1、Designation: E6 15Standard Terminology Relating toMethods of Mechanical Testing1This standard is issued under the fixed designation E6; 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 () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This terminology covers the principal terms relating tomethods of mecha
3、nical 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 spe
4、cifications.1.2 Terms relating to fatigue and fracture testing are definedin Terminology E1823.2. Referenced Documents2.1 ASTM Standards:2E8/E8M Test Methods for Tension Testing of Metallic Ma-terialsE796 Test Method for Ductility Testing of Metallic Foil(Withdrawn 2009)3E1823 Terminology Relating t
5、o Fatigue and Fracture Testing2.2 ISO Standard:4ISO/IEC Guide 99:2007 International Vocabulary ofmetrologyBasic and general concepts and terms (VIM)2.3 NIST Technical Notes:NIST Technical Note 1297 Guidelines for Evaluating andExpressing the Uncertainty of NIST Measurement Re-sults53. Index of Cross
6、-References and Associated Definitions3.1 The terms listed below are associated with terminologythat is fundamental or commonly used. The definition for theterm of interest is related to or is given below the definition forthe fundamental term cited.Termangular strain see strainaxial strain see stra
7、inbending strain see strainchord modulus see modulus of elasticitydirect verification see verificationcompressive stress see stresselastic constants see modulus of elasticity and Poissonsratioelastic modulus see modulus of elasticityengineering strain see strainengineering stress see stressfracture
8、stress see stressindirect verification see verificationlinear (tensile or compressive) strain see strainmacrostrain see strainmalleability see ductilitymicrostrain see strainmodulus of rigidity see modulus of elasticitynominal stress see stressnormal stress see stressphysical properties see mechanic
9、al propertiespin see mandrel (in bend testing)plunger see mandrel (in bend testing)principal stress see stressresidual strain see strainresidual stress see stressRockwell superficialhardness numbersee Rockwell hardness numbersecant modulus see modulus of elasticityshear strain see strainshear stress
10、 see stressstatic fatigue strength see creep rupture strengthstrain gauge fatigue life see fatigue lifestress-rupture strength see creep rupture strengthtangent modulus see modulus of elasticitytensile stress see stresstorsional modulus see modulus of elasticitytorsional stress see stresstransverse
11、strain see straintrue strain see straintrue stress see stressultimate tensile strength (UTS) see tensile strengthyield strength see also upper yield strength and loweryield strength4. Terminology4.1 Terms and Definitions:1This terminology is under the jurisdiction of ASTM Committee E28 onMechanical
12、Testing and is the direct responsibility of Subcommittee E28.91 onTerminology except where designated otherwise. A subcommittee designation inparentheses following a definition indicates the subcommittee with responsibility forthat definition.Current edition approved Dec. 1, 2015. Published March 20
13、16. Originallyapproved in 1923. Last previous edition approved in 2009 as E6 09b1. DOI:10.1520/E0006-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standard
14、s Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.5Available from Nati
15、onal Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1accuracy, nthe permissible variation from the correct value.(
16、E28.01)alignment, nthe condition of a testing machine and loadtrain (including the test specimen) that influences the intro-duction of bending moments into a specimen during tensileloading. (E28.04)angle of bend, nthe change in the angle between the two legsof the specimen during a bend test, measur
17、ed before releaseof the bending forces.DISCUSSIONThe angle of bend is measured before release of thebending force, unless otherwise specified. (E28.02)angle of twist (torsion test), nthe angle of relative rotationmeasured in a plane normal to the torsion specimenslongitudinal axis over the gauge len
18、gth. (E28.04)bearing area L2, nthe product of the pin diameter andspecimen thickness. (E28.04)bearing force F, na compressive force on an interface.(E28.04)bearing strain, nthe ratio of the bearing deformation of thebearing hole, in the direction of the applied force, to the pindiameter. (E28.04)bea
19、ring strength FL2 , nthe maximum bearing stresswhich a material is capable of sustaining. (E28.04)bearing stress FL2 , nthe force per unit of bearing area.(E28.04)bearing yield strength FL2, nthe bearing stress at whicha material exhibits a specified limiting deviation from theproportionality of bea
