ASTM_D_7248_-_D_7248M_-_21.pdf

Designation:D7248/D7248M21Standard Test Method forHigh Bearing-Low Bypass Interaction Response ofPolymer Matrix Composite Laminates Using 2-FastenerSpecimens1This standard is issued under the fixed designation D7248/D7248M;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 uniaxial bearing/bypassinteraction response of multi-directional polymer matrix com-posite laminates reinforced by high-modulus fibers by eitherdouble-shear tensile loading(Procedure A)or single-sheartensile or compressive loading(Procedure B)of a two-fastenerspecimen.The scope of this test method is limited to netsection(bypass)failure modes.Standard specimen configura-tions using fixed values of test parameters are described foreach procedure.A number of test parameters may be variedwithin the scope of the standard,provided that the parametersare fully documented in the test report.The composite materialforms are limited to continuous-fiber or discontinuous-fiber(tape or fabric,or both)reinforced composites for which thelaminate is balanced and symmetric with respect to the testdirection.The range of acceptable test laminates and thick-nesses are described in 8.2.1.Test methods for high bypass-low bearing response of polymer matrix composite materials,previously published under Procedure C of this test method,are now published in Test Method D8387/D8387M.1.2 This test method is consistent with the recommendationsof Composite Materials Handbook,CMH-17,which describesthe desirable attributes of a bearing/bypass interaction responsetest method.1.3 The two-fastener test configurations described in thistest method are similar to those in Test Method D5961/D5961M as well as those used by industry to investigate thebearing portion of the bearing/bypass interaction response forbolted joints,where the specimen may produce either a bearingfailure mode or a bypass failure mode.Should the testspecimen fail in a bearing failure mode rather than the desiredbypass mode,then the test should be considered to be a bearingdominated bearing/bypass test,and the data reduction andreporting procedures of Test Method D5961/D5961M shouldbe used instead of those given in this test method.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 Materials1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved May 15,2021.Published June 2021.Originallyapproved in 2007.Last previous edition approved in 2017 as D7248/D7248M 12(2017).DOI:10.1520/D7248_D7248M-21.2For 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.1D56