ASTM E6-2007a Standard Terminology Relating to Methods of Mechanical Testing《机械试验方法的相关标准术语》.pdf

1、Designation:E607aStandard Terminology Relating toMethods of Mechanical Testing1This standard is issued under the fixed designation E 6; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in parenthese

2、s indicates the year of last reapproval.Asuperscriptepsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This terminology covers the principal terms relating tomethods of mechanica

3、l testing of solids. The general defini-tions are restricted and interpreted, when necessary, to makethem particularly applicable and practicable for use in stan-dards requiring or relating to mechanical tests. These defini-tions are published to encourage uniformity of terminology inproduct specifi

4、cations.1.2 Terms relating to fatigue and fracture testing are definedin Terminology E 1823.2. Referenced Documents2.1 ASTM Standards:2E8 Test Methods for Tension Testing of Metallic MaterialsE8M Test Methods for Tension Testing of Metallic Mate-rials MetricE 796 Test Method for Ductility Testing of

5、 Metallic FoilE 1823 Terminology Relating to Fatigue and Fracture Test-ing3. Index of Terms3.1 The definitions of the following terms, which are listedalphabetically, appear in the indicated sections of 4.1.Term Sectionaccuracy Galignment Bangle of bend Dangle of twist Bangular strain see strainaxia

6、l strain see strainbearing area Fbearing force Fbearing strain Fbearing strength Fbearing stress Fbearing yield strength Fbend test Dbending strain see strainbias, statistical Gbiaxial stretching Dbreaking load BBrinell hardness number CBrinell hardness test Ccalibration Gcalibration factor Gchord m

7、odulus see modulus of elasticitycompressive strength Bcompressive stress see stresscompressometer Gconstraint Acreep Ecreep recovery Ecreep rupture strength Ecreep strength Edeep drawing Ddeflectometer Gdirect verification Gdiscontinuous yielding Bdiscontinuous yielding stress Bductility Adynamic me

8、chanical measurement Geccentricity Bedge distance Fedge distance ratio Felastic calibration device Gelastic constants see modulus of elasticity and Poissonsratioelastic force-measurement device Gelastic limit Aelastic modulus see modulus of elasticityelastic true strain Aelongation Bengineering stra

9、in see strainengineering stress see stressextensometer Gextensometer system Gfatigue ductility Dfatigue life Bforming limit curve Dforming limit diagram Dfracture ductility Afracture strength Afracture stress see stressfree bend Dforce Agage length Gguided bend Dhardness Cindentation hardness Cindir

10、ect verification Ginitial recovery E1This terminology is under the jurisdiction of ASTM Committee E28 onMechanical Testing and is the direct responsibility of Subcommittee E28.91 onTerminology except where designated otherwise. A subcommittee designation inparentheses following a definition indicate

11、s the subcommittee with responsibility forthat definition.Current edition approved June 1, 2007. Published June 2007. Originallyapproved 1923. Last previous edition approved 2007 as E607.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea

12、stm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.initial strain Einitial stress EKnoop hardness number CKnoo

13、p hardness test Climiting dome height Dlinear (tensile or compressive) strain see strainload Alower yield strength Bmacrostrain see strainmalleability see ductilitymandrel (in bend testing) Dmechanical hysteresis Amechanical properties Amechanical testing Amicrostrain see strainmodulus of elasticity

14、 Amodulus of rigidity see modulus of elasticitymodulus of rupture in bending Dmodulus of rupture in torsion Bnecking Bnominal stress see stressnormal stress see stressphysical properties see mechanical propertiespin see mandrel (in bend testing)plastic true strain Aplunger see mandrel (in bend testi

15、ng)precision Gprimary force standard Gprincipal stress see stressPoissons ratio Aproportional limit Aradius of bend Drate of creep Ereduction of area Brelaxation rate Erelaxed stress Eremaining stress Eresidual strain see strainresidual stress see stressRockwell hardness number CRockwell hardness te

16、st CRockwell superficial hardness num-bersee Rockwell hardness numberRockwell superficial hardness test Csemi-guided bend DScleroscope hardness number CScleroscope hardness test Csecondary force standard Gset Asecant modulus see modulus of elasticityshear fracture Bshear modulus Ashear strain see st

17、rainshear strength Bshear stress see stressslenderness ratio Bstatic fatigue strength see creep rupture strengthstrain Astrain gage fatigue life see fatigue lifestrain hardening Astress Astress relaxation Estress-rupture strength see creep rupture strengthstress-strain diagram Atangent modulus see m

