1、Designation: E468 11E468 18Standard Practice forPresentation of Constant Amplitude Fatigue Test Results forMetallic Materials1This standard is issued under the fixed designation E468; 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 practice covers the desirable and minimum information to be communicated between the originator and
3、the user of dataderived from constant-force amplitude axial, bending, or torsion fatigue tests of metallic materials tested in air and at roomtemperature.NOTE 1Practice E466, although not directly referenced in the text, is considered important enough to be listed in this standard.1.2 This internati
4、onal standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committe
5、e.2. Referenced Documents2.1 ASTM Standards:2E6 Terminology Relating to Methods of Mechanical TestingE8/E8M Test Methods for Tension Testing of Metallic MaterialsE466 Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic MaterialsE467 Practice for Verification o
6、f Constant Amplitude Dynamic Forces in an Axial Fatigue Testing SystemE1823 Terminology Relating to Fatigue and Fracture Testing2.2 Special Technical Publications:STP 91STP 91A A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data3STP 588 Manual on Statistical Planning and Analysi
7、s43. Terminology Definitions and Nomenclature3.1 The terms and abbreviations used in this practice are defined in Terminology E6 and in Terminology E1823. In addition,the following nomenclature is used:3.2 criterion of failurecomplete separation, or the presence of a crack of specified length visibl
8、e at a specified magnification.Other criteria may be used but should be clearly defined.3.3 run-outno failure at a specified number of loading cycles.4. Significance and Use4.1 Fatigue test results may be significantly influenced by the properties and history of the parent material, the operationspe
9、rformed during the preparation of the fatigue specimens, and the testing machine and test procedures used during the generationof the data. The presentation of fatigue test results should include citation of basic information on the material, specimens, andtesting to increase the utility of the resu
10、lts and to reduce to a minimum the possibility of misinterpretation or improper applicationof those results.1 This practice is under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of E08.05 E08.05 on Cyclic Deformation andFatigue Crack Formation.Curre
11、nt edition approved Oct. 1, 2011May 1, 2018. Published October 2011July 2018. Originally approved in 1972. Last previous edition approved in 20042011 asE468 909(2004) 11. 1. DOI: 10.1520/E0468-11.10.1520/E0468-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Cus
12、tomer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data, ASTM STP 91 A, ASTM International, 1963. Out of print; available from Un
13、iversity Micro-films, Inc., 300 N. Zeeb Rd., Ann Arbor, MI 48106.A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data, ASTM International, 1963.4 Manual on Statistical Planning and Analysis, ASTM International, 1975.Manual on Statistical Planning and Analysis, ASTM STP 588, ASTM
14、International, 1975.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 technically possible to adequately depict all changes accurately, ASTM recommends that use
15、rs 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 Box C700, West Conshohocken, PA 19428-2959. United States15. Listing of Basic Informat
16、ion About Fatigue Test Specimen5.1 Specification and Properties of Material:5.1.1 Material Prior to Fatigue Test Specimen PreparationThe minimum information to be presented should include thedesignation or specification (for example, A441, SAE 1070, and so forth) or proprietary grade; form of produc
17、t (for example, plate,bar, casting, and so forth); heat number; melting practice; last mechanical working and last heat treatment that produced thematerial in the “as-received” condition (for example, cold-worked and aged, annealed and rolled, and so forth); chemicalcomposition; and surface conditio
18、n (for example, rolled and descaled, ground, and so forth).5.1.1.1 It is desirable but not required (unless by mutual consent of the originator and user of the data) to list the raw materialproduction sequence, billet preparation, results of cleanliness analysis, or a combination thereof, when appli
19、cable.5.1.2 Material in the Fatigue Test Specimen:5.1.2.1 Mechanical PropertiesThe minimum data on the mechanical properties of the material in a condition identical to thatof the fatigue test specimen should include the tensile strength, yield point or yield strength at a specified onset; elongatio
