ASTM D5467 D5467M-1997(2017) Standard Test Method for Compressive Properties of Unidirectional Polymer Matrix Composite Materials Using a Sandwich Beam《使用多层组合梁的单向聚合母体复合材料压缩特性的标准试验方.pdf

1、Designation: D5467/D5467M 97 (Reapproved 2017)Standard Test Method forCompressive Properties of Unidirectional Polymer MatrixComposite Materials Using a Sandwich Beam1This standard is issued under the fixed designation D5467/D5467M; the number immediately following the designation indicates theyear

2、of original adoption 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 covers the in-plane compressive prop-er

3、ties of polymer matrix composite materials reinforced byhigh-modulus fibers in a sandwich beam configuration. Thecomposite material forms are limited to continuous-fiber com-posites of unidirectional orientation. This test procedure intro-duces compressive load into a thin skin bonded to a thickhone

4、ycomb core with the compressive load transmitted into thesample by subjecting the beam to four-point bending.1.2 This procedure is applicable primarily to laminatesmade from prepreg or similar product forms. Other productforms may require deviations from the test method.1.3 The values stated in eith

5、er SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3.1 Within the

6、 text the inch-pound units are shown inbrackets.NOTE 1Additional procedures for determining compressive propertiesof polymer matrix composites may be found in Test Methods D3410/D3410M and D695.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use.

7、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:2D695 Test Method for Compressive Properties of RigidPlasticsD792 Test Methods

8、for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD2734 Test Methods for Void Content of Reinforced PlasticsD3171 Test Methods for Constituent Content of CompositeMaterials

9、D3410/D3410M Test Method for Compressive Properties ofPolymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite Materials

10、E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE111 Test Method for Youngs Modulus, Tangent Modulus,and Chord ModulusE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic of aLo

11、t or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE251 Test Methods for Performance Characteristics of Me-tallic Bonded Resistance Strain GagesE456 Terminology Relating to Quality and StatisticsE1237 Guide for Installing Bonded Resistance Strain GagesE1309 Guide fo

12、r Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in Databases (With-drawn 2015)3E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases (Withdrawn2015)3E1471 Guide for Identification of Fibers, Fillers, and CoreMaterials in Computeriz

13、ed Material Property Databases(Withdrawn 2015)31This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.04 onLamina and Laminate Test Methods.Current edition approved Jan. 1, 2017. Published January 2017. Originallya

14、pproved in 1993. Last previous edition approved in 2010 as D5467/D5467M 97(2010). DOI: 10.1520/D5467_D5467M-97R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to th

15、e standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accor

16、dance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13. Terminology3.1 DefinitionsTer

17、minology D3878 defines terms relatingto high-modulus fibers and their composites. TerminologyD883 defines terms relating to plastics.Terminology E6 definesterms relating to mechanical testing. Terminology E456 andPractice E177 define terms relating to statistics. In the event ofa conflict between te

18、rms, Terminology D3878 shall haveprecedence over the other terminology standards.3.2 Definitions of Terms Specific to This Standard:3.2.1 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 nomina

19、lvalue to define an acceptable range for the property.3.2.2 orthotropic material, na material with a property ofinterest that, at a given point, possesses three mutually perpen-dicular planes of symmetry defining the principal materialcoordinate system for that property.3.2.3 principal material coor

20、dinate system, na coordinatesystem with axes that are normal to the planes of symmetry thatexist within the material.3.2.4 reference coordinate system, na coordinate systemfor laminated composites used to define ply orientations. Oneof the reference coordinate system axes (normally the Carte-sian x-

21、axis) is designated the reference axis, assigned aposition, and the ply principal axis of each ply in the laminateis referenced relative to the reference axis to define the plyorientation for that ply.3.2.5 specially orthotropic, adja description of an ortho-tropic material as viewed in its principa

