1、Designation: D 5961/D 5961M 05e1Standard Test Method forBearing Response of Polymer Matrix Composite Laminates1This standard is issued under the fixed designation D 5961/D 5961M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe units of measurement in the last sentence of 7.1 were corrected editorially in April 2007.1. Scope1.1 This test
3、 method covers the bearing response of multi-directional polymer matrix composite laminates reinforced byhigh-modulus fibers by either double-shear (Procedure A)tensile loading or single-shear (Procedure B) tensile or com-pressive loading of a specimen. Standard specimen configura-tions using fixed
4、values of test parameters are described foreach procedure. However, when fully documented in the testreport, a number of test parameters may be optionally varied.The composite material forms are limited to continuous-fiberor discontinuous-fiber (tape or fabric, or both) reinforcedcomposites for whic
5、h the laminate is balanced and symmetricwith respect 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 response test metho
6、d.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 mode or a bypass failure mode. While th
7、is testmethod may be referenced as guidance in bearing bypass testprograms, the scope of this test method is limited to bearingfailure modes.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text theinch-pound units are shown in bracket
8、s. The values stated ineach system are not exact equivalents; therefore, each systemmust be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with thestandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated
9、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:2D 792 Test Methods for Density and Specific Gravity (Rela-tive D
10、ensity) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 953 Test Method for Bearing Strength of PlasticsD 2584 Test Method for Ignition Loss of Cured ReinforcedResinsD 2734 Test Method for Void Content of Reinforced Plas-ticsD 3171 Test Method for Constituent Content of CompositeM
11、aterialsD 3878 Terminology for Composite MaterialsD 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsD 5687/D 5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionE4 Practi
12、ces for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Test-ingE83 Practice for Verification and Classification of Exten-someter SystemE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for aCharacteristic of a
13、 Lot or ProcessE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 238 Test Method for Pin-Type Bearing Test of MetallicMaterialsE 456 Terminology Relating to Quality and StatisticsE 1309 Guide for Identification of Fiber-Reinforced1This test method is under the jurisdiction
14、of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved March 1, 2005. Published March 2005. Originallyapproved in 1996. Last previous edition approved in 2001 as D 5961/D 5961M 01e1 .2For referenced ASTM
15、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
16、en, PA 19428-2959, United States.Polymer-Matrix Composite Materials in DatabasesE 1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE 1471 Guide for Identification of Fibers, Fillers, and CoreMaterials in Computerized Material Property Databases2.2 Oth
17、er Document:MIL-HDBK-17, Polymer Matrix Composites, Vol 1, Sec-tion 733. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto high-modulus fibers and their composites. TerminologyD 883 defines terms relating to plastics. Terminology E6defines terms relating to mechanical testing. Te
18、rminologyE 456 and Practice E 177 define terms relating to statistics. Inthe event of a conflict between terms, Terminology D 3878shall have precedence over the other documents.3.2 Definitions of Terms Specific to This Standard:NOTE 1If the term represents a physical quantity, its analyticaldimensio
19、ns 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, 1 for thermodynamic temperature,and nd for nondimensional quantiti
20、es. Use of these symbols is restrictedto analytical dimensions when used with square brackets, as the symbolsmay have other definitions when used without the brackets.3.3 bearing area, L2, nthe area of that portion of abearing specimen used to normalize applied loading into aneffective bearing stres
21、s; equal to the diameter of the loadedhole multiplied by the thickness of the specimen.3.4 bearing chord stiffness, EbrML-1T-2, nthe chordstiffness between two specific bearing stress or bearing strainpoints in the linear portion of the bearing stress/bearing straincurve.3.5 bearing load, P MLT2, nt
22、he total load carried by abearing specimen.3.6 bearing strain, e,brnd, nthe normalized hole defor-mation in a bearing specimen, equal to the deformation of thebearing hole in the direction of the bearing load, divided by thediameter of the hole.3.7 bearing strength, FxbrML-1T-2, nthe value of bear-i
23、ng stress occurring at a significant event on the bearingstress/bearing strain curve.3.7.1 DiscussionTwo types of bearing strengths are com-monly identified, and noted by an additional superscript: offsetstrength and ultimate strength.3.8 bearing stress, FbrML-1T-2, nthe bearing load di-vided by the
24、 bearing area.3.9 diameter to thickness ratio, D/h nd, nin a bearingspecimen, the ratio of the hole diameter to the specimenthickness.3.9.1 DiscussionThe diameter to thickness ratio may beeither a nominal value determined from nominal dimensions oran actual value determined from measured dimensions.
