1、Designation: D5961/D5961M 17Standard Test Method forBearing Response of Polymer Matrix Composite Laminates1This standard is issued under the fixed designation D5961/D5961M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year o
2、f 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 covers the bearing response of pinnedor fastened joints using multi-directional polymer matrixcompo
3、site laminates reinforced by high-modulus fibers bydouble-shear tensile loading (ProcedureA), single-shear tensileor compressive loading of a two-piece specimen (ProcedureB), single-shear tensile loading of a one-piece specimen(Procedure C), or double-shear compressive loading (Proce-dure D). Standa
4、rd specimen configurations using fixed valuesof test parameters are described for each procedure. However,when fully documented in the test report, a number of testparameters may be optionally varied. The composite materialforms are limited to continuous-fiber or discontinuous-fiber(tape or fabric,
5、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 8.2.1.1.2 This test method is consistent with the recommendationsof MIL-HDBK-17, which describes the desirable at
6、tributes ofa bearing response test method.1.3 The multi-fastener test configurations described in thistest method are similar to those used by industry to investigatethe bypass portion of the bearing bypass interaction responsefor bolted joints, where the specimen may produce either abearing failure
7、 mode or a bypass failure mode. Note that thescope of this test method is limited to bearing and fastenerfailure modes. Use Test Method D7248/D7248M for by-passtesting.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach syst
8、em 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 th
9、esafety 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.1.6 This international standard was developed in accor-dance with inte
10、rnationally 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
11、 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD953 Test Method for Bearing Strength of PlasticsD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD2734 Test Methods for Void Content of Reinforced PlasticsD
12、3171 Test Methods for Constituent Content of CompositeMaterialsD3410/D3410M Test Method for Compressive Properties ofPolymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties an
13、d Equilibrium Conditioning of Polymer MatrixComposite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionD7248/D7248M Test Method for Bearing/Bypass Interac-tion Response of Polymer Matrix Composite LaminatesUsing 2-Fastener Specim
14、ensE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter Systems1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct respons
15、ibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved Aug. 1, 2017. Published September 2017. Originallyapproved in 1996. Last previous edition approved in 2013 as D5961/D5961M 13.DOI: 10.1520/D5961_D5961M-17.2For referenced ASTM standards, visit the ASTM website, www.ast
16、m.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 intern
17、ational 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) Comm
18、ittee.1E122 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 MethodsE238 Test Method for Pin-Type Bearing Test of MetallicMaterialsE456 Terminology Relating
19、to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in Databases (With-drawn 2015)3E1434 Guide for Recording Mechanical Test Data of Fiber-Reinfor
20、ced Composite Materials in Databases (Withdrawn2015)3E1471 Guide for Identification of Fibers, Fillers, and CoreMaterials in Computerized Material Property Databases(Withdrawn 2015)32.2 Other Document:MIL-HDBK-17, Polymer Matrix Composites, Vol 1, Sec-tion 743. Terminology3.1 DefinitionsTerminology
21、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, Ter
22、minology D3878 shall haveprecedence over the other documents.NOTE 1If 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,
23、shown within square brackets: Mfor mass, L for length, T for time, 1 for thermodynamic temperature,and nd for nondimensional 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.
24、3.2 Definitions of Terms Specific to This Standard:3.2.1 bearing area, L2, nthe area of that portion of abearing specimen used to normalize applied loading into aneffective bearing stress; equal to the diameter of the loadedhole multiplied by the thickness of the specimen.3.2.2 bearing chord stiffne
25、ss, EbrML-1T-2,nthe chordstiffness between two specific bearing stress or bearing strainpoints in the linear portion of the bearing stress/bearing straincurve.3.2.3 bearing force, P MLT2, nthe total force carried bya bearing specimen.3.2.4 bearing strain, ,brnd, nthe normalized holedeformation in a
26、bearing specimen, equal to the deformation ofthe bearing hole in the direction of the bearing force, dividedby the diameter of the hole.3.2.5 bearing strength, FxbrML-1T-2, nthe value ofbearing stress occurring at a significant event on the bearingstress/bearing strain curve.3.2.5.1 DiscussionTwo ty
27、pes of bearing strengths arecommonly identified, and noted by an additional superscript:offset strength and ultimate strength.3.2.6 bearing stress, FbrML-1T-2,nthe bearing forcedivided by the bearing area.3.2.7 countersink depth to thickness ratio, dcsk/h nd,theratio of the countersunk depth of a ho
28、le to the specimenthickness.3.2.7.1 DiscussionThe countersink depth to thickness ra-tio is typically a nominal value determined from nominalhole-drilling dimensions and tolerances.3.2.8 diameter to thickness ratio, D/h nd, nin a bearingspecimen, the ratio of the hole diameter to the specimenthicknes
29、s.3.2.8.1 DiscussionThe diameter to thickness ratio may beeither a nominal value determined from nominal dimensions oran actual value determined from measured dimensions.3.2.9 edge distance ratio, e/D nd, nin a bearingspecimen, the ratio of the distance between the center of thehole and the specimen
