1、Designation: E468 11Standard 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, the ye
2、ar 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 infor-mation to be communicated between the originator and the us
3、erof data derived from constant-force amplitude axial, bending,or torsion fatigue tests of metallic materials tested in air and atroom temperature.NOTE 1Practice E466, although not directly referenced in the text, isconsidered important enough to be listed in this standard.2. Referenced Documents2.1
4、 ASTM Standards:2E6 Terminology Relating to Methods of MechanicalTestingE8/E8M Test Methods for Tension Testing of MetallicMaterialsE466 Practice for Conducting Force Controlled ConstantAmplitude Axial Fatigue Tests of Metallic MaterialsE467 Practice for Verification of Constant Amplitude Dy-namic F
5、orces in an Axial Fatigue Testing SystemE1823 Terminology Relating to Fatigue and Fracture Test-ing2.2 Special Technical Publications:STP 91 A Guide for Fatigue Testing and the StatisticalAnalysis of Fatigue Data3STP 588 Manual on Statistical Planning and Analysis43. Terminology Definitions and Nome
6、nclature3.1 The terms and abbreviations used in this practice aredefined in Terminology E6 and in Terminology E1823.Inaddition, the following nomenclature is used:3.2 criterion of failurecomplete separation, or the pres-ence of a crack of specified length visible at a specifiedmagnification. Other c
7、riteria may be used but should be clearlydefined.3.3 run-outno failure at a specified number of loadingcycles.4. Significance and Use4.1 Fatigue test results may be significantly influenced bythe properties and history of the parent material, the operationsperformed during the preparation of the fat
8、igue specimens, andthe testing machine and test procedures used during thegeneration of the data. The presentation of fatigue test resultsshould include citation of basic information on the material,specimens, and testing to increase the utility of the results andto reduce to a minimum the possibili
9、ty of misinterpretation orimproper application of those results.5. Listing of Basic Information About Fatigue TestSpecimen5.1 Specification and Properties of Material:5.1.1 Material Prior to Fatigue Test SpecimenPreparationThe minimum information to be presentedshould include the designation or spec
10、ification (for example,A441, SAE 1070, and so forth) or proprietary grade; form ofproduct (for example, plate, bar, casting, and so forth); heatnumber; melting practice; last mechanical working and lastheat treatment that produced the material in the “as-received”condition (for example, cold-worked
11、and aged, annealed androlled, and so forth); chemical composition; and surfacecondition (for example, rolled and descaled, ground, and soforth).5.1.1.1 It is desirable but not required (unless by mutualconsent of the originator and user of the data) to list the rawmaterial production sequence, bille
12、t preparation, results ofcleanliness analysis, or a combination thereof, when appli-cable.5.1.2 Material in the Fatigue Test Specimen:5.1.2.1 Mechanical PropertiesThe minimum data on themechanical properties of the material in a condition identical tothat of the fatigue test specimen should include
13、the tensilestrength, yield point or yield strength at a specified onset;elongation in a specified gage length; reduction of area when1This practice is under the jurisdiction ofASTM Committee E08 on Fatigue andFracture and is the direct responsibility of E08.05 E08.05 on Cyclic Deformationand Fatigue
14、 Crack Formation.Current edition approved Oct. 1, 2011. Published October 2011. Originallyapproved in 1972. Last previous edition approved in 2004 as E468 909(2004)1.DOI: 10.1520/E0468-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service
15、astm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data, ASTMSTP 91 A, ASTM International, 1963. Out of print; available from UniversityMicro- films, Inc.,
16、 300 N. Zeeb Rd., Ann Arbor, MI 48106.4Manual on Statistical Planning and Analysis, ASTM STP 588, ASTM Interna-tional, 1975.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.applicable; and the designation of the test used to procure t
17、hemechanical properties (for example, Test Methods E8/E8M,Tension Testing of Metallic Materials, and so forth). If notchedfatigue tests were conducted, the notched tensile strength alsoshould be listed.5.1.2.2 MetallographyIt is desirable but not required(unless by mutual consent of the originator a
18、nd user of thedata) to list the grain size (when applicable), phases, anddispersions characteristic of the fatigue test specimen in the“ready-to-test” condition.5.1.2.3 It is desirable but not required (unless by mutualconsent of the originator and user of the data) to show thelocations, in the pare
