1、Designation: D7332/D7332M 09Standard Test Method forMeasuring the Fastener Pull-Through Resistance of aFiber-Reinforced Polymer Matrix Composite1This standard is issued under the fixed designation D7332/D7332M; the number immediately following the designation indicates theyear of original adoption o
2、r, 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 fastener pull-throughresistance of multidirect
3、ional polymer matrix composites rein-forced by high-modulus fibers. Fastener pull-through resis-tance is characterized by the force-versus-displacement re-sponse exhibited when a mechanical fastener is pulled througha composite plate, with the force applied perpendicular to theplane of the plate. Th
4、e composite material forms are limited tocontinuous-fiber or discontinuous-fiber (tape or fabric, or both)reinforced composites for which the laminate is symmetric andbalanced with respect to the test direction. The range ofacceptable test laminates and thicknesses is defined in 8.2.1.2 Two test pro
5、cedures and configurations are provided.The first, Procedure A, is suitable for screening and fastenerdevelopment purposes. The second, Procedure B, isconfiguration-dependent and is suitable for establishing designvalues. Both procedures can be used to perform comparativeevaluations of candidate fas
6、teners/fastener system designs.1.3 The specimens described herein may not be representa-tive of actual joints which may contain one or more free edgesadjacent to the fastener, or may contain multiple fasteners thatcan change the actual boundary conditions.1.4 This test method is consistent with the
7、recommendationsof CMH-17, which describes the desirable attributes of afastener pull-through test method.1.5 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 brackets. The values stated ineach system a
8、re not exact equivalents; therefore, each systemmust be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with thestandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
9、y 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 DisplacementD8
10、83 Terminology Relating to PlasticsD3171 Test Methods for Constituent Content of CompositeMaterialsD3410/D3410M Test Method for Compressive Propertiesof Polymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3878 Terminology for Composite MaterialsD5229/D5229M Test Method f
11、or Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods
12、 of Mechanical TestingE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminol
13、ogy Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases1This test method is under the jurisdiction of ASTM Committee D30
14、onComposite Materials and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved Sept. 1, 2009. Published October 2009. Originallyapproved in 2007. Last previous edition approved in 2007 as D7332/D7332M071.DOI: 10.1520/D7332_D7332M-09.2For referenced A
15、STM 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 Consho
16、hocken, PA 19428-2959, United States.2.2 Industry Documents:CMH-17-1F Composite Materials Handbook, Volume1Polymer Matrix Composites Guidelines for Character-ization of Structural Materials33. Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto composite materials. Terminology D883
17、defines termsrelating to plastics. Terminology E6 defines terms relating tomechanical testing. Terminology E456E456 and Practice E177define terms relating to statistics. In the event of a conflictbetween terms, Terminology D3878 shall have precedenceover the other standards.NOTE 1If the term represe
18、nts 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, shown within square brackets: Mfor mass, L for length, T for time, u for thermodynamic
19、 temperature,and nd for non-dimensional 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.3.2 Definitions of Terms Specific to This Standard:3.2.1 diameter-to-thickness ratio,
20、 D/h nd, nthe ratio ofthe hole diameter to the specimen thickness.3.2.1.1 DiscussionThe diameter-to-thickness ratio may beeither a nominal value determined from nominal dimensions oran actual value determined from measured dimensions.3.2.2 failure force, nthe maximum force magnitudeachieved prior to
21、 the first significant (greater than 10 %) dropin applied force, as observed in force versus displacement data.3.2.3 initial sub-critical failure, ndiscontinuity observedin force versus displacement data prior to attaining the failureforce. Sub-critical failures are characterized by minor (lessthan
22、10 %) drops in applied force, or by compliance changes(greater than 10 % change in slope), prior to attaining thefailure force.3.2.4 nominal value, na value, existing in name only,assigned to a measurable property for the purpose of conve-nient designation. Tolerances may be applied to a nominalvalu
23、e to define an acceptable range for the property.3.2.5 principal material coordinate system, na coordinatesystem with axes that are normal to the planes of symmetryinherent to a material.3.2.5.1 DiscussionCommon usage, at least for Cartesianaxes (123, xyz, and so forth), generally assigns the coordi
24、natesystem axes to the normal directions of planes of symmetry inorder that the highest property value in a normal direction (forelastic properties, the axis of greatest stiffness) would be 1 orx, and the lowest (if applicable) would be 3 or z. Anisotropicmaterials do not have a principal material c
25、oordinate systemdue to the total lack of symmetry, while, for isotropic materials,any coordinate system is a principal material coordinatesystem. In laminated composites, the principal material coor-dinate system has meaning only with respect to an individualorthotropic lamina. The related term for
26、laminated compositesis “reference coordinate system.”3.2.6 reference coordinate system, na coordinate systemfor laminated composites used to define ply orientations. Oneof the reference coordinate system axes (normally the Carte-sian x-axis) is designated the reference axis, assigned aposition, and
27、the ply principal axis of each ply in the laminateis referenced relative to the reference axis to define the plyorientation for that ply.3.2.7 rupture, nseparation of the fastener and test lami-nate, caused by failure of the fastener, the composite plate, orboth. Rupture is characterized by an extre
28、me force drop, suchthat the specimen is incapable of carrying significant appliedforce.3.2.8 specially orthotropic, adja description of an ortho-tropic material as viewed in its principal material coordinatesystem. In laminated composites, a specially orthotropic lami-nate is a balanced and symmetri
