1、Designation:E606041Standard Practice for Designation: E606/E606M 12Standard Test Method forStrain-Controlled Fatigue Testing1This standard is issued under the fixed designation E606/E606M; the number immediately following the designation indicates the yearof original adoption or, in the case of revi
2、sion, 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. 1NOTESection 10 was editorially revisedin July 2005.1. Scope1.1 This practice test method covers the determinat
3、ion of fatigue properties of nominally homogeneous materials by the use oftest specimens subjected to uniaxial forces. It is intended as a guide for fatigue testing performed in support of such activities asmaterials research and development, mechanical design, process and quality control, product p
4、erformance, and failure analysis.While this practice test method is intended primarily for strain-controlled fatigue testing, some sections may provide usefulinformation for force-controlled or stress-controlled testing.1.2 The use of this practice test method is limited to specimens and does not co
5、ver testing of full-scale components, structures,or consumer products.1.3 This practicetest method is applicable to temperatures and strain rates for which the magnitudes of time-dependent inelasticstrains are on the same order or less than the magnitudes of time-independent inelastic strains. No re
6、strictions are placed onenvironmental factors such as temperature, pressure, humidity, medium, and others, provided they are controlled throughout thetest, do not cause loss of or change in dimension with time, and are detailed in the data report.NOTE 1The term inelastic is used herein to refer to a
7、ll nonelastic strains. The term plastic is used herein to refer only to the time-independent (thatis, noncreep) component of inelastic strain. To truly determine a time-independent strain the force would have to be applied instantaneously, which is notpossible. A useful engineering estimate of time-
8、independent strain can be obtained when the strain rate exceeds some value. For example, a strain rateof 1 3 103sec1is often used for this purpose. This value should increase with increasing test temperature.1.4 This practicetest method is restricted to the testing of uniform gage section test speci
9、mens subjected to axial forces as shownin Fig. 1(a). Testing is limited to strain-controlled cycling. The practicetest method may be applied to hourglass specimens, see Fig.1(b), but the user is cautioned about uncertainties in data analysis and interpretation. Testing is done primarily under consta
10、ntamplitude cycling and may contain interspersed hold times at repeated intervals. The practice may be adapted to guide testing formore general cases where strain or temperature may vary according to application specific histories. Data analysis may not followthis practice in such cases. (b), but th
11、e user is cautioned about uncertainties in data analysis and interpretation. Testing is doneprimarily under constant amplitude cycling and may contain interspersed hold times at repeated intervals. The test method maybe adapted to guide testing for more general cases where strain or temperature may
12、vary according to application specific histories.Data analysis may not follow this test method in such cases.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system sh
13、all be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsE3 Guide for Preparation of Metallographic SpecimensE4 Pra
14、ctices for Force Verification of Testing Machines1This practice test method is under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of Subcommittee E08.05 on CyclicDeformation and Fatigue Crack Formation.Current edition approved Oct.June 1, 2004.2012.
15、 Published October 2004.September 2012. Originally approved in 1977. Last previous edition approved in 2004 asE606 92(2004)1. DOI: 10.1520/E0606-04E01.2For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Stand
16、ardsvolume information, refer to the standards Document Summary page on the ASTM website.1This 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
17、 to adequately depict all changes accurately, ASTM recommends that users 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 C
18、onshohocken, PA 19428-2959, United States.E88/E8M Test Methods for Tension Testing of Metallic MaterialsE9 Test Methods of Compression Testing of Metallic Materials at Room TemperatureE83 Practice for Verification and Classification of Extensometer SystemsE111 Test Method for Youngs Modulus, Tangent
19、 Modulus, and Chord ModulusE112 Test Methods for Determining Average Grain SizeE132 Test Method for Poissons Ratio at Room Temperature E157Practice for Assigning Crystallographic Phase Designationsin Metallic SystemsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE209 Pract
20、ice for Compression Tests of Metallic Materials at Elevated Temperatures with Conventional or Rapid Heating Ratesand Strain RatesE337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)E384 Test Method for Knoop and Vickers Hardness of Materials
21、E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness KIcof Metallic MaterialsE466 Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic MaterialsE467 Practice for Verification of Constant Amplitude Dynamic Forces in an Axial Fatigue Testing System
22、E468 Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic MaterialsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE739 Practice for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (-N) Fatig
23、ue DataE1012 Practice for Verification of Testing Frame and Specimen Alignment Under Tensile and Compressive Axial ForceApplicationE1049 Practices for Cycle Counting in Fatigue AnalysisNOTE 1* Dimension d is recommended to be 6.35 mm (0.25 in.). See 7.1. Centers permissible. * This diameter may be m
24、ade greater or less than2d depending on material hardness. In typically ductile materials diameters less than 2d are often employed and in typically brittle materials diametersgreater than 2d may be found desirable.NOTE 2Threaded connections are more prone to inferior axial alignment and have greate
25、r potential for backlash, particularly if the connection withthe grip is not properly designed.FIG. 1 Recommended Low-Cycle Fatigue SpecimensE606/E606M 122E1245 Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals by Automatic Image AnalysisE1823 Terminology Relating
26、to Fatigue and Fracture Testing3. Terminology3.1 The definitions in this practicetest method are in accordance with Terminology E1823.3.2Additional definitions associated with time-dependent deformation behavior observed in tests at elevated homologoustemperatures are as follows:3.2.1hold period, th
27、the time interval within a cycle during which the stress or strain is held constant.3.2.2inelastic strain, 3.2 Additional definitions associated with time-dependent deformation behavior observed in tests at elevated homologoustemperatures are as follows:3.2.1 hold period, th, the time interval withi
