1、Designation: D5961/D5961M 10D5961/D5961M 13Standard 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 revis
2、ion, 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 covers the bearing response of pinned or fastened joints using multi-directional pol
3、ymer matrix compositelaminates reinforced by high-modulus fibers by double-shear tensile loading (Procedure A), single-shear tensile or compressiveloading of a two-piece specimen (Procedure B), single-shear tensile loading of a one-piece specimen (Procedure C), ordouble-shear compressive loading (Pr
4、ocedure D). Standard specimen configurations using fixed values of test parameters aredescribed for each procedure. However, when fully documented in the test report, a number of test parameters may be optionallyvaried. The composite material forms are limited to continuous-fiber or discontinuous-fi
5、ber (tape or fabric, or both) reinforcedcomposites for which the laminate is balanced and symmetric with 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 recommendations of MIL-HDBK-17, which descr
6、ibes the desirable attributes of abearing response test method.1.3 The multi-fastener test configurations described in this test method are similar to those used by industry to investigate thebypass portion of the bearing bypass interaction response for bolted joints, where the specimen may produce
7、either a bearing failuremode or a bypass failure mode. Note that the scope of this test method is limited to bearing and fastener failure modes. Use TestMethod D7248/D7248M for by-pass testing.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The
8、 values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.4.1 Within the text the inch-pound units are shown in brackets.1.5 This standard does not
9、 purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2
10、D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD953 Test Method for Bearing Strength of PlasticsD2584 Test Method for Ignition Loss of Cured Reinforced ResinsD2734 Test Methods for Void Content of Reinforced Plast
11、icsD3171 Test Methods for Constituent Content of Composite MaterialsD3410/D3410M Test Method for Compressive Properties of Polymer Matrix Composite Materials with Unsupported GageSection by Shear LoadingD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for Moisture Absorption Propert
12、ies and Equilibrium Conditioning of Polymer Matrix CompositeMaterialsD5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation1 This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibili
13、ty of Subcommittee D30.05 on Structural TestMethods.Current edition approved Oct. 1, 2010May 1, 2013. Published November 2010June 2013. Originally approved in 1996. Last previous edition approved in 20082010 asD5961/D5961M 08.D5961/D5961M 10. DOI: 10.1520/D5961_D5961M-10.10.1520/D5961_D5961M-13.2 Fo
14、r referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to pro
15、vide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the
16、 standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D7248/D7248M Test Method for Bearing/Bypass Interaction Response of Polymer Matrix Composite Laminates Using2-Fas
17、tener SpecimensE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Extensometer SystemsE122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Cha
18、racteristic of a Lot orProcessE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE238 Test Method for Pin-Type Bearing Test of Metallic MaterialsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision
19、of a Test MethodE1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE1471 Guide for Identification of Fibers, Fillers, and Core Materials in Computerized M
20、aterial Property Databases2.2 Other Document:MIL-HDBK-17, Polymer Matrix Composites, Vol 1, Section 733. Terminology3.1 DefinitionsTerminology D3878 defines terms relating to high-modulus fibers and their composites. Terminology D883defines terms relating to plastics. Terminology E6 defines terms re
21、lating to mechanical testing. Terminology E456 and PracticeE177 define terms relating to statistics. In the event of a conflict between terms, Terminology D3878 shall have precedence overthe other documents.NOTE 1If the term represents a physical quantity, its analytical dimensions are stated immedi
22、ately following the term (or letter symbol) infundamental dimension form, using the following ASTM standard symbology for fundamental dimensions, shown within square brackets: M for mass,L for length, T for time, 1 for thermodynamic temperature, and nd for nondimensional quantities. Use of these sym
23、bols is restricted to analyticaldimensions when used with square brackets, as the symbols may have other definitions when used without the brackets.3.2 Definitions of Terms Specific to This Standard:3.2.1 bearing area, L2, nthe area of that portion of a bearing specimen used to normalize applied loa
24、ding into an effectivebearing stress; equal to the diameter of the loaded hole multiplied by the thickness of the specimen.3.2.2 bearing chord stiffness, Ebr ML-1T-2 , nthe chord stiffness between two specific bearing stress or bearing strain pointsin the linear portion of the bearing stress/bearing
25、 strain curve.3.2.3 bearing force, P MLT2, nthe total force carried by a bearing specimen.3.2.4 bearing strain, ,br nd, nthe normalized hole deformation in a bearing specimen, equal to the deformation of thebearing hole in the direction of the bearing force, divided by the diameter of the hole.3.2.5
26、 bearing strength, Fxbr ML-1T-2, nthe value of bearing stress occurring at a significant event on the bearingstress/bearing strain curve.3.2.5.1 DiscussionTwo types of bearing strengths are commonly identified, and noted by an additional superscript: offset strength and ultimatestrength.3.2.6 bearin
27、g stress, Fbr ML-1T-2 , nthe bearing force divided by the bearing area.3.2.7 countersink depth to thickness ratio, dcsk /hnd,the ratio of the countersunk depth of a hole to the specimen thickness.3.2.7.1 DiscussionThe countersink depth to thickness ratio is typically a nominal value determined from
28、nominal hole-drilling dimensions andtolerances.3.2.8 diameter to thickness ratio, D/h nd, nin a bearing specimen, the ratio of the hole diameter to the specimen thickness.3.2.8.1 Discussion3 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelph
