1、Designation: D 5448/D 5448M 93 (Reapproved 2006)Standard Test Method forInplane Shear Properties of Hoop Wound Polymer MatrixComposite Cylinders1This standard is issued under the fixed designation D 5448/D 5448M; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method determines the inplane shear propertiesof wound polymer ma
3、trix composites reinforced by high-modulus continuous fibers. It describes testing of hoop wound(90) cylinders in torsion for determination of inplane shearproperties.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text theinch-pound
4、units are shown in brackets. 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 thetest method.1.3 This standard does not purport to address all of thesafety
5、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.2. Referenced Documents2.1 ASTM Standards:2D 792 Test Methods for Density and
6、Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 2584 Test Method for Ignition Loss of Cured ReinforcedResinsD 2734 Test Methods for Void Content of Reinforced Plas-ticsD 3171 Test Methods for Constituent Content of CompositeMaterialsD 3878 Term
7、inology for Composite MaterialsD 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsD 5449/D 5449M Test Method for Transverse CompressiveProperties of Hoop Wound Polymer Matrix CompositeCylindersD 5450/D 5450M Test Method for
8、 Transverse Tensile Prop-erties of Hoop Wound Polymer Matrix Composite Cylin-dersE6 Terminology Relating to Methods of Mechanical Test-ingE 111 Test Method forYoungs Modulus, Tangent Modulus,and Chord ModulusE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the
9、 Average for aCharacteristic of a Lot or ProcessE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 251 Test Methods for Performance Characteristics ofMetallic Bonded Resistance Strain GagesE 456 Terminology Relating to Quality and StatisticsE 691 Practice for Conducting an I
10、nterlaboratory Study toDetermine the Precision of a Test MethodE 1237 Guide for Installing Bonded Resistance StrainGages3. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto high-modulus fibers and their composites. TerminologyD 883 defines terms relating to plastics. Terminology
11、E6defines terms relating to mechanical testing. TerminologyE 456 and Practice E 177 define terms relating to statistics. Inthe event of a conflict between terms, Terminology D 3878shall have precedence over other standards.1This test method is under the jurisdiction of ASTM Committee D30 onComposite
12、 Materials and is the direct responsibility of Subcommittee D30.04 onLamina and Laminate Test Methods.Current edition approved Jan. 15, 2006. Published January 2006. Originallyapproved in 1993. Last previous edition approved in 2000 as D 5448/D 5448M 93(2000).2For referenced ASTM standards, visit th
13、e 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 Conshohocken, PA 19428-2959,
14、United States.3.2 Description of Terms Specific to This Standard:33.2.1 hoop wound, na winding of a cylindrical componentwhere the filaments are circumferentially oriented.3.2.2 inplane shear modulus, G12 MT1T2, nthe elasticshear modulus of a unidirectional material in the plane definedby axes paral
15、lel and perpendicular to the reinforcing fibers.3.2.3 inplane shear strain at failure, g12und, nthe valueof inplane shear strain at failure when an inplane shear load isapplied to the material.3.2.4 inplane shear strength, t12,MT2L1, nthestrength of a unidirectional material when an inplane shear lo
16、adis applied to the material.3.2.5 specimena single part cut from a winding that meetsthe specifications of Fig. 1. Each winding may yield severalspecimens.3.2.6 windingan entire part completed by one windingoperation and then cured.4. Summary of Test Method4.1 A thin walled hoop wound cylinder nomi
17、nally 100 mm4 in. in diameter and 140 mm 512 in. in length is bondedinto two end fixtures. The specimen/fixture assembly ismounted in the testing machine and monotonically loaded ininplane shear while recording load. The inplane shear strengthcan be determined from the maximum load carried prior tof
18、ailure. If the cylinder strain is monitored with strain gagesthen the stress-strain response, the inplane shear strain atfailure, and the inplane shear modulus can be derived.5. Significance and Use5.1 This test method is designed to produce inplane shearproperty data for material specifications, re
19、search and devel-opment, quality assurance, and structural design and analysis.Factors that influence the inplane shear response and shouldtherefore be reported are material, method of material prepa-ration, specimen preparation, specimen conditioning, environ-ment of testing, specimen alignment and