19、nt material, from which the specimenswere taken.5.2 Minimum Information to Be Presented on Design ofFatigue Test Specimen in the “Ready-To-Test” Conditions:5.2.1 Shape, Size, and DimensionsA drawing showingshape, size, and dimensions of the fatigue test specimen shouldbe presented including details
20、on test section, grip section,fillets, radii, swaged portions, holes, and orientation of thefatigue test specimen with respect to the direction of maximumworking of the material. When reporting the test results ofnotched fatigue specimens, the geometry of the notch, itsdimensions and stress concentr
21、ation factor, the method ofderivation of the stress concentration factor, and whether thestress concentration factor is based on the gross or net area ofthe test section should be presented.5.3 Listing of Information on Specimen Preparation:5.3.1 The minimum information to be presented should list,i
22、n chronological order, the operations performed on the fatiguetest specimen, including the type of process used to form thespecimen (for example, milling, turning, grinding, etc.), ther-mal treatment (for example, stress relieving, aging, etc.), andsurface treatment (for example, shot-peening, nitri
23、ding, coat-ing, etc.). If the final specimen surface treatment is polishing,the polishing sequence and direction should be listed. Ifdeterioration of the specimen surface is observed duringstorage, after preparation but prior to testing, the proceduresthat were used to eliminate the defects and chan
24、ges, if any, inshape, dimensions, or mechanical properties should be listed.5.3.1.1 It is desirable but not required (unless by mutualconsent of the originator and user of the data) to include detailsof the operations performed (for example, feed, speed, depth ofcut and coolants, thermal cycles, etc
25、.), and the surface residualstresses of the specimen, if measured.5.3.2 Condition of Specimens Prior to Fatigue TestingIt isdesirable but not required to list the environment in which thespecimens were stored, type of protection applied to thespecimens, and method used to remove that protection. It
26、isdesirable but not required to list the average and range ofsurface roughness, surface hardness, out-of-flatness, out-of-straightness or warpage, or a combination thereof, of all fatiguespecimens.6. Listing of Information on Test Procedures6.1 Design of the Fatigue Test Program:6.1.1 If statistical
27、 techniques were used to design the fatiguetest program, the design plan and list of statistical techniques(for example, randomization of test sequence, blocking, etc.)used to accommodate expected or observed heterogeneitiesshould be presented. Statistical techniques are described inSTP 91 and STP 5
28、88.6.2 Fatigue Testing Machine:6.2.1 Minimum information to be presented should includethe type of testing machine, the functional characteristic (forexample, electrohydraulic, crank and lever, rotating mass, etc.),frequency of force application, and forcing function (forexample, sine, square, etc.)
29、. If tests were performed on morethan one machine, the number of testing machines used shouldbe listed.6.2.2 Minimum information should include the method ofdynamic force verification and force monitoring procedures.NOTE 2For guidance on axial force machines, refer to Practice E467.6.3 Fatigue Test:
30、6.3.1 Minimum information to be presented should includethe type of test (axial, rotary bending, plane bending, ortorsion), the derivation (or method of computation) of the testsection dynamic stresses, and, when applicable, the experimen-tal stress analysis techniques (for example, electric resista
31、ncestrain gages, photoelastic coating, etc.) used. The failurecriterion and number of cycles to run-out used in the testprogram should be presented.6.3.1.1 It is desirable but not required (unless by mutualconsent of the originator and user of the data) to include theprocedure for mounting the speci
32、men in the testing machine,grip details, and precautions taken to ensure that stressesinduced by vibration, friction, eccentricity, etc., were negli-gible.6.4 Ambient Conditions During the Fatigue TestMinimum information to be presented should include theaverage value and ranges of both temperature
33、and relativehumidity that were observed in the laboratory during the testprogram.6.5 Results of Post-Test ExaminationMinimum informa-tion to be presented for each fatigue test specimen shouldinclude the reason for test termination, either achievement ofthe failure criterion or run-out, and, if appli
34、cable, a descriptionof the failure surface appearance and location of the crackorigin.7. Presentation of Fatigue Test Results7.1 Tabular PresentationIt is desirable but not required(unless by mutual consent of the originator and user of thedata) that the fatigue test results be reported in tabular f
