1、Designation: E1823 10aStandard TerminologyRelating to Fatigue and Fracture Testing1This standard is issued under the fixed designation E1823; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This terminology contains definitions, definitions ofterms specific to certain standards, symbols, and abbreviationsapproved for use in standards o
3、n fatigue and fracture testing.The definitions are preceded by two lists. The first is analphabetical listing of symbols used. (Greek symbols are listedin accordance with their spelling in English.) The second is analphabetical listing of relevant abbreviations.1.2 This terminology includes Annex A1
4、 on Units andAnnex A2 on Designation Codes for Specimen Configuration,Applied Loading, and Crack or Notch Orientation.2. Referenced Documents2.1 ASTM Standards:2E6 Terminology Relating to Methods of MechanicalTestingE23 Test Methods for Notched Bar Impact Testing ofMetallic MaterialsE28 Test Methods
5、 for Softening Point of Resins Derivedfrom Naval Stores by Ring-and-Ball ApparatusE208 Test Method for Conducting Drop-Weight Test toDetermine Nil-Ductility Transition Temperature of FerriticSteelsE338 Test Method of Sharp-Notch Tension Testing of High-Strength Sheet MaterialsE399 Test Method for Li
6、near-Elastic Plane-Strain FractureToughness KIcof Metallic MaterialsE436 Test Method for Drop-Weight Tear Tests of FerriticSteelsE467 Practice for Verification of Constant Amplitude Dy-namic Forces in an Axial Fatigue Testing SystemE468 Practice for Presentation of Constant Amplitude Fa-tigue Test R
7、esults for Metallic MaterialsE561 Test Method for K-R Curve DeterminationE602 Test Method for Sharp-Notch Tension Testing withCylindrical SpecimensE604 Test Method for Dynamic Tear Testing of MetallicMaterialsE606 Practice for Strain-Controlled Fatigue TestingE647 Test Method for Measurement of Fati
8、gue CrackGrowth RatesE739 Practice for Statistical Analysis of Linear or Linear-ized Stress-Life ( S-N) and Strain-Life (e-N) Fatigue DataE740 Practice for Fracture Testing with Surface-Crack Ten-sion SpecimensE813 Test Method for JIc,AMeasure of FractureToughnessE992 Practice for Determination of F
9、racture Toughness ofSteels Using Equivalent Energy MethodologyE1049 Practices for Cycle Counting in Fatigue AnalysisE1152 Test Method for Determining-J-R-CurvesE1221 Test Method for Determining Plane-Strain Crack-Arrest Fracture Toughness, KIa, of Ferritic SteelsE1290 Test Method for Crack-Tip Openi
10、ng Displacement(CTOD) Fracture Toughness MeasurementE1291 Test Method for Test Method for Conducting aSaturated Vapor Inhalation Study with Rats3E1304 Test Method for Plane-Strain (Chevron-Notch) Frac-ture Toughness of Metallic MaterialsE1457 Test Method for Measurement of Creep CrackGrowth Times in
11、 MetalsE1681 Test Method for Determining Threshold Stress In-tensity Factor for Environment-Assisted Cracking of Me-tallic MaterialsE1737 Test Method for J-Integral Characterization of Frac-ture Toughness (Discontinued 1998)3E1820 Test Method for Measurement of Fracture Tough-nessE1921 Test Method f
12、or Determination of Reference Tem-perature, To, for Ferritic Steels in the Transition RangeE1942 Guide for Evaluating Data Acquisition SystemsUsed in Cyclic Fatigue and Fracture Mechanics TestingE2208 Guide for Evaluating Non-Contacting Optical StrainMeasurement SystemsE2443 Guide for Verifying Comp
13、uter-Generated Test Re-sults Through The Use Of Standard Data SetsE2472 Test Method for Determination of Resistance toStable Crack Extension under Low-Constraint Conditions1This terminology is under the jurisdiction ofASTM Committee E08 on Fatigueand Fracture and is the direct responsibility of Subc
14、ommittee E08.02 on Standardsand Terminology.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 1996. Last previous edition approved in 2010 as E1823 10. DOI: 10.1520/E1823-10A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、 Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Bo
16、x C700, West Conshohocken, PA 19428-2959, United States.G15 Terminology Relating to Corrosion and CorrosionTesting33. Terminology3.1 Alphabetical Listing of Principal Symbols Used in ThisTerminology:Symbol Terma crack depth, crack length, crack size, estimated cracksizeaeeffective crack sizeannotch
17、lengthaooriginal crack sizeapphysical crack sizea/W normalized crack sizeA force ratio (Pa/Pm)ANnet-section areab remaining ligamentbooriginal uncracked ligamentB specimen thicknessBeeffective thicknessBNnet thickness2c surface-crack lengthC normalized K-gradientD cycle ratio (n/Nf)C*(t) C*(t) Integ
18、ralda/dN fatigue-crack-growth rated crack-tip opening displacement (CTOD)dd specimen gage lengthDa crack extension, estimated crack extensionDK stress-intensity-factor rangeDKthfatigue-crack-growth thresholdDP force rangeastrain amplitudeininelastic strainmmean forceG crack-extension forceGRcrack-ex