22、l material coordinatesystem. In laminated composites, a specially orthotropic lami-nate is a balanced and symmetric laminate of the (0i/90j)nsfamily as viewed from the reference coordinate system, suchthat the membrane-bending coupling terms of the stress-strainrelation are zero.3.2.6 transition str

23、ain, transition,nthe strain value at themid-range of the transition region between the two essentiallylinear portions of a bilinear stress-strain or strain-strain curve(a transverse strain-longitudinal strain curve as used for deter-mining Poissons ratio).3.3 Symbols:3.3.1 adistance between neutral

24、axes of test and oppositefacesheets.3.3.2 Across-sectional area of test facesheet.3.3.3 CVsample coefficient of variation, in percent.3.3.4 Eomodulus of elasticity of the opposite facesheet inthe test direction.3.3.5 Efmodulus of elasticity of the test facesheet in thetest direction.3.3.6 Fcuultimat

25、e compressive strength.3.3.7 Gxzthrough-thickness shear modulus of elasticity.3.3.8 hcthickness of core.3.3.9 ccompressive normal stress.4. Summary of Test Method4.1 Asandwich beam composed of two facesheets separatedby a relatively deep honeycomb core, as shown in Fig. 1,isloaded in four-point bend

26、ing. The main component of thecompression test specimen is the face sheet that is loaded inFIG. 1 Longitudinal Compression Sandwich Beam Test SpecimenD5467/D5467M 97 (2017)2compression during flexure, with the material direction ofinterest oriented along the length of the beam. The otherfacesheet is

27、 of a material and size carefully selected to precludeits influence on the test results. The ultimate compressivestrength of the material is determined from the load at whichthe test facesheet of the sandwich beam fails in an acceptablecompression failure mode. If the specimen strain is monitoredwit

28、h strain or deflection transducers then the stress-strainresponse of the material can be determined, from which can bederived the compressive modulus of elasticity for this configu-ration.5. Significance and Use5.1 This test method is designed to produce membranecompressive property data for materia

29、l specifications, researchand development, quality assurance, and structural design andanalysis. Factors that influence the compressive response andshould therefore be reported include the following: material,methods of material and specimen preparation, specimenconditioning, environment of testing,

30、 specimen alignment,speed of testing, time at reinforcement. Properties, in the testdirection, that may be obtained from this test method include:5.1.1 Ultimate compressive strength,5.1.2 Ultimate compressive strain,5.1.3 Compressive (linear or chord) modulus of elasticity,and5.1.4 Transition strain

31、.6. Interferences6.1 Test Method SensitivitiesCompressive strength for asingle material system has been shown to differ when deter-mined by different test methods. Such differences can beattributed to specimen alignment effects, specimen geometryeffects, and fixture effects even though efforts have

32、been madeto minimize these effects.6.2 Material and Specimen PreparationCompressivemodulus, and especially compressive strength, are sensitive topoor material fabrication practices, damage induced by im-proper coupon machining, and lack of control of fiber align-ment. Fiber alignment relative to the

33、 specimen coordinate axisshould be maintained as carefully as possible, although nostandard procedure to insure this alignment exists. Proceduresfound satisfactory include the following: fracturing a curedunidirectional laminate near one edge parallel to the fiberdirection to establish the 0 directi

34、on or laying in smallfilament count tows of contrasting color fiber (aramid in carbonlaminates and carbon in aramid or glass laminates) parallel tothe 0 direction either as part of the prepreg production or aspart of panel fabrication.6.3 CalculationStress equations are based on beamtheory.7. Appara

35、tus7.1 MicrometersThe micrometer(s) shall use a suitablesize diameter ball-interface on irregular surfaces such as thebag-side of a laminate, and a flat anvil interface on machinededges or very smooth tooled surfaces. The accuracy of theinstruments shall be suitable for reading to within 1 % of thes

36、ample width and thickness. For typical specimen geometries,an instrument with an accuracy of 62.5 m 60.0001 in. isdesirable for thickness measurement, while an instrument withan accuracy of 625 m 60.001 in. is desirable for widthmeasurement.7.2 Compressive FixtureA fixture of four loading cylin-ders