20、ring stress to bearing strain. (E28.04)bend test, na test for ductility performed by bending orfolding a specimen, usually by steadily applied forces but insome instances by blows.DISCUSSIONThe bending may be interrupted to examine the bentsurface for cracks.DISCUSSIONThe ductility is usually judged
21、 by whether or not thespecimen cracks under the specified conditions of the test.DISCUSSIONThere are four general types of bend tests according tothe manner in which the forces are applied to the specimen to make thebend. These are as follows:1. Free Bend2. Guided Bend3. Semi-Guided Bend4. Wrap-Arou
22、nd BendDISCUSSIONThe specimen has a substantially uniform cross-sectionand a length several times as great as the largest dimension of thecross-section. (E28.02)bias, statistical, na constant or systematic error in testresults. (E28.04)biaxial stretching, na mode of sheet metal forming in whichposit
23、ive strains are observed in all directions at a givenlocation. (E28.02)breaking forceF, nthe force at which fracture occurs.DISCUSSIONWhen used in connection with tension tests of thinmaterials or materials of small diameter for which it is often difficult todistinguish between the breaking force an
24、d the maximum forcedeveloped, the latter is considered to be the breaking force. (E28.04)Brinell hardness number,HB , na number, which is propor-tional to the quotient obtained by dividing the test force bythe curved surface area of the indentation which is assumedto be spherical and of the diameter
25、 of the ball. (E28.06)Brinell hardness scalea designation that identifies thespecific combination of ball diameter and applied force usedto perform the Brinell hardness test. (E28.06)Brinell hardness test, ntest in which an indenter (tungstencarbide ball) is forced into the surface of a test piece a
26、nd thediameter of the indentation left in the surface after removalof the test force is measured.DISCUSSIONThe tungsten carbide ball may be used for materialswith Brinell hardness not exceeding 650. (E28.06)calibration, na process that establishes, under specificconditions, the relationship between
27、values indicated by ameasuring system and the corresponding values indicated byone or more standards.DISCUSSIONThis definition is intended to meet the principles of thedefinition of calibration provided by the ISO/IEC Guide 99:2007International Vocabulary of Basic and General Terms in Metrology(VIM)
28、. (E28.91)calibration factor, nthe factor by which a change in exten-someter reading must be multiplied to obtain the equivalentstrain.DISCUSSIONFor any extensometer, the calibration factor is equal tothe ratio of change in length to the product of the gauge length and thechange in extensometer read
29、ing. For direct-reading extensometers thecalibration factor is unity. (E28.01)compressive strength FL2, nthe maximum compressivestress that a material is capable of sustaining.DISCUSSIONCompressive strength is calculated by dividing themaximum force during a compression test by the original cross-se
30、ctional area of the specimen.DISCUSSIONIn the case of a material which fails in compression bya shattering fracture, the compressive strength has a very definite value.In the case of materials which do not fail in compression by a shatteringfracture, the value obtained for compressive strength is an
31、 arbitraryvalue depending upon the degree of distortion which is regarded asindicating complete failure of the material. (E28.04)compressometer, na specialized extensometer used for sens-ing negative or compressive strain. (E28.01)constraint, nany restriction to the deformation of a body.(E28.11)cre
32、ep, nthe time-dependent strain that occurs after theapplication of a force which is thereafter maintained con-stant.DISCUSSIONCreep tests are usually made at constant force andtemperature. For tests on plastics, the initial strain however definedis included; for tests on metals, the initial strain i
33、s not included.(E28.04)E6152creep recovery, nthe time-dependent decrease in strain in asolid, following the removal of force.DISCUSSIONRecovery is usually determined at constant tempera-ture.DISCUSSIONIn tests of plastics, the initial recovery is generallyincluded; for metals, it is not. Thermal exp
34、ansion is excluded.(E28.04)creep rupture strength FL2, nthe stress causing fracturein a creep test at a given time, in a specified constantenvironment.DISCUSSIONThis is sometimes referred to as the stress-rupturestrength or, in glass technology, the static fatigue strength. (E28.04)creep strength FL
