1、Designation: D7332/D7332M 15AStandard 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
2、or, 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 multidirec
3、tional 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. T
4、he 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 pr
5、ocedures 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 fa
6、steners/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. The values stated ineach system are not exact equivalents; therefore, each systemmust be us
8、ed independently of the other. Combining valuesfrom the two systems may result in nonconformance with thestandard.1.5.1 Within the text the inch-pound units are shown inbrackets.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespons
9、ibility 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 Displace
10、mentD883 Terminology Relating to PlasticsD3171 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 Me
11、thod for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite 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 Me
12、thods of Mechanical TestingE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE122 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 MethodsE456 Ter
13、minology 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
14、 D30 onComposite Materials and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition approved May 15, 2015. Published May 2015. Originallyapproved in 2007. Last previous edition approved in 2015 as D7332/D7332M15.DOI: 10.1520/D7332_D7332M-15A.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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959. United States12.2 Industry Documents:CMH-17-1G Composite Materials Handbook, Volume1Polymer Matrix Composites Guidelines for Character-ization of Structural Materials33. Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto composite materials. Terminology D883 d
17、efines termsrelating to plastics. Terminology E6 defines terms relating tomechanical testing. Terminology E456 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 represents a
18、 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, for thermodynamic temper
19、ature,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, D/h nd
20、, 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 the fi
21、rst 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 10 %) d
22、rops 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 nominalvalue to de
23、fine 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 coordinatesys
24、tem 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 coordina
25、te 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 laminat
26、ed 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 the ply
27、 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 testlaminate, caused by failure of the fastener, the composite plate,or both. Rupture is characterized by an extreme force
28、drop,such that the specimen is incapable of carrying significantapplied force.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 symmetric laminat
29、e 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 property (in
30、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= maximum
31、 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 propertyx5 mean or average (estimate of mean) of a samplepopulation for a given p
32、ropertyi= displacement at initial failurer= 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-piece fixture tha
33、t has been aligned tominimize 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 are pried apa
34、rt by the application ofcompressive force transmitted through the fixture, producing a3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096, http:/www.sae.orgD7332/D7332M 15A2tensile loading through the fastener and a compressive loadingthrough the composite plates. Forc
35、e is applied until failure ofthe composite specimen, the fastener, or both occurs. Appliedforce and crosshead displacement are recorded while loading.4.2 Procedure B, Tensile-Loaded Fixture:4.2.1 A flat square, constant rectangular cross-section com-posite plate containing a centrally located fasten
36、er 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 a tensile loadi
37、ng 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 are thoseassocia
38、ted 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 produce fastener pull
39、-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.However, the flexibility of test parameters allowed by thevar
40、iants makes meaningful comparison between datasets diffi-cult if the datasets were not generated using identical testparameters.5.2 Early composite pull-through tests using fasteners com-mon to metal structures led to premature joint failures, andresulted in the development of fasteners specific for
41、 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: material, methods of
42、material prepara-tion and lay-up, specimen stacking sequence, specimenpreparation, specimen conditioning, environment of testing,specimen alignment, speed of testing, time at temperature, voidcontent, and volume percent reinforcement.5.4 Specific factors that influence the pull-through resis-tance o
43、f 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 to thick-ness ratio
44、, 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-critical failure force
45、/displacement, failure force, maximum force, and rupture dis-placement.6. Interferences6.1 Material and Specimen PreparationPoor material fab-rication practices, lack of control of fiber alignment, anddamage induced by improper specimen machining are knowncauses of high material data scatter in comp
46、osites 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 presenceof the filled hol
47、e, results from this test method are relativelyinsensitive to parameters that would be of concern in anunnotched tensile, compressive or flexural property test.However, since the filled hole dominates the strength, consis-tent preparation of the hole, without damage to the laminate, isimportant to m
48、eaningful results. Damage caused by holepreparation will affect strength results and can reduce thecalculated strength.6.3 Fastener Head Style and CountersinkResults are af-fected by the head style of the fastener utilized. In general,specimens containing protruding head fasteners exhibit thehighest
49、 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 change the ob