19、tension resistanceH* specimen center of pin hole distanceG the path of the J-integralJJ-integralJIcplane-strain fracture toughnessJRcrack-extension resistancekffatigue notch factorkttheoretical stress concentration factor (sometimes ab-breviated stress concentration factor)K, K1, K2, K3,KI, KII, KII
20、Istress-intensity factor (see mode)Kacrack-arrest fracture toughnessKcplane-stress fracture toughnessKEACstress intensity factor threshold for environment-assisted crackingKIaplane-strain crack-arrest fracture toughnessKIEACstress intensity factor threshold for plane strainenvironment-assisted crack
21、ingKIcplane-strain fracture toughnessKIvM, KIv, KIvjplane-strain (chevron-notch) fracture toughnessKmaxmaximum stress-intensity factorKminminimum stress-intensity factorKostress-intensity factor at crack initiationKRcrack-extension resistancen cycles enduredNffatigue lifeP forcePaforce amplitudePmme
22、an forcePMprecrack forcePmaxmaximum forcePminminimum forceq fatigue notch sensitivityr effective unloading slope ratiorccritical slope ratioryplastic-zone adjustmentR force ratio (Pmin/Pmax)s sample standard deviations2sample varianceSymbol TermS specimen spanSaforce amplitudeSffatigue limitSmmean f
23、orceSNfatigue strength at N cyclessccrack strengthsNnominal (net-section) stresssrresidual strengthsssharp-notch strengthsTStensile strengthsx, sy, sznormal stresses (refer to )sYeffective yield strengthsYSyield strengthT specimen temperaturetTtransition timetttotal cycle periodtxy,tyz, tzxshear str
24、esses (refer to Fig. 1)u displacement in x directionv displacement in y direction2vmcrack-mouth opening displacementVcforce-line displacement due to creepw displacement in z directionW specimen widthY* stress-intensity factor coefficientY*mminimum stress-intensity factor coefficient3.2 Alphabetical
25、Listing of Abbreviations Used:CMOD crack-mouth opening displacementCOD see CTODCTOD crack-tip opening displacementDT dynamic tearDWTT drop-weight tear testEAC environment-assisted crackingK-EE equivalent-energy fracture toughnessNTS notch tensile strengthPS part-through surfaceSCC stress corrosion c
26、rackingSZW stretch zone width3.3 DefinitionsEach definition is followed by the desig-nation(s) of the standard(s) of origin. The listing of definitionsis alphabetical.alternating forceSee loading amplitude.applied-K curvea curve (a fixed-force or fixed-displacement crack-extension-force curve) obtai
27、ned from afracture mechanics analysis for a specific configuration. Thecurve relates the stress-intensity factor to crack size andeither applied force or displacement.DISCUSSIONThe resulting analytical expression is sometimes calleda K calibration and is frequently available in handbooks for stress-
28、intensity factors. E647basic datathe sampled value of a sensor taken at fixed orvariable time intervals. Each sample represents the valuemeasured by the sensor at that instant of time.DISCUSSIONin Test Method E2208, for optical, non-contactingmethods, a two dimensional array of image intensity data
29、is generallythe basic data. E1942, E2208, E2443blockin fatigue loading, a specified number of constantamplitude loading cycles applied consecutively, or a spec-trum loading sequence of finite length that is repeatedidentically. E1823blunting linein fracture testing, a line that approximatesapparent
30、crack advance due to crack-tip blunting in theabsence of slow stable crack tearing. The line is definedbased on the assumption that the crack advance is equal toE1823 10a2one half of the crack-tip opening displacement.This estimateof pseudo-crack advance, DaB, is based on the effectiveyield strength
31、 of the material tested. E813DaB5 J/2 sY(1)circulation rate L3T1in fatigue testing, the volume rateof change of the environment chamber volume. E1823clippingin fatigue spectrum loading, the process of decreas-ing or increasing the magnitude of all loads (strains) that are,respectively, above or belo
32、w a specified level, referred to asclipping level; the loads (strains) are decreased or increasedto the clipping level (see Fig. 2). E1823compliance (LF1, n the ratio of displacement increment toforce increment. E1820confidence intervalan interval estimate of a populationparameter computed so that t
33、he statement 88the populationparameter included in this interval” will be true, on theaverage, in a stated proportion of the times such computa-tions are made based on different samples from the popula-tion. E1823confidence level (or coefficient)the stated proportion of thetimes the confidence inter
34、val is expected to include thepopulation parameter. E1823confidence limitsthe two statistics that define a confidenceinterval. E1823control force, Pm Fa calculated value of maximum forceused in Test Method E1820 to stipulate allowable precrack-ing limits. E1820, E1921constant amplitude loading in fa