18、odulus of elasticitytensile strength Btensile stress see stresstension testing machine Atesting machine Atorque Atorsional modulus see modulus of elasticitytorsional stress see stresstotal elongation Btransverse strain see straintrue strain see straintrue stress see stressuniform elongation Bupper y

19、ield strength Bverification GVickers hardness number CVickers hardness test Cwrap-around bend Dyield point Byield point elongation Byield strength B (also see upper yield strength andlower yield strength)Youngs modulus Azero time E4. Terminology4.1 Terms and Definitions:A. GENERAL DEFINITIONSconstra

20、int, nany restriction to the deformation of a body.(E28.11)ductility, nthe ability of a material to deform plasticallybefore fracturing. (E28.02)DISCUSSIONDuctility is usually evaluated by measuring (1) theelongation or reduction of area from a tension test, (2) the depth of cupfrom a cupping test,

21、(3) the radius or angle of bend from the bend test,or (4) the fatigue ductility from the fatigue ductility test (see TestMethod E 796).DISCUSSIONMalleability is the ability to deform plastically underrepetitive compressive forces.elastic limit FL2, nthe greatest stress which a material iscapable of

22、sustaining without any permanent strain remain-ing upon complete release of the stress.DISCUSSIONDue to practical considerations in determining theelastic limit, measurements of strain, using a small force rather thanzero force, are usually taken as the initial and final reference.fracture ductility

23、, ef, nthe true plastic strain at fracture.fracture strength, SfFL2, nthe normal stress at thebeginning of fracture. Fracture strength is calculated fromthe force at the beginning of fracture during a tension testand the original cross-sectional area of the specimen.force F, nin mechanical testing,

24、a vector quantity offundamental nature characterized by a magnitude, a direc-tion, a sense, and a discrete point of application, that actsexternally upon a test object and creates stresses in it.(E28.91)DISCUSSIONForce is a derived unit of the SI system. Units of forcein the SI system are newtons (N

25、).DISCUSSIONWhere applicable, the noun force is preferred to load interminology for mechanical testing.least count, nthe smallest change in indication that cancustomarily be determined and reported.DISCUSSIONIn machines with close graduations it may be the valueof a graduation interval; with open gr

26、aduations or with magnifiers forreading, it may be an estimated fraction, rarely as fine as one tenth, ofa graduated interval; and with verniers it is customarily the differencebetween the scale and vernier graduation measured in terms of scaleunits. If the indicating mechanism includes a stepped de

27、tent, the detentaction may determine the least count.load F , nin mechanical testing, an external force or systemof forces or pressures, or both, that act upon the test object.E607a2(E28.91)DISCUSSIONLoad is a deprecated term and, where applicable, itshould be replaced by force, particularly where i

28、t is used as a noun. Forreasons of editorial simplicity or traditional usage, replacement of loadby force may not always be desirable when used as a verb, adjective,or other part of speech (for example, to load a specimen, loading rate,load cell).mechanical hysteresis, nthe energy absorbed in a comp

29、letecycle of loading and unloading. (E28.03)DISCUSSIONA complete cycle of loading and unloading includesany stress cycle regardless of the mean stress or range of stress.mechanical properties, nthose properties of a material thatare associated with elastic and inelastic reaction when forceis applied

30、, or that involve the relationship between stress andstrain.DISCUSSIONThese properties have often been referred to as “physi-cal properties,” but the term “mechanical properties” is preferred.mechanical testing, ndetermination of the properties or themechanical states of a material that are associat

31、ed withelastic and inelastic reactions to force or that involverelationships between stress and strain. (E28.91)modulus of elasticity FL2, nthe ratio of stress to corre-sponding strain below the proportional limit.DISCUSSIONThe stress-strain relations of many materials do notconform to Hookes law th

32、roughout the elastic range, but deviatetherefrom even at stresses well below the elastic limit. For suchmaterials the slope of either the tangent to the stress-strain curve at theorigin or at a low stress, the secant drawn from the origin to anyspecified point on the stress-strain curve, or the chor

33、d connecting anytwo specified points on the stress-strain curve is usually taken to be the“modulus of elasticity.” In these cases the modulus should be desig-nated as the “tangent modulus,” the“ secant modulus,” or the “chordmodulus,” and the point or points on the stress-strain curve described.Thus