35、2 , nthe stress that causes a given creepin a creep test at a given time in a specified constantenvironment. (E28.04)deep drawing, na metal sheet forming operation in whichstrains on the sheet surface are positive in the direction of thepunch travel and negative at 90 to that direction. (E28.02)defl
36、ectometer, na specialized extensometer used for sensingof extension or motion, usually without reference to aspecific gauge length. (E28.01)Demeri split-ring test, na test that measures the springbackbehavior of sheet metal by comparing the diameter of a ringextracted from the wall of a flat bottom
37、cup and the diameterof the same ring split to release residual stresses. (E28.02)discontinuous yielding, nin a uniaxial test, a hesitation orfluctuation of force observed at the onset of plasticdeformation, due to localized yielding.DISCUSSIONThe stress-strain curve need not appear to be discon-tinu
38、ous. (E28.04)discontinuous yielding stress, i, nthe peak stress at theinitiation of the first measurable serration on the curve ofstress-versus-strain. (E28.04)ductility, nthe ability of a material to deform plasticallybefore fracturing.DISCUSSIONDuctility is usually evaluated by measuring (1) theel
39、ongation or reduction of area from a tension test, (2) the depth of cupfrom a cupping test, (3) the radius or angle of bend from the bend test,or (4) the fatigue ductility from the fatigue ductility test (see TestMethod E796).DISCUSSIONMalleability is the ability to deform plastically underrepetitiv
40、e compressive forces. (E28.02)dynamic mechanical measurement, na technique in whicheither the modulus or damping, or both, of a substance underoscillatory applied force or displacement is measured as afunction of temperature, frequency, or time, or a combina-tion thereof. (E28.04)eccentricity, nthe
41、distance between the line of action of theapplied force and the axis of symmetry of the specimen in aplane perpendicular to the longitudinal axis of the specimen.(E28.04)edge distance L, nthe distance from the edge of a bearingspecimen to the center of the hole in the direction of appliedforce. (E28
42、.04)edge distance ratio, nthe ratio of the edge distance to the pindiameter. (E28.04)elastic calibration device, na device for use in verifying theforce readings of a testing machine consisting of an elasticmember(s) to which forces may be applied, combined with amechanism or device for indicating t
43、he magnitude (or aquantity proportional to the magnitude) of deformationunder force. (E28.01)elastic force-measuring instrumenta device or systemconsisting of an elastic member combined with a device forindicating the magnitude (or a quantity proportional to themagnitude) of deformation of the membe
44、r under an appliedforce. (E28.01)elastic limit FL2, nthe greatest stress which a material iscapable of 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 smal
45、l force, rather thanzero force, are usually taken as the initial and final reference.elongation, El, nthe increase in gauge length of a bodysubjected to a tension force, referenced to a gauge length onthe body. Usually elongation is expressed as a percentage ofthe original gauge length.DISCUSSIONThe
46、 increase in gauge length may be determined eitherat or after fracture, as specified for the material under test.DISCUSSIONThe term elongation, when applied to metals, generallymeans measurement after fracture; when applied to plastics andelastomers, measurement at fracture. Such interpretation is u
47、suallyapplicable to values of elongation reported in the literature when nofurther qualification is given.DISCUSSIONIn reporting values of elongation, the gauge length shallbe stated.DISCUSSIONElongation is affected by specimen geometry (area andshape of cross section, parallel length, parallelism,
48、fillet radii, etc.),preparation (degree to which surfaces within the reduced section aresmooth and free of cold work), and test procedure (alignment and testspeed, for example). (E28.04)elongation after fracture, nthe elongation measured byfitting the two halves of the broken specimen together.(E28.
49、04)elongation at fracture, nthe elongation measured just priorto the sudden decrease in force associated with fracture.(E28.04)error, nfor a measurement or reading, the amount it deviatesfrom a known or reference value represented by a measure-ment standard. Mathematically, the error is calculated bysubtracting the accepted value from the measurement orreading. (See also percent error.) (E28.91)expanded uncertaintya statistical measurement of the prob-able limits of error of a
