ASTM_E_1012_-_14.pdf

Designation:E101214Standard Practice forVerification of Testing Frame and Specimen AlignmentUnder Tensile and Compressive Axial Force Application1This standard is issued under the fixed designation E1012;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 Included in this practice are methods covering thedetermination of the amount of bending that occurs during theapplication of tensile and compressive forces to notched andunnotched test specimens during routine testing in the elasticrange.These methods are particularly applicable to the forcelevels normally used for tension testing,creep testing,anduniaxial fatigue testing.The principal objective of this practiceis to assess the amount of bending exerted upon a test specimenby the ordinary components assembled into a materials testingmachine,during routine tests.2.Referenced Documents2.1 ASTM Standards:2E6 Terminology Relating to Methods of Mechanical TestingE8 Test Methods for Tension Testing of Metallic MaterialsE9 Test Methods of Compression Testing of Metallic Mate-rials at Room TemperatureE21 Test Methods for Elevated Temperature Tension Tests ofMetallic MaterialsE83 Practice for Verification and Classification of Exten-someter SystemsE251 Test Methods for Performance Characteristics of Me-tallic Bonded Resistance Strain GagesE466 Practice for Conducting Force Controlled ConstantAmplitude Axial Fatigue Tests of Metallic MaterialsE606 Test Method for Strain-Controlled Fatigue TestingE1237 Guide for Installing Bonded Resistance Strain Gages2.2 Other Documents:VAMAS Guide 42 A Procedure for the Measurement ofMachine Alignment in Axial Testing3.Terminology3.1 Definitions of Terms Common to Mechanical Testing:3.1.1 For definitions of terms used in this practice that arecommon to mechanical testing of materials,see TerminologyE6.3.1.2 alignment,nthe condition of a testing machine thatinfluences the introduction of bending moments into a speci-men(or alignment transducer)during the application of tensileor compressive forces.3.1.3 eccentricity L,nthe distance between the line ofaction of the applied force and the axis of symmetry of thespecimen in a plane perpendicular to the longitudinal axis ofthe specimen.3.1.4 reduced section L,nsection in the central portionof the specimen which has a cross section smaller than thegripped ends.3.2 Definitions of Terms Specific to This Standard:3.2.1 axial strain,a,nthe average of the longitudinalstrains measured by strain gages at the surface on oppositesides of the longitudinal axis of symmetry of the alignmenttransducer by multiple strain-sensing devices located at thesame longitudinal position.3.2.1.1 DiscussionThis definition is only applicable to thisstandard.The term is used in other contexts elsewhere inmechanical testing.3.2.2 bending strain,b,nthe difference between the strainat the surface and the axial strain(see Fig.1).3.2.2.1 Discussionin general,the bending strain variesfrom point to point around and along the reduced section of thespecimen.Bending strain is calculated as shown in Section 10.3.2.3 component(alsoknownasforceapplicationcomponent),nany of the parts used in the attachment of theload cell or grips to the testing frame,as well as any part,including the grips used in the application of force to thestrain-gaged alignment transducer or the test specimen.3.2.4 grips,nthat part of the force application componentsthat directly attach to the strain-gage alignment transducer orthe test specimen.3.2.5 microstrain,nstrain expressed in micro-units perunit,such as micrometers/meter or microinches/in.1This practice is under the jurisdiction ofASTM Committee E28 on MechanicalTesting and is the direct responsibility of Subcommittee E28.01 on Calibration ofMechanical Testing Machines and Apparatus.Current edition approved July 1,2014.Published August 2014.Originallyapproved in 1989.Last previous edition approved in 2012 as E1012 121.DOI:10.1520/E1012-14.2For 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 standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.6 notched section L,nthe section perpendicular tothe longitudinal axis of symmetry of the specimen where thecross-sectional area is intentionally at a minimum value inorder to serve as a stress raiser.3.2.7 percent bending,PB,(also known as percent bendingstrain),nthe ratio of the bending strain to the axial strainexpressed as a percentage.3.2.8 strain-gaged alignment transducer,nthe transducerused to determi