34、, for materials where the stress-strain relationship is curvilinearrather than linear, one of the four following terms may be used:(a) initial tangent modulus FL2, nthe slope of the stress-straincurve at the origin.(b) tangent modulus FL2, nthe slope of the stress-strain curve atany specified stress

35、 or strain.(c) secant modulus FL2, nthe slope of the secant drawn from theorigin to any specified point on the stress-strain curve.(d) chord modulus FL2, nthe slope of the chord drawn betweenany two specified points on the stress-strain curve below the elasticlimit of the material. (E28.03)DISCUSSIO

36、NModulus of elasticity, like stress, is expressed in forceper unit of area (pounds per square inch, etc.).Poissons ratio, , nthe negative of the ratio of transversestrain to the corresponding axial strain resulting from anaxial stress below the proportional limit of the material.(E28.03)DISCUSSIONPo

37、issons ratio may be negative for some materials, forexample, a tensile transverse strain will result from a tensile axialstrain.DISCUSSIONPoissons ratio will have more than one value if thematerial is not isotropic.proportional limit FL2, nthe greatest stress which amaterial is capable of sustaining

38、 without any deviation fromproportionality of stress to strain (Hookes law).DISCUSSIONMany experiments have shown that values observed forthe proportional limit vary greatly with the sensitivity and accuracy ofthe testing equipment, eccentricity of loading, the scale to which thestress-strain diagra

39、m is plotted, and other factors. When determinationof proportional limit is required, the procedure and the sensitivity of thetest equipment should be specified.set, nstrain remaining after complete release of the forceproducing the deformation.DISCUSSIONDue to practical considerations, such as dist

40、ortion in thespecimen and slack in the strain indicating system, measurements ofstrain at a small force rather than zero force are often taken.DISCUSSIONSet is often referred to as permanent set if it shows nofurther change with time. Time elapsing between removal of force andfinal reading of set sh

41、ould be stated.shear modulus, G FL2, nthe ratio of shear stress tocorresponding shear strain below the proportional limit, alsocalled torsional modulus and modulus of rigidity. (E28.03)DISCUSSIONThe value of the shear modulus may depend on thedirection in which it is measured if the material is not

42、isotropic. Wood,many plastics and certain metals are markedly anisotropic. Deviationsfrom isotropy should be suspected if the shear modulus differs from thatdetermined by substituting independently measured values of Youngsmodulus, E, and Poissons ratio, , in the relation:G 5 E/21 1 !#DISCUSSIONIn g

43、eneral, it is advisable in reporting values of shearmodulus to state the range of stress over which it is measured.strain, e, nthe per unit change, due to force, in the size orshape of a body referred to its original size or shape. Strainis a nondimensional quantity, but it is frequently expressedin

44、 inches per inch, metres per metre, or percent.DISCUSSIONIn this standard, “original” refers to dimensions orshape of cross section of specimens at the beginning of testing.DISCUSSIONStrain at a point is defined by six components of strain:three linear components and three shear components referred

45、to a set ofcoordinate axes.DISCUSSIONIn the usual tension, compression, or torsion test it iscustomary to measure only one component of strain and to refer to thisas “the strain.” In a tension or a compression test this is usually theaxial component.DISCUSSIONStrain has an elastic and a plastic comp

46、onent. For smallstrains the plastic component can be imperceptibly small.DISCUSSIONLinear thermal expansion, sometimes called “thermalstrain,” and changes due to the effect of moisture are not to beconsidered strain in mechanical testing.angular strain, nuse shear strain.axial strain, nlinear strain

47、 in a plane parallel to the longitu-dinal axis of the specimen. (E28.04)bending strain, nthe difference between the strain at thesurface of the specimen and the axial strain. (E28.03,E28.10elastic true strain, ee, nelastic component of the true strain.engineering strain, e, na dimensionless value th

48、at is thechange in length (DL) per unit length of original lineardimension (L0) along the loading axis of the specimen; thatis, e=(DL)/L0. (E28.02)linear (tensile or compressive) strain, nthe change per unitlength due to force in an original linear dimension.(E28.04)DISCUSSIONAn increase in length i

49、s considered positive.E607a3macrostrain, nthe mean strain over any finite gage length ofmeasurement large in comparison with interatomic dis-tances. (E28.13)DISCUSSIONMacrostrain can be measured by several methods,including electrical-resistance strain gages and mechanical or opticalextensometers. Elastic macrostrain can be measured by X-ray diffrac-tion.DISCUSSIONWhen either of the terms macrostrain or microstrain isfirst used in a document, it is recommended that the physical dimensi