35、orm.When used, the tabular presentation should include specimenidentification, test sequence (that is, chronological order oftesting), dynamic stresses (any two of the following: maxi-mum, minimum, mean, amplitude or range, and stress ratio),fatigue life or cycles to end of test, cause of test termi
36、nation,and results of post-test examination (see 6.5), when applicable,for each fatigue test specimen. If test frequency varies fromspecimen to specimen, it should also be included in the tabularpresentation. If more than one machine was used, the tabularpresentation should also include machine iden
37、tification foreach specimen.7.2 Graphical Presentation:E468 1127.2.1 S-N DiagramThe most common graphical presen-tation of fatigue test data is the S-N (stresslife) diagram, Fig.1. The dependent variable, fatigue life N in cycles, is plotted onthe abscissa, a logarithmic scale. The independent varia
38、ble,maximum stress Smax, stress range Sr, or stress amplitude Sainpsi, ksi, MN/m2or MPa, is plotted on the ordinate, anarithmetic or logarithmic scale. A line is fitted by regressionanalysis or similar mathematical techniques to the fatigue data.The fatigue test results may be expressed adequately b
39、y twostraight lines, one of which is a horizontal line representing thefatigue limit (or fatigue strength at run-out), a hyperbola,asymptotic to the fatigue limit (or fatigue strength at run-out),a sigmoid, asymptotic to both the tensile strength and thefatigue limit (or fatigue strength at run-out)
40、, or by a moregeneral curvilinear relation. If the data are fitted by regressionanalysis, the equation of the stress-life relation and concomi-tant statistical measures of dispersion (for example, standarderror of estimate) should be presented.NOTE 3The above described procedure develops the S-N dia
41、gram for50 % survival when the logarithms of the lives are described by a normaldistribution. However, similar procedures may be used to develop S-Ndiagrams for probabilities of survival other than 50 %.7.2.1.1 Graphical presentation of the S-N diagram shouldinclude all of the test results as well a
42、s the faired or fitted curve.Minimum information to be presented on the S-N diagramshould include the designation, specification or proprietarygrade of the material, tensile strength, surface condition ofspecimen, stress concentration factor of notch when applicable,type of fatigue test, and citatio
43、n of dynamic stress parameterheld constant during generation of the S-N curve data (forexample, in Fig. 1, stress ratio), test frequency, environment,and test temperature.7.2.2 Constant Life DiagramsS-N diagrams present fa-tigue life as a function of stress. On the other hand, constantlife diagrams
44、present the maximum and minimum stresses(Fig. 2) or the stress amplitude and mean stress (Fig. 3) for agiven fatigue life. A third type of constant life diagramsuperimposes the stress amplitude-mean stress diagram of Fig.3 on the maximum stress-minimum stress diagram of Fig. 2 byplotting stress ampl
45、itude on the ray R = 1 and mean stress onthe ray R =+1.7.2.2.1 When a constant life diagram is presented, it shouldbe accompanied by the S-N diagrams from which it wasconstructed. Minimum information to be presented on aconstant-life diagram should include the designation, specifi-cation, or proprie
46、tary grade of the material, tensile strength,surface condition of specimen, stress concentration factor ofnotch when applicable, type of fatigue test, and fatigue life(cycles) for each constant life shown, test frequency, environ-ment, and test temperature.8. Example of Fatigue Data Presentation8.1
47、Data for axial force fatigue tests of A36 structuralcarbon steel are presented in a suggested form in theAppendix.FIG. 1 S-N DiagramE468 113FIG. 2 Constant-Life DiagramFIG. 3 Constant-Life DiagramE468 114APPENDIX(Nonmandatory Information)X1. SUGGESTED FORM FOR PRESENTATION OF FATIGUE TEST RESULTS OF
48、 METALLIC MATERIALSMATERIALGrade Designation: A36 Structural Carbon SteelHeat Number: 490T1481 Form of Product:38 in. (9.5 mm)thick plateMelting Practice: Air-melted, semi-killed Surface Condi-tion: As-rolledLast Mechanical and Thermal Treatment: Hot-rolled andair-cooledChemical Composition: 0.22 %
49、C, 0.52 % Mn, 0.008 % P,0.013 % S, 0.029 % CuTensile Strength: 63 000 psi (434 MPa)Yield Point: 37 800psi (261 MPa)Elongation: 40.1 % in 2-in. (51-mm) gage length.Reduction of Area: 64.8 %Remarks: ASTM micrograin size number, 8.5 (surface andcenter of plate). Mechanical test performed in accordance withTest Methods E8/E8M, Tension Testing of Metallic Materials,on round tension test specimens, Fig. 8, Test Methods E8/E8M.FATIGUE SPECIMENShape, Size, and Dimensions: see Fig. X1.1.Stress Concentration Factor: unnotchedPreparation:Forming: Edges milled, thickness