29、ia, PA 19111-5098, http:/dodssp.daps.dla.mil.D5961/D5961M 132The diameter to thickness ratio may be either a nominal value determined from nominal dimensions or an actual value determinedfrom measured dimensions.3.2.9 edge distance ratio, e/D nd, nin a bearing specimen, the ratio of the distance bet
30、ween the center of the hole and thespecimen end to the hole diameter.3.2.9.1 DiscussionThe edge distance ratio may be either a nominal value determined from nominal dimensions or an actual value determined frommeasured dimensions.3.2.10 nominal value, na value, existing in name only, assigned to a m
31、easurable quantity for the purpose of convenientdesignation. Tolerances may be applied to a nominal value to define an acceptable range for the quantity.3.2.11 offset bearing strength, Fxbro ML-1T-2, nthe value of bearing stress, in the direction specified by the subscript, at thepoint where a beari
32、ng chord stiffness line, offset along the bearing strain axis by a specified bearing strain value, intersects thebearing stress/bearing strain curve.3.2.11.1 DiscussionUnless otherwise specified, an offset bearing strain of 2 % is to be used in this test method.3.2.12 width to diameter ratio, w/D nd
33、, nin a bearing specimen, the ratio of specimen width to hole diameter.3.2.12.1 DiscussionThe width to diameter ratio may be either a nominal value determined from nominal dimensions or an actual value, determinedas the ratio of the actual specimen width to the actual hole diameter.3.2.13 ultimate b
34、earing strength, Fxbru ML-1T-2, nthe value of bearing stress, in the direction specified by the subscript, atthe maximum force capability of a bearing specimen.3.3 Symbols:A = minimum cross-sectional area of a specimenCV = coefficient of variation statistic of a sample population for a given propert
35、y (in percent)d = fastener or pin diameterD = specimen hole diameterdcsk = countersink depthdfl = countersink flushness (depth or protrusion of the fastener in a countersunk hole)e = distance, parallel to force, from hole center to end of specimen; the edge distanceExbr = bearing chord stiffness in
36、the test direction specified by the subscript (for determination of offset bearing strength)f = distance, parallel to force, from hole edge to end of specimenFxbru = ultimate bearing strength in the test direction specified by the subscriptFxbro (e %) = offset bearing strength (at e % bearing strain
37、 offset) in the test direction specified by the subscriptg = distance, perpendicular to force, from hole edge to shortest edge of specimenh = specimen thicknessk = calculation factor used in bearing equations to distinguish single-fastener tests from double-fastener testsK = calculation factor used
38、in bearing equations to distinguish single-shear tests from double-shear tests in a single bearing holedeformation in one member of the assembly from hole deformation shared between two members of the assembly in a strainequationLg = extensometer gage lengthn = number of specimens per sample populat
39、ionP = force carried by test specimenPf = force carried by test specimen at failurePmax = maximum force carried by test specimen prior to failuresn-1 = standard deviation statistic of a sample population for a given propertyw = specimen widthxi = test result for an individual specimen from the sampl
40、e population for a given propertyx = mean or average (estimate of mean) of a sample population for a given property = extensional displacement = general symbol for strain, whether normal strain or shear strainbr = bearing strainD5961/D5961M 133br = bearing stress4. Summary of Test Method4.1 Procedur
41、e A, Double Shear, Tension:4.1.1 A flat, constant rectangular cross-section test specimen with a centerline hole located near the end of the specimen, asshown in the test specimen drawings of Figs. 1 and 2, is loaded at the hole in bearing.The bearing force is normally applied througha close-toleran
42、ce, lightly torqued fastener (or pin) that is reacted in double shear by a fixture similar to that shown in Figs. 3 and4. The bearing force is created by loading the assembly in tension in a testing machine.4.1.2 Both the applied force and the associated deformation of the hole are monitored. The ho
43、le deformation is normalized bythe hole diameter to create an effective bearing strain. Likewise, the applied force is normalized by the projected hole area to createan effective bearing stress. The specimen is loaded until a maximum force has clearly been reached, whereupon the test isterminated so
44、 as to prevent masking of the true failure mode by large-scale hole distortion, in order to provide a more representativefailure mode assessment. Bearing stress versus bearing strain for the entire loading regime is plotted, and failure mode noted. Theultimate bearing strength of the material is det
45、ermined from the maximum force carried prior to test termination.4.1.3 The standard test configuration for this procedure does not allow any variation of the major test parameters. However, thefollowing variations in specimen and test fixture configuration are allowed, but can be considered as being
46、 in accordance with thistest method only as long as the values of all variant test parameters are prominently documented with the results:Parameter Standard VariationLoading condition: double-shear noneMating material: steel fixture noneFIG. 1 Double-Shear and Single-Shear One-Piece Test Specimen Dr
47、awing (SI)D5961/D5961M 134Parameter Standard VariationNumber 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 ra
48、tio: 3 any, if documentedw/D ratio: 6 any, if documentedD/h ratio: 1.2-2 any, if documented4.2 Procedure B, Single Shear, Two-Piece Specimen:4.2.1 The flat, constant rectangular cross-section test specimen is composed of two like halves fastened together through oneor two centerline holes located ne
49、ar one end of each half, as shown in the test specimen drawings of Figs. 5-8. The eccentricityin applied force that would otherwise result is minimized by a doubler bonded to, or frictionally retained against each grip end ofthe specimen, resulting in a force line-of-action along the interface between the specimen halves, through the centerline of thehole(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.