20、 gripping, speed oftesting, void content, and fiber volume fraction. Properties, inthe test direction, that may be obtained from this test methodare as follows:5.1.1 Inplane Shear Strength, t12u,5.1.2 Inplane Shear Strain at Failure, g12u, and5.1.3 Inplane Shear Modulus, G12.6. Interferences6.1 Mate
21、rial and Specimen PreparationPoor materialfabrication practices, lack of control of fiber alignment, anddamage induced by improper coupon machining are knowncauses of high material data scatter in composites.6.2 Bonding Specimens to Test FixturesAhigh percentageof failures in or near the bond betwee
22、n the test specimen andthe test fixture, especially when combined with high materialdata scatter, is an indicator of specimen bonding problems.Specimen-to-fixture bonding is discussed in 11.5.6.3 System AlignmentExcessive bending or axial loadingwill cause premature failure, as well as highly inaccu
23、rate shearmodulus determination. Every effort should be made to elimi-nate excess bending and axial loading from the test system.Bending and axial loading may occur due to misaligned grips,misaligned specimens in the test fixtures, or from departures ofthe specimens from tolerance requirements. The
24、alignmentshould always be checked as discussed in 12.2.7. Apparatus7.1 Micrometers, suitable ball type for reading to within0.025 6 0.010 mm 0.001 6 0.0004 in. of the specimen innerand outer diameters. Flat anvil type or micrometer calipers ofsimilar resolution may be used for the overall specimen l
25、engthand the gage length (the free length between the fixtures).7.2 Inplane Shear FixtureThe inplane shear fixture con-sists of a steel outer shell, insert, and adaptor. An assemblydrawing for these components and the test fixture is shown inFig. 1.7.2.1 Outer ShellThe outer shell (SI units, see Fig
26、. 2;inch-pound units, see Fig. 3) is circular with a concentriccircular hollow in one face, a groove along the diameter of theother face, and a center hole through the thickness. Along thediameter perpendicular to the groove, three pairs of smalleccentric holes are placed at three radial distances.
27、The twoouter pairs of holes are threaded. Four additional threadedholes are placed at the same radial distance as the innermostpair of holes at 90 intervals starting 45 from the diameter thatpasses through the center groove.7.2.2 InsertThe fixture insert is circular with a center holethrough the thi
28、ckness (SI units, see Fig. 4; inch-pound units,see Fig. 5). Two sets of holes are placed along a concentriccenterline. These holes align with the innermost set of holes inthe outer shell. The set of 4 holes at 90 intervals arecounterbored. The insert is fastened inside the hollow of theouter shell t
29、o form the concentric groove used to put thespecimen in the fixture.3If the term represents a physical quantity, its analytical dimensions are statedimmediately following the term (or letter symbol) in fundamental dimension form,using the followingASTM standard symbology for fundamental dimensions,
30、shownwithin square brackets: M for mass, L for length, T for time, u forthermodynamic temperature, and nd for nondimensional quantities. Use of thesesymbols is restricted to analytical dimensions when used with square brackets, as thesymbols may have other definitions when used without the brackets.
31、FIG. 1 Assembly Drawing for the Shear Fixture and SpecimenD 5448/D 5448M 93 (2006)27.2.3 AdaptorThe adaptor is circular with a square centraltorque nut raising out of one face, a flange along a diameter onthe other face, and a central hole (SI units, see Fig. 6;inch-pound units, see Fig. 7). Two bol
32、t holes are placedequidistant from the adaptor center on a diameter perpendicularto the centerline of the flange. The adaptor is fastened to theouter shell. The flange of the adaptor fits into the groove of theouter shell. The complete inplane shear specimen/fixture as-sembly is seen in Fig. 1.NOTE
33、1The outer shell and insert for the compression fixture are thesame outer shell and insert used for the fixtures in Test MethodsD 5449/D 5449M and D 5450/D 5450M.7.3 Testing Machine, comprised of the following:7.3.1 Fixed MemberA fixed or essentially stationarymember, with respect to rotation, to wh
34、ich one end of thetorsion specimen/fixture/adaptor assembly, shown in Fig. 3,can be attached.7.3.2 Rotational MemberA rotational member to whichthe opposite end of the torsion specimen/fixture/adaptor assem-bly, shown in Fig. 1, can be attached. Either the rotationalmember or the fixed member shall
