FASTENER TEST METHODS, METHOD 21, SHEAR JOINT FATI

MlL-STD-1312-2126JULY1985SUPERSEDINGMIL-STD-1312(inpart)31MAY1967MILITARYSTANDARDFASTENERTESTMETHODSMETHOD21,SHEARJOINTFATIGUEFSC53GPDISTRIBUTIONSTATEMENTA:Approvedforpublicrelease;distributionisunlimited.Downloadedfrom:00.MIL-STD-1312-21DEPARTMENTOFDEFENSEWASHINGTON,DC20301FastenerTestMethods,Method21,ShearJointFatigue-ConstantAmplitudeMIL-STD-1312-21andany1.ThisMilitaryStandardisapprovedforusebyallDepartmentsAgenciesoftheDepartmentofDefense.2.Beneficialcomments(recommendations,additions,deletions)andpertinentdatawhichmaybeofuseinimprovingthisdocumentshouldbeaddressedto:CommandingOfficer,NavalAirEngineeringCenter,SystemsEngineeringandStandardizationDepartment(SESD),Code93,Lakehurst,NJ08733,byusingtheself-addressedStandardizationDocumentImprovementProposal(DDForm1426)appearingattheendofthisdocumentorbyletter.iiDownloadedfrom:00.MIL-STD-1312-21FOREWORDThisstandardsetsforthastandardtestprocedurefordeterminingtheshearjointfatigueoffastenersatroomtemperature.iiiDownloadedfrom:00.ParagraphMIL-STD-1312-21TABLEOFCONTENTS1.1.12.2.12.1.12.23.4.4.14.1.14.1.1.14.1.1.1.14.1.24.1.2.14.1.2.1.34.1.2.34.1.2.44.1.34.24.2.24.2.34.2.44.2.54.2.5.14.2.5.24.2.5.34.2.5.44.2.64.2.6.14.2.6.24.2.6.35.5.15.1.15.1.25.1.2.15.1.2.25.1.2.35.1.2.45.1.2.55.1.2.65.1.2.7SCOPE................................Applicability...........................REFERENCEDDOCUMENTS.......................Governmentdocuments....................Specifications,standardsandhandbooks.........Otherpublications......................DEFINITIONS............................2GENEFUILREQUIREMENTS.....................2Testapparatus.........................Fatiguetestmachineloadingsystem...............Calibration...........................Elasticcalibration.....................Staticalignment.......................Equipment...........................Alignmentcells........................Procedure...........................Alignmentexample......................Fixtures............................Testspecimens........................Methodofloading........................7Preparation..........................7Stripmaterialmechanicalproperties..........12Fastenerholes........................12Holediameter.........................12Countersunkfastenerholes..................12Protrudingfastenerholes.................12Fastenerorientation....................12Assembly............................12Fastenerinstallation.....................12Sheetgap............................13Fastenerheadseating....................13DETAILREQUIREMENTS......................13Testprocedures........................Installation.........................Testconditions.......................Jointstaticstrength....................Loadlevel...........................Fatiguetesttype.......................Loadratio...........................Testspeed...........................Specimenrestraints.....................Failure.............................ivPage1111112222555557713131313131313131316Downloadedfrom:00.MIL-STD-1312-21TABLEOFCONTENTS(Continued)6.6.16.21.2.3.4.5.6.7.8.9.NOTES16..................................Testreport.........................16Preparationofdata....................17ElasticTypicalTypicalTypicalFIGUREScalibrationdevices..............loadcellcircuits...............equipmentusedforcheckingalignment...alignmentcells.................Lapjointspecimen-singleshear100%loadtransfer...............................Specimendetail,lowloadtransfertestspecimenjoint..........................Specimendetail,noloadtransfertestspecimenjoint.........................Specimenrestraintfixture(flexurepivot/90°offset).............................Specimenrestraintfixture(sandwichtype)....vPage3468910111415FigureDownloadedfrom:00.Downloadedfrom:00.MIL-STD-1312-211.SCOPE1.1Applicability.Thistestmethodcoverstheprocedureandapparatusrequiredfortestingtheshearjointfatigueoffastenersatroomtemperature.2.REFERENCEDDOCUMENTS2.1Governmentdocuments.2.1.1Specifications,standardsandhandbooks.Unlessotherwisespecified,thefollowingspecifications,standardsandhandbooksoftheissuelistedinthecurrentDepartmentofDefenseIndexofSpecifi-cationsandStandards(DoDISS)andthesupplementthereto(ifapplicable),formapartofthisstandardtotheextentspecifiedherein.SPECIFICATIONS‘FEDERALQQ-A-250/5TT-P-1757AluminumAlloyAlclad2024,PlateandSheetPrimerCoating,ZincChromate,LowMoistureSensitivityMILITARYMIL-P-6808PrimerCoating,ZincChromate,ProcessforApplicationofMIL-T-9046TitaniumandTitaniumAlloy,Sheet,StripandPlate(Copiesofspecifications,standards,handbooks,drawingsandpublicationsrequiredbycontractorsinconnectionwithspecificacquisi-tionfunctionsshouldbeobtainedfromthecontractingactivityorasdirectedbythecontractingofficer.)2.2Otherpublications.Thefollowingdocument(s)formsapartofthisspecificationtotheextentspecifi