ASTM_D_3379_-_75_1989e1.pdf

Designation:D 3379 75(Reapproved 1989)e1Standard Test Method forTensile Strength and Youngs Modulus for High-ModulusSingle-Filament Materials1This standard is issued under the fixed designation D 3379;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(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.e1NOTEEditorial changes were made throughout in May 1989.1.Scope1.1 This test method covers the preparation,mounting,andtesting of high-modulus single-filament materials over 21 3 109Pa(3 3 106psi)for the determination of tensilestrength and Youngs modulus,at room temperature.1.2 This test method is limited to single filaments utilizing afixed gage length at least 2000 times longer than the nominalfilament diameter.1.3 This standard may involve hazardous materials,opera-tions,and equipment.This standard does not purport toaddress all of the safety concerns associated with its use.It isthe responsibility of the user of this standard to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 638 Test Method for Tensile Properties of Plastics2E 4 Practices for Force Verification of Testing Machines3E 6 Terminology Relating to Methods of Mechanical Test-ing33.Terminology3.1 Definitions:3.1.1 mounting taba thin paper,compliant metal,orplastic strip with a longitudinal slot of fixed gage length.Themounting tab should be as thin as practicable to minimizefilament misalignment.3.1.2 system compliancethat portion of the indicatedelongation contributed by the load train system and thespecimen gripping system.This compliance must be deter-mined experimentally for a given combination of test machineconditions,grip system and mounted specimen.It must besubtracted from the indicated elongation to yield true specimenelongation in the gage length(Note 1).System compliancecorrection will not apply when elongation in the specimen gagelength is determined by direct measurement.NOTE1The magnitude of the system compliance can be a significantportion of the indicated compliance.Extreme care must be exercised in thedetermination of this correction as outlined in 8.2.3.2 Definitions of terms and symbols relating to this testmethod appear in Terminology E 6,and the Appendix to TestMethod D 638.4.Summary of Test Method4.1 A random selection of single filaments is made from thematerial to be tested.The filaments are center-line mounted onspecial slotted tabs.The tabs are gripped so that the testspecimen is aligned axially in the jaws of a constant-speedmovable-crosshead test machine.The filaments are thenstressed to failure at a constant strain rate.4.2 For this test method,filament cross-sectional areas aredetermined by planimeter measurements of a representativenumber of filament cross sections as displayed on highlymagnified photomicrographs.Alternative methods of area de-termination such as optical gages,image-splitting microscope,linear weight-density method,etc,may also be used.4.3 Tensile strength and Youngs modulus are calculatedfrom the load-elongation records and the cross-sectional areameasurements.5.Significance and Use5.1 Properties determined by this test method are veryuseful in the evaluation of new materials at the research anddevelopment levels.Very short filaments,such as whiskers ofnonuniform cross section,call for highly specialized testtechniques not covered by this test method.1This test method is under the jurisdiction of ASTM Committee C-28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.07 onCeramic Matrix Composites.Current edition approved Feb.28,1975.Published April 1975.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 03.01.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.Apparatus6.1 Tensile strength and Youngs modulus properties ofsingle-filament specimens may be determined by several es-tablished testing procedures.The apparatus described hereinshall use a constant-strain-rate tensile testing machine with atest specimen bonded to a suitable tab.6.2 Stationary MemberThis member shall be rigidly fixedto the test machine frame and shall contain a housing,locatedon the machine centerline,for a load cell and part of thespecimen grip assembly.6.3 Movable MemberThis member,also called the cross-head,shall be driven at a constant preset strain rate.It shallcontain an adaptor,on the machine centerline,for the other partof the specimen grip assembly.6.4 Load CellThe load-sensing device shall have suffi-cient capacity to accept and transmit load signals above thehighest anticipated loads.Its accuracy shall be verified inaccordance