ASTM_D_5528_-_13.pdf

Designation:D552813Standard Test Method forMode I Interlaminar Fracture Toughness of UnidirectionalFiber-Reinforced Polymer Matrix Composites1This standard is issued under the fixed designation D5528;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 determination of theopening Mode I interlaminar fracture toughness,GIc,of con-tinuous fiber-reinforced composite materials using the doublecantilever beam(DCB)specimen(Fig.1).1.2 This test method is limited to use with compositesconsisting of unidirectional carbon fiber and glass fiber tapelaminates with brittle and tough single-phase polymer matri-ces.This limited scope reflects the experience gained inround-robin testing.This test method may prove useful forother types and classes of composite materials;however,certain interferences have been noted(see 6.5).1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 This standard may involve hazardous materials,operations,and equipment.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:2D883 Terminology Relating to PlasticsD2651 Guide for Preparation of Metal Surfaces forAdhesiveBondingD2734 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 MaterialsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE122 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 StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1309 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 Terminology D3878 defines terms relating to high-modulus fibers and their composites.Terminology D883 de-fines terms relating to plastics.Terminology E6 defines termsrelating to mechanical testing.Terminology E456 and PracticeE177 define terms relating to statistics.In the event of conflictbetween terms,Terminology D3878 shall have precedenceover the other terminology standards.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,u for thermodynamic temperature,and nd for non-dimensional 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.3.2 Definitions of Terms Specific to This Standard:3.2.1 crack opening mode(Mode I)fracture mode inwhich the delamination faces open away from each other.3.2.2 Mode I interlaminar fracture toughness,GIcM/T2the critical value of G for delamination growth as a result of anopening load or displacement.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.06 onInterlaminar Properties.Current edition approved Oct.1,2013.Published November 2013.Originallyapproved in 1994.Last previous edition approved in 2009 as D5528 01(2007)3.DOI:10.1520/D5528-13.2For 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 3.2.3 strain energy release rate,G M/T2the loss ofenergy,dU,in the test specimen per unit of specimen width foran infinitesimal increase in delamination length,da,for adelamination growing self-similarly under a constant displace-ment.In mathematical form,G 5 21bdUda(1)where:U=total elastic energy in the test specimen