ASTM_D_695_-_15.pdf

Designation:D69515Standard Test Method forCompressive Properties of Rigid Plastics1This standard is issued under the fixed designation D695;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test method covers the determination of the me-chanical properties of unreinforced and reinforced rigidplastics,including high-modulus composites,when loaded incompression at relatively low uniform rates of straining orloading.Test specimens of standard shape are employed.Thisprocedure is applicable for a composite modulus up to andincluding 41,370 MPa(6,000,000 psi).1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.NOTE1For compressive properties of resin-matrix composites rein-forcedwithorientedcontinuous,discontinuous,orcross-plyreinforcements,tests may be made in accordance with Test MethodD3410/D3410M or D6641/D6641M.1.3 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.A specific precau-tionary statement is given in 13.1.NOTE2This standard is equivalent to ISO 604.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsD3410/D3410M Test Method for Compressive Properties ofPolymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD4000 Classification System for Specifying Plastic Materi-alsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD6641/D6641M Test Method for Compressive Properties ofPolymer Matrix Composite Materials Using a CombinedLoading Compression(CLC)Test FixtureE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exten-someter SystemsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:3ISO 604 PlasticsDetermination of Compressive Properties3.Terminology3.1 GeneralThe definitions of plastics used in this testmethod are in accordance with Terminology D883 unlessotherwise indicated.3.2 Definitions:3.2.1 compressive deformationthe decrease in length pro-duced in the gage length of the test specimen by a compressiveload.It is expressed in units of length.3.2.2 compressive strainthe ratio of compressive defor-mation to the gage length of the test specimen,that is,thechange in length per unit of original length along the longitu-dinal axis.It is expressed as a dimensionless ratio.3.2.3 compressive strengththe maximum compressivestress(nominal)carried by a test specimen during a compres-sion test.It may or may not be the compressive stress(nominal)carried by the specimen at the moment of rupture.3.2.4 compressive strength at failure(nominal)the com-pressive stress(nominal)sustained at the moment of failure ofthe test specimen if shattering occurs.3.2.5 compressive stress(nominal)the compressive loadper unit area of minimum original cross section within the gageboundaries,carried by the test specimen at any given moment.It is expressed in force per unit area.3.2.5.1 DiscussionThe expression of compressive proper-ties in terms of the minimum original cross section is almost1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved Sept.1,2015.Published September 2015.Originallyapproved in 1942.Last previous edition approved in 2010 as D695-10.DOI:10.1520/D0695-15.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*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 universally used.Under some circumstances the compressiveproperties have been expressed per unit of prevailing crosssection.These properties are called“true”compressive prop-erties.3.2.6 compressive stress-strain diagrama diagram inwhich values of compressive stress are plotted as ordinatesagainst corresponding values of compressive strain as abscis-sas.3.2.7 compressive yield pointthe first point on the