25、3.10 edge distance ratio, e/D nd, nin a bearing speci-men, the ratio of the distance between the center of the hole andthe specimen end to the hole diameter.3.10.1 DiscussionThe edge distance ratio may be either anominal value determined from nominal dimensions or anactual value determined from meas
26、ured dimensions.3.11 nominal value, na value, existing in name only,assigned to a measurable quantity for the purpose of conve-nient designation. Tolerances may be applied to a nominalvalue to define an acceptable range for the quantity.3.12 offset bearing strength, FxbroML-1T-2, nthe valueof bearin
27、g stress, in the direction specified by the subscript, atthe point where a bearing chord stiffness line, offset along thebearing strain axis by a specified bearing strain value, inter-sects the bearing stress/bearing strain curve.3.12.1 DiscussionUnless otherwise specified, an offsetbearing strain o
28、f 2 % is to be used in this test method.3.13 width to diameter ratio, w/D nd, nin a bearingspecimen, the ratio of specimen width to hole diameter.3.13.1 DiscussionThe width to diameter ratio may beeither a nominal value determined from nominal dimensions oran actual value, determined as the ratio of
29、 the actual specimenwidth to the actual hole diameter.3.14 ultimate bearing strength, FxbruML-1T-2, nthevalue of bearing stress, in the direction specified by thesubscript, at the maximum load capability of a bearing speci-men.3.15 Symbols:A = minimum cross-sectional area of a specimenCV = coefficie
30、nt of variation statistic of a sample populationfor a given property (in percent)d = fastener or pin diameterD = specimen hole diametere = distance, parallel to load, from hole center to end ofspecimen; the edge distanceExbr= bearing chord stiffness in the test direction specifiedby the subscriptf =
31、 distance, parallel to load, 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 load, from
32、hole edge 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 single-shear tests from double-shear tests in a singlebearing s
33、train equationLg= extensometer gage lengthn = number of specimens per sample populationP = load carried by test specimenPf= load carried by test specimen at failurePmax= maximum load carried by test specimen prior tofailure3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section
34、 D, 700 Robbins Ave., Philadelphia, PA 19111-5098.D 5961/D 5961M 05e12sn-1= standard deviation 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 sam
35、ple popu-lation for a given propertyd = extensional displacemente = general symbol for strain, whether normal strain or shearstrainebr= bearing strainsbr= bearing stressw = specimen widthdcsk= countersink depthdfl= countersink flushness (depth or protrusion of the fas-tener in a countersunk hole)4.
36、Summary of Test Method4.1 Procedure A, Double Shear: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 Figs. 1 and 2, is loadedat the hole in bearing. The bearing load is normally appliedt
37、hrough 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 load is created by pulling theassembly in tension in a testing machine.4.1.2 Both the applied load and the associated deformationof the hole are
38、monitored. The hole deformation is normalizedby the hole diameter to create an effective bearing strain.Likewise, the applied load is normalized by the projected holearea to create an effective bearing stress. The specimen isloaded until a load maximum has clearly been reached,whereupon the test is
39、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 loading regime isplotted, and failure mode noted. The ultimate bearing strengthof the mat
40、erial is determined from the maximum load carriedprior to test termination.4.1.3 The standard test configuration for this procedure doesnot allow any variation of the major test parameters. However,FIG. 1 Double-Shear Test Specimen Drawing (SI)D 5961/D 5961M 05e13the following variations in configur
41、ation are allowed, but canbe considered as being in accordance with this test method onlyas long as the values of all variant test parameters areprominently documented with the results.Parameter Standard VariationLoading condition: double-shear noneMating material: steel fixture noneNumber of holes:
42、 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 documentedw/D ratio: 6 any, if documentedD/h ratio: 1.2
43、-2 any, if documented4.2 Procedure B, Single Shear: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 half,as shown in the test specimen drawings of Figs. 5-8. Theeccentric
44、ity in applied load that would otherwise result isminimized by a doubler bonded to each grip end of thespecimen, resulting in a load line-of-action along the interfacebetween the specimen halves, through the centerline of thehole(s).4.2.1.1 Unstabilized Configuration (No Support Fixture)The ends of
45、the test specimen are gripped in the jaws of a testmachine and loaded in tension.4.2.1.2 Stabilized Configuration (Using Support Fixture)The test specimen is face-supported in a multipiece boltedsupport fixture, as shown in Fig. 9. The test specimen/fixtureassembly is clamped in hydraulic wedge grip
46、s and the load issheared into the support fixture and then sheared into thespecimen. The stabilized configuration is primarily intendedfor compressive loading, although the specimen/fixture assem-bly may be loaded in either tension or compression.4.2.2 Both the applied load and the associated deform
47、ationof the hole(s) are monitored. The deformation of the hole(s) isnormalized by the hole diameter (a factor of two used to adjustfor hole deformation occurring in the two halves) to result in aneffective bearing strain. Likewise, the applied load is normal-ized by the projected hole area to yield
48、an effective bearingFIG. 2 Double-Shear Test Specimen Drawing (Inch-Pound)D 5961/D 5961M 05e14stress. The specimen is loaded until a load maximum hasclearly been reached, whereupon the test is terminated so as toprevent masking of the true failure mode by large-scale holedistortion, in order to prov
49、ide a more representative failuremode assessment. Bearing stress versus bearing strain for theentire loading regime is plotted, and failure mode noted. Theultimate bearing strength of the material is determined from themaximum load carried prior to test termination.4.2.3 The standard test configuration for this procedure doesnot allow any variation of the major test parameters. However,the following variations in configuration are allowed, but canbe considered as being in accordance with this test method onlyas long as
