure of the frictional energy dissipatedand is useful for within-laboratory comparisons. It can utilizelower speed
30、DAS or chart recorders where the details ofindividual loops cannot be resolved. In that case, the shapeproduced by the friction force versus sliding distance or timerecord is enclosed and measured (see Fig. 3). These enclosingshapes can be called friction envelopes. If the velocity charac-teristics
31、of the tribosystem do not change during the test, thenthe time can be used as one axis of the friction envelope plot.Comparing the areas enclosed by friction envelopes, plottedusing the same axes scales, provides a measure of the RFED.NOTE 1Option A versus Option BFig. 4 represents the frictionenvel
32、ope produced by enclosing the detailed friction force versus elapsedtime trace shown in Fig. 2. It is clear that by enclosing the plot, thefrictional energy of the spaces between loops included in the tally.Therefore, the use of Option B should not be assumed to provide anaccurate measure of the fri
33、ctional energy dissipated by individual recip-rocating cycles, but rather it can be used as a convenient way ofcomparing the frictional behavior of various material combinations undersimilar test conditions.9. Report9.1 Information on the FED may be included as a supple-ment to the report that descr
34、ibes the testing parameters,specimen preparation, cleaning methods, materials, and otheraspects associated with selected friction test method to whichthese data apply. Examples of supplementary information onFED, reported in the form of Option B, are given in Fig. 5.10. Keywords10.1 friction; fricti
35、on coefficient; friction energy3Mohrbacher, H., et al, “The Influence of Humidity on the Behavior of PVD TiNCoatings,” Wear, Vol 180, 1995, pp. 43-52.G203 10 (2016)2FIG. 1 Tangential Force-Displacement Hysteresis Loops between Measured during Fretting between TiN (Sample B) and Corundum in(a)Moist(R
36、H10%)AirG203 10 (2016)3FIG. 2 Areas Under the Traces of Individual StrokesNOTE 1Area can be measured by counting squares, inputting the shapes into a CAD analysis program, etc.FIG. 3 Strip Chart Recordings from Test Method G133 Used in RFED DeterminationG203 10 (2016)4FIG. 4 Area Enclosed by the Tot
37、al Friction EnvelopeG203 10 (2016)5APPENDIXES(Nonmandatory Information)X1. FRETTING LOOPSX1.1 Fretting tribosytems usually produce significantchanges in friction forces as testing cycles increased. If data islogged in detail for each fretting cycle (for example, 100readings per test cycle) the FED c
38、an be presented in 3D formatwith time (number of cycles) as the third axis as shown in Fig.X1.1. The volume enclosed on the shape can be an RFEDparameter.FIG. 5 Typical RFED ReportG203 10 (2016)6X2. DEALING WITH SHORT-LIVED FRICTION ABERRATIONSX2.1 Some tribosystems produce instantaneous force spike
39、sthat are significant but may not significantly increase the areain an RFED evaluation. This is the reason why this guiderecommends including the force recording in the test report.The force aberrations will be evident. Inclusion of the standarddeviation of the force recording is another tool that c
40、an be usedto quantify these friction results (Fig. X2.1).FIG. X1.1 “Friction Energy Volume” from a Fretting TestFIG. X2.1 Use of Standard Deviation to Deal with Short-Lived Friction Force ExcursionsG203 10 (2016)7ASTM International takes no position respecting the validity of any patent rights asser
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44、ational, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 10 (2016)8