37、 or cylindrical supports capable of loading the sandwichbeam as shown in Fig. 1. The fixture shall be installed betweenthe steel platens of the testing machine. To avoid local crushingor failure as a result of stress concentrations under the loadingcylinders, the diameter of loading cylinders may be

38、 up to 1.5times the sandwich thickness, and loading pads may be neededunder the loading cylinders (see 11.6).7.3 Testing MachineThe testing machine shall be in con-formance with Practices E4 and shall satisfy the followingrequirements:7.3.1 Testing Machine HeadsThe testing machine shallhave two load

39、ing heads, with at least one movable along thetesting axis.7.3.2 Drive MechanismThe testing machine drive mecha-nism shall be capable of imparting to the movable head acontrolled displacement rate with respect to the stationaryhead. The displacement rate of the movable head shall becapable of being

40、regulated as specified in 11.3.7.3.3 Load IndicatorThe testing machine load-sensingdevice shall be capable of indicating the total load beingcarried by the test specimen. This device shall be essentiallyfree from inertia lag at the specified rate of testing and shallindicate the load with an accurac

41、y over the load range(s) ofinterest of within 61 % of the indicated value, as specified byPractices E4.The load range(s) of interest may be fairly low formodulus evaluation, much higher for strength evaluation, orboth, as required.NOTE 2Obtaining precision load data over a large range of interest in

42、the same test, such as when both elastic modulus and ultimate load arebeing determined, place extreme requirements on the load cell and itscalibration. For some equipment, a special calibration may be required.For some combinations of material and load cell, simultaneous precisionmeasurement of both

43、 elastic modulus and ultimate strength may not bepossible, and measurement of modulus and strength may have to beperformed in separate tests using a different load cell range for each test.7.4 Strain-Indicating DeviceStrain data, if required, shallbe determined by means of strain gages.7.4.1 Bonded

44、Resistance Strain GagesStrain gage selec-tion is a compromise based on the procedure and the type ofmaterial to be tested. Strain gages should have an active gridlength of 3 mm 0.125 in. or less; (1.5 mm 0.06 in. ispreferable). Gage calibration certification shall comply withTest Methods E251. Some

45、guidelines on the use of strain gageson composites are presented below, with a general discussionon the subject in Footnote 8.47.4.1.1 Surface preparation of fiber-reinforced compositesin accordance with Practice E1237 can penetrate the matrixmaterial and cause damage to the reinforcing fibers, resu

46、lting4Pendleton, R. P. and Tuttle, M. E., Manual on Experimental Methods forMechanical Testing of Composites, Society for Experimental Mechanics, Bethel,CT, 1989.D5467/D5467M 97 (2017)3in improper coupon failures. Reinforcing fibers shall not beexposed or damaged during the surface preparation proce

47、ss.Consult the strain gage manufacturer regarding surface prepa-ration guidelines and recommended bonding agents for com-posites.7.4.1.2 Select gages having larger resistances to reduceheating effects on low-conductivity materials. Resistances of350 or higher are preferred. Use the minimum possible

48、gageexcitation voltage consistent with the desired accuracy (1 to 2V is recommended) to reduce further the power consumed bythe gage. Heating of the coupon by the gage may affect theperformance of the material directly, or it may affect theindicated strain as a result of a difference between the gag

49、etemperature compensation factor and the coefficient of thermalexpansion of the coupon material.7.4.1.3 Temperature compensation is recommended whentesting at Standard Laboratory Atmosphere. Temperature com-pensation is required when testing in nonambient temperatureenvironments. When appropriate, use a traveler coupon(dummy calibration coupon) with identical lay-up and straingage orientations for thermal strain compensation.7.4.1.4 Consider the transverse sensitivity of the selectedstrain gage. Consult the strain gage manufacturer