20、n in aspecified gage length; reduction of area when applicable; and the designation of the test used to procure the mechanical properties(for example, Test Methods E8/E8M, Tension Testing of Metallic Materials, and so forth). If notched fatigue tests were conducted,the notched tensile strength also
21、should be listed.5.1.2.2 MetallographyIt is desirable but not required (unless by mutual consent of the originator and user of the data) to listthe grain size (when applicable), phases, and dispersions characteristic of the fatigue test specimen in the “ready-to-test” condition.5.1.2.3 It is desirab
22、le but not required (unless by mutual consent of the originator and user of the data) to show the locations,in the parent material, from which the specimens were taken.5.2 Minimum Information to Be Presented on Design of Fatigue Test Specimen in the “Ready-To-Test” Conditions:5.2.1 Shape, Size, and
23、DimensionsA drawing showing shape, size, and dimensions of the fatigue test specimen should bepresented including details on test section, grip section, fillets, radii, swaged portions, holes, and orientation of the fatigue testspecimen with respect to the direction of maximum working of the materia
24、l. When reporting the test results of notched fatiguespecimens, the geometry of the notch, its dimensions and stress concentration factor, the method of derivation of the stressconcentration factor, and whether the stress concentration factor is based on the gross or net area of the test section sho
25、uld bepresented.5.3 Listing of Information on Specimen Preparation:5.3.1 The minimum information to be presented should list, in chronological order, the operations performed on the fatigue testspecimen, including the type of process used to form the specimen (for example, milling, turning, grinding
26、, etc.), thermal treatment(for example, stress relieving, aging, etc.), and surface treatment (for example, shot-peening, nitriding, coating, etc.). If the finalspecimen surface treatment is polishing, the polishing sequence and direction should be listed. If deterioration of the specimensurface is
27、observed during storage, after preparation but prior to testing, the procedures that were used to eliminate the defects andchanges, if any, in shape, dimensions, or mechanical properties should be listed.5.3.1.1 It is desirable but not required (unless by mutual consent of the originator and user of
28、 the data) to include details of theoperations performed (for example, feed, speed, depth of cut and coolants, thermal cycles, etc.), and the surface residual stressesof the specimen, if measured.5.3.2 Condition of Specimens Prior to Fatigue TestingIt is desirable but not required to list the enviro
29、nment in which thespecimens were stored, type of protection applied to the specimens, and method used to remove that protection. It is desirable butnot required to list the average and range of surface roughness, surface hardness, out-of-flatness, out-of-straightness or warpage,or a combination ther
30、eof, of all fatigue specimens.6. Listing of Information on Test Procedures6.1 Design of the Fatigue Test Program:6.1.1 If statistical techniques were used to design the fatigue test program, the design plan and list of statistical techniques (forexample, randomization of test sequence, blocking, etc
31、.) used to accommodate expected or observed heterogeneities should bepresented. Statistical techniques are described in STP 9191A and STP 588.6.2 Fatigue Testing Machine:6.2.1 Minimum information to be presented should include the type of testing machine, the functional characteristic (forexample, e
32、lectrohydraulic, crank and lever, rotating mass, electro-mechanical, etc.), frequency of force application, and forcingfunction (for example, sine, square, etc.). If tests were performed on more than one machine, the number of testing machines usedshould be listed.6.2.2 Minimum information should in
33、clude the method of dynamic force verification and force monitoring procedures.NOTE 2For guidance on axial force machines, fatigue testing systems, refer to Practice E467.6.3 Fatigue Test:6.3.1 Minimum information to be presented should include the type of test (axial, rotary bending, plane bending,
34、 or torsion),the derivation (or method of computation) of the test section dynamic stresses, and, when applicable, the experimental stressE468 182analysis techniques (for example, electric resistance strain gages, photoelastic coating, etc.) used. The failure criterion and numberof cycles to run-out
