ASTM_D_2344_-_D_2344M_-_13.pdf

Designation:D2344/D2344M13Standard Test Method forShort-Beam Strength of Polymer Matrix Composite Materialsand Their Laminates1This standard is issued under the fixed designation D2344/D2344M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript 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.Scope1.1 This test method determines the short-beam strength ofhigh-modulus fiber-reinforced composite materials.The speci-men is a short beam machined from a curved or a flat laminateup to 6.00 mm 0.25 in.thick.The beam is loaded inthree-point bending.1.2 Application of this test method is limited to continuous-or discontinuous-fiber-reinforced polymer matrix composites,for which the elastic properties are balanced and symmetricwith respect to the longitudinal axis of the beam.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem must be used independently of the other.Combiningvalues from the two systems may result in nonconformancewith the standard.1.4 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:2D792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD2734 Test Methods for Void Content of Reinforced PlasticsD3171 Test Methods for Constituent Content of CompositeMaterialsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE1309 GuideforIdentificationofFiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE1471 Guide for Identification of Fibers,Fillers,and CoreMaterials in Computerized Material Property Databases3.Terminology3.1 DefinitionsTerminology D3878 defines the terms re-lating to high-modulus fibers and their composites.Terminol-ogy D883 defines terms relating to plastics.Terminology E6defines terms relating to mechanical testing.Terminology E456and Practice E177 define terms relating to statistics.In theevent of a conflict between definitions,Terminology D3878shall have precedence over the other documents.NOTE1If the term represents a physical quantity,its analyticaldimensions are stated immediately following the term(or letter symbol)infundamental dimension form,using the following ASTM standard sym-bology for fundamental dimensions,shown within square brackets:Mfor mass,L for length,T for time,for thermodynamic temperature,and nd for nondimensional quantities.Use of these symbols is restrictedto analytical dimensions when used with square brackets,as the symbolsmay have other definitions when used without the brackets.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.04 onLamina and Laminate Test Methods.Current edition approved Oct.1,2013.Published December 2013.Originallyapproved in 1965.Last previous edition approved in 2006 as D2344 00R06.DOI:10.1520/D2344_D2344M-13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2 Definitions of Terms Specific to This Standard:3.2.1 balanced laminate,na continuous fiber-reinforcedlaminate in which each+lamina,measured with respect to thelaminate reference axis,is balanced by a lamina of the samematerial(for example,0/+45/45/+45/45/0).3.2.2 short-beam strength,nthe shear stress as calculatedin Eq 1,developed at the specimen mid-plane at t