35、be free to move axially toprevent the application of axial forces or the axial load shall belimited to 5 % of the axial strength of the material.7.3.3 Drive Mechanism, for imparting to the movable mem-ber a uniform controlled angular velocity with respect to thefixed member. This angular velocity is
36、 to be regulated asspecified in Section 9.FIG. 2 Outer Shell of the Shear Fixture in SI UnitsD 5448/D 5448M 93 (2006)37.3.4 Load IndicatorA suitable load-indicating mecha-nism capable of showing the total torsional load carried by thetest specimen. This mechanism shall be essentially free ofinertia-
37、lag at the specified rate of testing and shall indicate theload within an accuracy of 61 % of the actual value, or better.7.3.5 Construction MaterialsThe fixed member, movablemember, drive mechanism, fixtures, and adaptors shall beconstructed of such materials and in such proportions that thetotal r
38、otational deformation of the system contributed by theseparts is minimized.7.4 Strain-Indicating DeviceLoad versus strain data shallbe determined by means of bonded resistance strain gages.Each strain gage shall be 6.3 mm 0.25 in. in length. Straingage rosettes (0/45/90) shall be used to correct for
39、 gagemisalignment. Gage calibration certification shall comply withTest Method E 251. Some guidelines on the use of strain gageson composites are presented in 7.4.1-7.4.4.Ageneral referenceon the subject is Tuttle and Brinson.47.4.1 Surface PreparationThe surface preparation offiber-reinforced compo
40、sites discussed in Guide E 1237 canpenetrate the matrix material and cause damage to the rein-forcing fibers, resulting in improper coupon failures. Reinforc-ing fibers should not be exposed or damaged during the surfacepreparation process. The strain gage manufacturer should beconsulted regarding s
41、urface preparation guidelines and recom-mended bonding agents for composites, pending the develop-ment of a set of standard practices for strain gage installationsurface preparation of fiber-reinforced composite materials.4Tuttle, M. E. and Brinson, H. F., “Resistance-Foil Strain-Gage Technology asA
42、pplied to Composite Materials,” Experimental Mechanics, Vol 24, No. 1, March1984, pp. 5464; errata noted in Vol 26, No. 2, January 1986, pp. 153154.FIG. 3 Outer Shell for the Shear Fixture in Inch-Pound UnitsD 5448/D 5448M 93 (2006)47.4.2 Gage ResistanceConsideration should be given tothe selection
43、of gages having larger resistance to reduceheating effects on low-conductivity materials. Resistances of350V or higher are preferred.Additional considerations shouldbe given to the use of the minimum possible gage excitationvoltage consistent with the desired accuracy (1 to 2 V isrecommended) to fur
44、ther reduce the power consumed by thegage. Heating of the coupon by the gage may affect theperformance of the material directly, or it may affect theindicated strain due to a difference between the gage tempera-ture compensation factor and the coefficient of thermal expan-sion of the coupon material
45、.7.4.3 Temperature ConsiderationsConsideration of someform of temperature compensation is recommended, evenwhen testing at standard laboratory atmosphere. Temperaturecompensation is required when testing in nonambient tempera-ture environments.7.4.4 Transverse SensitivityConsideration should begiven
46、 to the transverse sensitivity of the selected strain gage.The strain gage manufacturer should be consulted for recom-mendations on transverse sensitivity corrections and effects oncomposites.7.5 Conditioning ChamberWhen conditioning materialsat nonlaboratory environments, a temperature/vapor-level
47、con-trolled environment conditioning chamber is required whichshall be capable of maintaining the required temperature towithin 63C 65F and the required relative vapor level towithin 63 %. Chamber conditions shall be monitored either onan automated continuous basis or on a manual basis at regularint
48、ervals.FIG. 4 Insert of the Shear Fixture in SI UnitsD 5448/D 5448M 93 (2006)57.6 Environmental Test ChamberAn environmental testchamber is required for testing environments other than ambi-ent testing laboratory conditions. This chamber shall be ca-pable of maintaining the gage section of the test
49、specimen atthe required test environment during the mechanical test.8. Sampling and Test Specimens8.1 SamplingAt least five specimens per test conditionshould be tested unless valid results can be gained through theuse of fewer specimens, such as in the case of a designedexperiment. For statistically significant data, the proceduresoutlined in Practice E 122 should be consulted. The method ofsampling shall be reported.8.2 GeometryThe test specimen shall be as shown in Fig.8. The length of all specimens shal
