ASTM_D_7248_-_D_7248M_-_12.pdf

Designation:D7248/D7248M12Standard Test Method forBearing/Bypass Interaction Response of Polymer MatrixComposite Laminates Using 2-Fastener Specimens1This 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(Procedures A and C)or single-shear tensile or compressive loading(Procedure B)of atwo-fastener specimen.The scope of this test method is limitedto net section(bypass)failure modes.Standard specimenconfigurations using fixed values of test parameters are de-scribed for each procedure.A number of test parameters maybe varied within the scope of the standard,provided that theparameters are fully documented in the test report.Thecomposite material forms are limited to continuous-fiber ordiscontinuous-fiber(tape or fabric,or both)reinforced com-posites for which the laminate is balanced and symmetric withrespect to the test direction.The range of acceptable testlaminates and thicknesses are described in 8.2.1.1.2 This test method is consistent with the recommendationsof MIL-HDBK-17,which describes the desirable attributes ofa bearing/bypass interaction response test 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 standard.1.4 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 shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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 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-tionD5766/D5766M Test Method for Open-Hole TensileStrength of Polymer Matrix Composite LaminatesD5961/D5961M Test Method for Bearing Response of Poly-mer Matrix Composite LaminatesD6484/D6484M Test Method for Open-Hole CompressiveStrength of Polymer Matrix Composite LaminatesD6742/D6742M Practice for Filled-Hole Tension and Com-pression Testing of Polymer Matrix Composite LaminatesE4 Practices for Force Verification of Testing Machines1This 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 April 1,2012.Published May 2012.Originallyapproved in 2007.Last previous edition approved in 2008 as D7248/D7248M-08.DOI:10.1520/D7248_D7248M-12.2For 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 E6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE122 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 MethodsE251 Test Methods for Pe