ASTM_E_2769_-_15.pdf

Designation:E276915Standard Test Method forElastic Modulus by Thermomechanical Analysis UsingThree-Point Bending and Controlled Rate of Loading1This standard is issued under the fixed designation E2769;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.Scope1.1 This test method describes the use of linear controlled-rate-of-loading in three-point bending to determine the elasticmodulus of isotropic specimens in the form of rectangular barsusing a thermomechanical analyzer(TMA).NOTE1This method is intended to provide results similar to those ofTest Methods D790 or D5934 but is performed on a thermomechanicalanalyzer using smaller test specimens.Until the user demonstratesequivalence,the results of this method shall be considered independentand unrelated to those of Test Methods D790 or D5934.1.2 This test method provides a means for determining theelastic modulus within the linear region of the stress-straincurves(see Fig.1).This test is conducted under isothermaltemperature conditions from 100 to 300C.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 There is no ISO standard equivalent to this test method.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD790 Test Methods for Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-alsD5934 Test Method for Determination of Modulus of Elas-ticity for Rigid and Semi-Rigid Plastic Specimens byControlled Rate of Loading Using Three-Point Bending(Withdrawn 2009)3E473 Terminology Relating to Thermal Analysis and Rhe-ologyE1142 Terminology Relating to Thermophysical PropertiesE1363 Test Method for Temperature Calibration of Thermo-mechanical AnalyzersE2113 Test Method for Length Change Calibration of Ther-momechanical AnalyzersE2206 Test Method for Force Calibration of Thermome-chanical Analyzers3.Terminology3.1 DefinitionsDefinitions of technical terms used in thisstandard are defined in Terminologies E473 and E1142 includ-ing anisotropic,Celsius,expansivity,isotropic,proportionallimit,storage modulus,strain,stress,thermodilatometry,ther-momechanical analysis,and yield point.3.2 Definitions of Terms Specific to This Standard:3.2.1 elastic modulus,nthe ratio of stress to correspond-ing strain within the elastic limit on the stress-strain curve(seeFig.1)expressed in Pascal units.4.Summary of Test Method4.1 A specimen of rectangular cross section is tested inthree-point bending(flexure)as a beam.The beam rests on twosupports and is loaded midway between the supports by meansof a loading nose.A linearly increasing load(stress)is appliedto the test specimen of known geometry while the resultingdeflection(strain)is measured under isothermal conditions.The elastic modulus is obtained from the linear portion of thedisplay of resultant strain versus applied stress.5.Significance and Use5.1 This test method provides a means of characterizing themechanical behavior of materials using very small amounts ofmaterial.5.2 The data obtained may be used for quality control,research and development and establishment of optimum1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.10 onFundamental,Statistical and Mechanical Properties.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 2011.Last previous version approved in 2013 as E2769 13.DOI:10.1520/E2769-15.2For 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 standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 processing conditions.The data are not intended for use indesign or predicting performance.NOTE2This test method may not be suitable for anisotropic materials.6.Interferences6.1 Since small test specimen geometries are used,it isessential that the specimens be representative of the materialbeing tested.6.2 This test method is not applicable for strains greater than3%.7.Apparatus7.1 The function of the apparatus is to hold a rectangulartest specimen(beam)so that the material acts as the elastic anddissipative element in a mech