ASTM_D_6415_-_D_6415M_-_22.pdf

Designation:D6415/D6415M22Standard Test Method forMeasuring the Curved Beam Strength of a Fiber-ReinforcedPolymer-Matrix Composite1This standard is issued under the fixed designation D6415/D6415M;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.1.Scope1.1 This test method determines the curved beam strength ofa continuous fiber-reinforced composite material using a 90curved beam specimen(Figs.1 and 2).The curved beamconsists of two straight legs connected by a 90 bend with a6.4 mm 0.25 in.inner radius.An out-of-plane(through-the-thickness)tensile stress is produced in the curved region of thespecimen when force is applied.This test method is limited touse with composites consisting of layers of fabric or layers ofunidirectional fibers.1.2 This test method may also be used to measure theinterlaminar tensile strength if a unidirectional specimen isused where the fibers run continuously along the legs andaround the bend.1.3 This test method is limited to use with compositesconsisting of layers of fabric or layers of unidirectional fibers.1.4 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system are not necessarily exact equiva-lents;therefore,to ensure conformance with the standard,eachsystem shall be used independently of the other,and valuesfrom the two systems shall not be combined.1.4.1 Within the text,the inch-pound units are shown inbrackets.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.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 Calibration and Verification of Test-ing 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 Statistics3.Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto high-modulus fibers and their composites.TerminologyD883 defines terms relating to plastics.Terminology E6 definesterms relating to mechanical testing.Terminology E456 andPractice E177 define terms relating to statistics.In the event ofa conflict between terms,Terminology D3878 shall haveprecedence over the other terminology standards.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of D30.06 on InterlaminarProperties.Current edition approved Feb.1,2022.Published April 2022.Originallyapproved in 1999.Last previous edition approved in 2013 as D6415/D6415M 06a(2013).DOI:10.1520/D6415_D6415M-22.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.13.2 Definitions of Terms Specific to This Standard:NOTE1If the term represents a physical quantity,its analyticaldimensions are stated immediately following the term(or letter symbol)infundamental dimension form,usi