35、tigue loading, a loading(straining) in which all of the peak forces (strains) are equaland all of the valley forces (strains) are equal. E1049constant life diagram in fatigue, a plot (usually on rectan-gular coordinates) of a family of curves each of which is fora single fatigue life, N, relating st
36、ress amplitude, Sa, to meanstress, Sm, or maximum stress, Smax, or both, to minimumstress, Smin. The constant life fatigue diagram is usuallyderived from a family of S-N curves each of which repre-sents a different stress ratio (A or R) for a 50 % probabilityof survival. E1820control force, Pm Fa ca
37、lculated value of maximum forceused in Test Method E1820 to stipulate allowable precrack-ing limits. source E1820, E1921corrosion fatiguethe process by which fracture occursprematurely under conditions of simultaneous corrosion andrepeated cyclic loading at lower stress levels or fewer cyclesthan wo
38、uld be required in the absence of the corrosiveenvironment. G15counting methodin fatigue spectrum loading, a method ofcounting the occurrences and defining the magnitude ofvarious loading parameters from a load-time history; (someof the counting methods are: level crossing count, peakcount, mean cro
39、ssing peak count, range count, range-paircount, rain-flow count, racetrack count). E1049crack displacement Lthe force-induced separation vectorbetween two points (on the facing surfaces of a crack) thatwere initially coincident.DISCUSSIONIn Practice E561, displacement is the distance that achosen me
40、asurement point on the specimen displaces normal to thecrack plane. Measurement points on the C(W) and C(T) specimenconfigurations are identified as locations V0, V1, and V2. E561crack extension, Da Lan increase in crack size.DISCUSSIONFor example, in Practice E561, Dapor Daeis thedifference between
41、 the crack size, either ap(physical crack size) or ae(effective crack size), and ao(original crack size). E561crack-extension force, G FL1or FLL2the elastic en-ergy per unit of new separation area that is made available atNOTESee definition of mode.FIG. 1 Customary Coordinate System and Stress on a
42、Small Volume Element Located on the x Axis Just Ahead of the Crack FrontE1823 10a3the front of an ideal crack in an elastic solid during a virtualincrement of forward crack extension.DISCUSSIONThis force concept implies an analytical model forwhich the stress-strain relations are regarded as elastic
43、. The precedingdefinition of G applies to either static cracks or running cracks. Frompast usage, G is commonly associated with linear-elastic methods ofanalysis, although the J (see J-integral) also may be used for suchanalyses. E1823crack-extension resistance, KRFL3/2, GRFL1orJRFL1a measure of the
44、 resistance of a material to crackextension expressed in terms of the stress-intensity factor, K;crack-extension force, G; or values of J derived using theJ-integral concept.DISCUSSIONSee definition of R-curve. E561crack initiationthe onset of crack propagation from apreexisting macroscopic crack cr
45、eated in the specimen by astipulated procedure. E1921crack-mouth opening displacement (CMOD),2vmLtheMode 1 (also called opening-mode) component of crackdisplacement resulting from the total deformation (elasticplus plastic), measured under force at the location on a cracksurface that has the greates
46、t elastic displacement per unitforce.DISCUSSIONIn part-through surface-crack (PS) specimens, CMODis measured on the specimen surface at the midpoint of the cracklength. E740crack-plane orientationan identification of the plane anddirection of fracture or crack extension in relation to productconfigu
47、ration. This identification is designated by a hyphen-ated code with the first letter(s) representing the directionnormal to the crack plane and the second letter(s) designat-ing the expected direction of crack propagation.DISCUSSIONSee also E1823 Annex A2,(A2.4 on crack or notchorientation). E399,
48、E1457crack size, a Lprincipal lineal dimension used in thecalculation of fracture mechanics parameters for through-thickness cracks as defined in the applicable standard. SeeFig. A2.2 for schematic representations.DISCUSSIONFor example, in the C(T) specimen a is the averagemeasurement from the line
49、connecting the bearing points of forceapplication; in the M(T) specimen, a is the average measurement fromthe perpendicular bisector of the central crack.DISCUSSIONIn practice, the value of a is obtained from proceduresfor measurement of physical crack size, ap, original crack size, ao, andeffective crack size, ae, as appropriate to the situation being considered.DISCUSSIONFor part-through cracks see crack depth (a) and surfacecrack length (2c) in Definitions of Terms (Specific to the indicatedstandards.)DISC