35、 used in the test program should be presented.6.3.1.1 It is desirable but not required (unless by mutual consent of the originator and user of the data) to include the procedurefor mounting the specimen in the testing machine, grip details, and precautions taken to ensure that stresses induced by vi
36、bration,friction, eccentricity, etc., were negligible.6.4 Ambient Conditions During the Fatigue TestMinimum information to be presented should include the average value andranges of both temperature and relative humidity that were observed in the laboratory during the test program.6.5 Results of Pos
37、t-Test ExaminationMinimum information to be presented for each fatigue test specimen should include thereason for test termination, either achievement of the failure criterion or run-out, and, if applicable, a description of the failuresurface appearance and location of the crack origin.7. Presentat
38、ion of Fatigue Test Results7.1 Tabular PresentationIt is desirable but not required (unless by mutual consent of the originator and user of the data) thatthe fatigue test results be reported in tabular form. When used, the tabular presentation should include specimen identification, testsequence (th
39、at is, chronological order of testing), dynamic stresses (any two of the following: maximum, minimum, mean,amplitude or range, and stress ratio), fatigue life or cycles to end of test, cause of test termination, and results of post-testexamination (see 6.5), when applicable, for each fatigue test sp
40、ecimen. If test frequency varies from specimen to specimen, itshould also be included in the tabular presentation. If more than one machine was used, the tabular presentation should also includemachine identification for each specimen.7.2 Graphical Presentation:7.2.1 S-N DiagramThe most common graph
41、ical presentation of fatigue test data is the S-N (stresslife) diagram, Fig. 1. Thedependent variable, fatigue life N in cycles, is plotted on the abscissa, a logarithmic scale. The independent variable, maximumstress Smax, stress range Sr, or stress amplitude Sa in psi, ksi, MN/m2 or MPa, is plotte
42、d on the ordinate, an arithmetic or logarithmicscale. A line is fitted by regression analysis or similar mathematical techniques to the fatigue data. The fatigue test results may beexpressed adequately by two straight lines, one of which is a horizontal line representing the fatigue limit (or fatigu
43、e strength atrun-out), a hyperbola, asymptotic to the fatigue limit (or fatigue strength at run-out), a sigmoid, asymptotic to both the tensileFIG. 1 S-N DiagramE468 183strength and the fatigue limit (or fatigue strength at run-out), or by a more general curvilinear relation. If the data are fitted
44、byregression analysis, the equation of the stress-life relation and concomitant statistical measures of dispersion (for example, standarderror of estimate) should be presented.NOTE 3The above described procedure develops the S-N diagram for 50 % survival when the logarithms of the lives are describe
45、d by a normaldistribution. However, similar procedures may be used to develop S-N diagrams for probabilities of survival other than 50 %.7.2.1.1 Graphical presentation of the S-N diagram should include all of the test results as well as the faired or fitted curve.Minimum information to be presented
46、on the S-N diagram should include the designation, specification or proprietary grade of thematerial, tensile strength, surface condition of specimen, stress concentration factor of notch when applicable, type of fatigue test,and citation of dynamic stress parameter held constant during generation o
47、f the S-N curve data (for example, in Fig. 1, stress ratio),test frequency, environment, and test temperature.7.2.2 Constant Life DiagramsS-N diagrams present fatigue life as a function of stress. On the other hand, constant lifediagrams present the maximum and minimum stresses (Fig. 2) or the stres
48、s amplitude and mean stress (Fig. 3) for a given fatiguelife. A third type of constant life diagram superimposes the stress amplitude-mean stress diagram of Fig. 3 on the maximumstress-minimum stress diagram of Fig. 2 by plotting stress amplitude on the ray R = 1 and mean stress on the ray R = + 1.7
49、.2.2.1 When a constant life diagram is presented, it should be accompanied by the S-N diagrams from which it was constructed.Minimum information to be presented on a constant-life diagram should include the designation, specification, or proprietary gradeof the material, tensile strength, surface condition of specimen, stress concentration factor of notch when applicable, type of fatiguetest, and fatigue life (cycles) for each constant life shown, test frequency, environment, and test temperature.8. Example of Fatigue Data Presentation8.1 Data for axial for