28、n a cycle during which the stress or strain is held constant.3.2.2 inelastic strain, in, the strain that is not elastic.3.2.2.1 DiscussionFor isothermal conditions, inthe strain that is not elastic. For isothermal conditions, inis calculatedby subtracting the elastic strain from the total strain.3.2
29、.3 total cycle period,period, ttthe time for the completion of one cycle. The parameter ttcan be separated into hold andnonhold components: can be separated into hold and non-hold (that is, steady and dynamic) components:tt5 (th1 (tnh(1)E0606_E0606M-12_1where:(th= sum of all the hold portions of the
30、 cycle and(tnh= sum of all the nonhold portions of the cycle.ttalso is equal to the reciprocal of the overall frequency when the frequency is held constant.3.2.4TheThe following equations are often used to define the instantaneous stress and strain relationships for many metals andalloys:E0606_E0606
31、M-12_2E0606_E0606M-12_2and the change in strain from any point (1) to any other point (3), as illustrated in Fig. 2, can be calculated as follows:E0606_E0606M-12_3All strain points to the right of and all stress points above the origin are positive. The equation would then show an increasein inelast
32、ic strain from 1 to 3 or:E0606_E0606M-12_4Similarly, during the strain hold period, the change in the inelastic strain will be equal to the change in the stress divided by E*,or:FIG. 2 Analyses of a Total Strain versus Stress Hysteresis LoopContaining a Hold PeriodE606/E606M 123E0606_E0606M-12_5NOTE
33、 2E* represents a material parameter that may be a function of environment and test conditions. It also may vary during a test as a result ofmetallurgical or physical changes in the specimen. In many instances, however, E* is practically a constant quantity and is used rather extensively inisotherma
34、l, constant-rate testing, in the analysis of hysteresis loops. In such cases, a value for E* can best be determined by cycling the specimen priorto the test at stress or strain levels below the elastic limit. E* is NOT the monotonic Youngs modulus.4. Significance and Use4.1 Strain-controlled fatigue
35、 is a phenomenon that is influenced by the same variables that influence force-controlled fatigue.The nature of strain-controlled fatigue imposes distinctive requirements on fatigue testing methods. In particular, cyclic total strainshould be measured and cyclic plastic strain should be determined.
36、Furthermore, either of these strains typically is used to establishcyclic limits; total strain usually is controlled throughout the cycle. The uniqueness of this practicetest method and the results ityields are the determination of cyclic stresses and strains at any time during the tests. Difference
37、s in strain histories other thanconstant-amplitude alter fatigue life as compared with the constant amplitude results (for example, periodic overstrains and blockor spectrum histories). Likewise, the presence of nonzero mean strains and varying environmental conditions may alter fatigue lifeas compa
38、red with the constant-amplitude, fully reversed fatigue tests. Care must be exercised in analyzing and interpreting datafor such cases. In the case of variable amplitude or spectrum strain histories, cycle counting can be performed with Practice E1049.4.2 Strain-controlled fatigue can be an importan
39、t consideration in the design of industrial products. It is important for situationsin which components or portions of components undergo either mechanically or thermally induced cyclic plastic strains that causefailure within relatively few (that is, approximately 105) cycles. Information obtained
40、from strain-controlled fatigue testing maybe an important element in the establishment of design criteria to protect against component failure by fatigue.4.3 Strain-controlled fatigue test results are useful in the areas of mechanical design as well as materials research anddevelopment, process and
41、quality control, product performance, and failure analysis. Results of a strain-controlled fatigue testprogram may be used in the formulation of empirical relationships between the cyclic variables of stress, total strain, plastic strain,and fatigue life. They are commonly used in data correlations
42、such as curves of cyclic stress or strain versus life and cyclic stressversus cyclic plastic strain obtained from hysteresis loops at some fraction (often half) of material life. Examination of the cyclicstressstrain curve and its comparison with monotonic stressstrain curves gives useful informatio
43、n regarding the cyclic stabilityof a material, for example, whether the values of hardness, yield strength, ultimate strength, strain-hardening exponent, andstrength coefficient will increase, decrease, or remain unchanged (that is, whether a material will harden, soften, or be stable)because of cyc
44、lic plastic straining (1).3The presence of time-dependent inelastic strains during elevated temperature testingprovides the opportunity to study the effects of these strains on fatigue life and on the cyclic stress-strain response of the material.Information about strain rate effects, relaxation beh
45、avior, and creep also may be available from these tests. Results of the uniaxialtests on specimens of simple geometry can be applied to the design of components with notches or other complex shapes, providedthat the strains can be determined and multiaxial states of stress or strain and their gradie
46、nts are correctly correlated with theuniaxial strain data.5. Functional Relationships5.1 Empirical relationships that have been commonly used for description of strain-controlled fatigue data are given inAppendix X1. These relationships may not be valid when large time-dependent inelastic strains oc
47、cur. For this reason original datashould be reported to the greatest extent possible. Data reduction methods should be detailed along with assumptions. Sufficientinformation should be developed and reported to permit analysis, interpretation, and comparison with results for other materialsanalyzed u
48、sing currently popular methods.5.2 If use is made of hourglass geometries, original data should be reported along with results analyzed using the relationshipsin Appendix X2.6. Methodology6.1 Testing MachineTesting should be conducted with a tension-compression fatigue testing machine that has been
49、verifiedin accordance with Practices E4 and E467, unless more stringent requirements are called for in this specification. The testingmachine, together with any fixtures used in the test program, must meet the bending strain criteria in 6.3.1. The machine shouldbe one in which specific measures have been taken to minimize backlash in the loading train.NOTE 3Force measuring capability of 45 kN (approximately 10 kips)kips or greater would be sufficient for the recommended specimens (Section7) and most test materials. The machine force capacity used for