29、c laminate of the 0i/90jnsfamily as viewed from the reference coordinate system, suchthat the membrane-bending coupling terms of the laminateconstitutive relation are zero.3.3 Symbols:A = cross-sectional area of a specimenCV = coefficient of variation statistic of a sample populationfor a given prop
30、erty (in percent)d = fastener or pin shank diameterdcsk= countersink depthD = specimen hole diameterh = specimen thicknessl = specimen lengthn = number of specimens per sample populationN = number of plies in laminate under testPf= failure forcePi= force carried by test specimen at initial failurePm
31、= maximum force carried by test specimen during testsn-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 samplepopulation for
32、 a given propertydi= displacement at initial failuredr= displacement at rupture4. Summary of Test Method4.1 Procedure A, Compressive-Loaded Fixture:4.1.1 Two flat square, constant rectangular cross-sectioncomposite plates, each containing a centrally located fastenerhole, are placed in a multi- piec
33、e fixture that has been alignedto minimize loading eccentricities. Each plate contains fouradditional holes on the periphery to accommodate the testfixture components. The two plates are joined together by thefastener, with one plate being rotated 45 with respect to thesecond plate.4.1.2 The plates
34、are pried apart by the application ofcompressive force transmitted through the fixture, producing atensile loading through the fastener and a compressive loadingthrough the composite plates. Force is applied until failure ofthe composite specimen, the fastener, or both occurs. Appliedforce and cross
35、head displacement are recorded while loading.3Available from U.S. Army Research Laboratory, Materials Directorate, Aber-deen Proving Ground, MD 21001.D7332/D7332M 0924.2 Procedure B, Tensile-Loaded Fixture:4.2.1 A flat square, constant rectangular cross-section com-posite plate containing a centrall
36、y located fastener hole isplaced in a multi-piece fixture that has been aligned tominimize loading eccentricities. The plate is joined by thefastener to a yoke, which is designed to rotate as to avoidimparting a moment to the fastener.4.2.2 A uniaxial tensile force is applied to the yoke, impart-ing
37、 a tensile loading on the fastener and an out-of-planecompressive loading on the composite plate. Force is applieduntil failure of the composite specimen, the fastener, or bothoccurs. Applied force and crosshead displacement are recordedwhile loading.4.3 For both procedures, preferred failure modes
38、are thoseassociated with failure of the composite at the fastener hole.Unacceptable failure modes include those associated with thefastener (such as head, shank or thread failure) or failure of thecomposite away from the fastener hole.5. Significance and Use5.1 This test method is designed to produc
39、e fastener pull-through resistance data for structural design allowables, re-search and development. The procedures may be used to assesspull-through resistance for a variety of composite laminatethicknesses, fastener diameters, and fastener head styles. How-ever, the flexibility of test parameters
40、allowed by the variantsmakes meaningful comparison between datasets difficult if thedatasets were not generated using identical test parameters.5.2 Early composite pull-through tests using fasteners com-mon to metal structures led to premature joint failures, andresulted in the development of fasten
41、ers specific for compositeapplications. These fasteners have larger heads and tails toreduce through-thickness compression stresses on the compos-ite laminate.5.3 General factors that influence the mechanical responseof composite laminates and should therefore be reportedinclude the following: mater
42、ial, methods of material prepara-tion and lay-up, specimen stacking sequence, specimen prepa-ration, specimen conditioning, environment of testing, speci-men alignment, speed of testing, time at temperature, voidcontent, and volume percent reinforcement.5.4 Specific factors that influence the pull-t
43、hrough resis-tance of composite laminates and should therefore be reportedinclude the following: hole diameter, fastener diameter, fas-tener head diameter, loading bar spacing to fastener holediameter ratio (Procedure A), clearance hole diameter tofastener hole diameter ratio (Procedure B), diameter
44、 to thick-ness ratio, fastener torque, fastener or pin material, fastener orpin clearance, countersink angle and depth of countersink, typeof grommet (if used), and type of support fixture. Fastenerpull-through resistance properties which may be determinedfrom this test method include initial sub-cr
45、itical failure force/displacement, failure force, maximum force, and rupture dis-placement.6. Interferences6.1 Material and Specimen PreparationPoor materialfabrication practices, lack of control of fiber alignment, anddamage induced by improper specimen machining are knowncauses of high material da
46、ta scatter in composites in general.Important aspects of specimen preparation that contribute todata scatter include thickness variation, out-of-plane curvature,surface roughness, and failure to meet the dimensional toler-ances specified in 8.2.2.6.2 Hole PreparationBecause of the dominating presenc
47、eof the filled hole, results from this test method are relativelyinsensitive to parameters that would be of concern in anunnotched tensile, compressive or flexural property test. How-ever, since the filled hole dominates the strength, consistentpreparation of the hole, without damage to the laminate
48、, isimportant to meaningful results. Damage caused by holepreparation will affect strength results and can reduce thecalculated strength.6.3 Fastener Head Style and CountersinkResults areaffected by the head style of the fastener utilized. In general,specimens containing protruding head fasteners ex
49、hibit thehighest pull-through resistance forces, followed by (in order ofdecreasing pull-through resistance forces) 100 tension headfasteners, 100 shear head fasteners, and 130 shear headfasteners. Results may also be affected by the ratio of counter-sunk (flush) head depth to thickness; the preferred ratio is therange from 0.0 to 0.7 unless the experiment is investigating theinfluence of this ratio.6.4 Fastener-Hole ClearanceResults are affected by theclearance arising from the difference between hole and fastenerdiameters. Excess clearance can ch