30、 end to the hole diameter.3.2.9.1 DiscussionThe edge distance ratio may be either anominal value determined from nominal dimensions or anactual value determined from measured dimensions.3.2.10 nominal value, na value, existing in name only,assigned to a measurable quantity for the purpose of conve-n
31、ient designation. Tolerances may be applied to a nominalvalue to define an acceptable range for the quantity.3.2.11 offset bearing strength, FxbroML-1T-2, nthe valueof bearing stress, in the direction specified by the subscript, atthe point where a bearing chord stiffness line, offset along thebeari
32、ng strain axis by a specified bearing strain value, inter-sects the bearing stress/bearing strain curve.3.2.11.1 DiscussionUnless otherwise specified, an offsetbearing strain of 2 % is to be used in this test method.3.2.12 width to diameter ratio, w/D nd, nin a bearingspecimen, the ratio of specimen
33、 width to hole diameter.3.2.12.1 DiscussionThe width to diameter ratio may beeither a nominal value determined from nominal dimensions oran actual value, determined as the ratio of the actual specimenwidth to the actual hole diameter.3.2.13 ultimate bearing strength, FxbruML-1T-2, nthevalue of beari
34、ng stress, in the direction specified by thesubscript, at the maximum force capability of a bearingspecimen.3.3 Symbols:A = minimum cross-sectional area of a specimenCV = coefficient of variation statistic of a sample populationfor a given property (in percent)d = fastener or pin diameterD = specime
35、n hole diameterdcsk= countersink depth3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.D5961/D5961M 172dfl= cou
36、ntersink flushness (depth or protrusion of the fas-tener in a countersunk hole)e = distance, parallel to force, from hole center to end ofspecimen; the edge distanceExbr= bearing chord stiffness in the test direction specifiedby the subscript (for determination of offset bearing strength)f = distanc
37、e, parallel to force, from hole edge to end ofspecimenFxbru= ultimate bearing strength in the test direction speci-fied by the subscriptFxbro(e %) = offset bearing strength (at e % bearing strainoffset) in the test direction specified by the subscriptg = distance, perpendicular to force, from hole e
38、dge toshortest edge of specimenh = specimen thicknessk = calculation factor used in bearing equations to distin-guish single-fastener tests from double-fastener testsK = calculation factor used in bearing equations to distin-guish hole deformation in one member of the assembly fromhole deformation s
39、hared between two members of the assem-bly in a strain equationLg= extensometer gage lengthn = number of specimens per sample populationP = force carried by test specimenPf= force carried by test specimen at failurePmax= maximum force carried by test specimen prior tofailuresn-1= standard deviation
40、statistic of a sample population fora given propertyw = specimen widthxi= test result for an individual specimen from the samplepopulation for a given propertyx = mean or average (estimate of mean) of a sample popu-lation for a given property = extensional displacement = general symbol for strain, w
41、hether normal strain or shearstrainbr= bearing strainbr= bearing stress4. Summary of Test Method4.1 Procedure A, Double Shear, Tension:4.1.1 Aflat, constant rectangular cross-section test specimenwith a centerline hole located near the end of the specimen, asshown in the test specimen drawings of Fi
42、gs. 1 and 2, is loadedat the hole in bearing. The bearing force is normally appliedthrough a close-tolerance, lightly torqued fastener (or pin) thatis reacted in double shear by a fixture similar to that shown inFigs. 3 and 4. The bearing force is created by loading theassembly in tension in a testi
43、ng machine.4.1.2 Both the applied force and the associated deformationof the hole are monitored. The hole deformation is normalizedby the hole diameter to create an effective bearing strain.Likewise, the applied force is normalized by the projected holearea to create an effective bearing stress. The
44、 specimen isloaded until a maximum force has clearly been reached,whereupon the test is terminated so as to prevent masking ofthe true failure mode by large-scale hole distortion, in order toprovide a more representative failure mode assessment. Bear-ing stress versus bearing strain for the entire l
45、oading regime isplotted, and failure mode noted. The ultimate bearing strengthof the material is determined from the maximum force carriedprior to test termination.4.1.3 The standard test configuration for this procedure doesnot allow any variation of the major test parameters. However,the following
46、 variations in specimen and test fixture configu-ration are allowed, but can be considered as being in accor-dance with this test method only as long as the values of allvariant test parameters are prominently documented with theresults:Parameter Standard VariationLoading condition: double-shear non
47、eMating material: steel fixture noneNumber of holes: 1 noneCountersink: none noneFit: tight any, if documentedFastener torque: 2.2-3.4 Nm 20-30 lbf-in. any, if documentedLaminate: quasi-isotropic any, if documentedFastener diameter: 6 mm 0.250 in. any, if documentedEdge distance ratio: 3 any, if doc
48、umentedw/D ratio: 6 any, if documentedD/h ratio: 1.53 any, if documented4.2 Procedure B, Single Shear, Two-Piece Specimen:4.2.1 The flat, constant rectangular cross-section test speci-men is composed of two like halves fastened together throughone or two centerline holes located near one end of each
49、 half,as shown in the test specimen drawings of Figs. 5-8. Theeccentricity in applied force that would otherwise result isminimized by a doubler bonded to, or frictionally retainedagainst each grip end of the specimen, resulting in a forceline-of-action along the interface between the specimen halves,through the centerline of the hole(s).4.2.1.1 Unstabilized Configuration (No Support Fixture)The ends of the test specimen are gripped in the jaws of a testmachine and loaded in tension.4.2.1.2 Stabilized Configuration
