1、Designation: C1358 18Standard Test Method forMonotonic Compressive Strength Testing of ContinuousFiber-Reinforced Advanced Ceramics with Solid RectangularCross Section Test Specimens at Ambient Temperatures1This standard is issued under the fixed designation C1358; the number immediately following t
2、he designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers
3、 the determination of compres-sive strength, including stress-strain behavior, under mono-tonic uniaxial loading of continuous fiber-reinforced advancedceramics at ambient temperatures. This test method addresses,but is not restricted to, various suggested test specimengeometries as listed in the ap
4、pendixes. In addition, testspecimen fabrication methods, testing modes (force,displacement, or strain control), testing rates (force rate, stressrate, displacement rate, or strain rate), allowable bending, anddata collection and reporting procedures are addressed. Com-pressive strength, as used in t
5、his test method, refers to thecompressive strength obtained under monotonic uniaxialloading, where monotonic refers to a continuous nonstop testrate with no reversals from test initiation to final fracture.1.2 This test method applies primarily to advanced ceramicmatrix composites with continuous fi
6、ber reinforcement: unidi-rectional (1D), bidirectional (2D), and tridirectional (3D) orother multi-directional reinforcements. In addition, this testmethod may also be used with glass (amorphous) matrixcomposites with 1D, 2D, 3D, and other multi-directionalcontinuous fiber reinforcements. This test
7、method does notdirectly address discontinuous fiber-reinforced, whisker-reinforced, or particulate-reinforced ceramics, although the testmethods detailed here may be equally applicable to thesecomposites.1.3 The values stated in SI units are to be regarded as thestandard and are in accordance with I
8、EEE/ASTM SI 10.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitatio
9、ns prior to use.Refer to Section 7 for specific precautions.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations
10、 issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsD695 Test Method for Compressive Properties of RigidPlasticsD3379 Test Method for Tensile Strength andYoungs Modu-lus for High-Modulus S
11、ingle-Filament MaterialsD3410/D3410M Test Method for Compressive Properties ofPolymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3479/D3479M Test Method for Tension-Tension Fatigueof Polymer Matrix Composite MaterialsD3878 Terminology for Composite MaterialsD6856/D6856M
12、 Guide for Testing Fabric-Reinforced “Tex-tile” Composite MaterialsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE337 Test Method for Measuring Humidity with a Ps
13、y-chrometer (the Measurement of Wet- and Dry-Bulb Tem-peratures)E1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce ApplicationIEEE/ASTM SI 10 American National Standard for MetricPractice3. Terminology3.1 Definitions:1This test method is
14、 under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.07 onCeramic Matrix Composites.Current edition approved July 1, 2018. Published July 2018. Originally approvedin 1996. Last previous edition approved in 2013 as C1358 13. DOI: 10.15
15、20/C1358-18.2For 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 the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Dri
16、ve, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations is
17、sued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.1 The definitions of terms relating to compressivetesting, advanced ceramics, and fiber-reinforced compositesappearing in Terminology E6, Test Method D695, PracticeE1012, Terminology C1145, Test Method D3410/D3410M
18、,and Terminology D3878 apply to the terms used in this testmethod. Pertinent definitions are shown as follows, with theappropriate source given in parentheses.Additional terms usedin conjunction with this test method are defined in 3.2.3.2 Definitions of Terms Specific to This Standard:3.2.1 advance
19、d ceramic, nhighly engineered, high-performance, predominantly non-metallic, inorganic, ceramicmaterial having specific functional attributes. C11453.2.2 axial strain LL1, naverage longitudinal strainsmeasured at the surface on opposite sides of the longitudinalaxis of symmetry of the specimen by tw
20、o strain sensing deviceslocated at the mid length of the reduced section. E10123.2.3 bending strain LL1, ndifference between thestrain at the surface and the axial strain. In general, the bendingstrain varies from point to point around and along the reducedsection of the specimen. E10123.2.4 breakin
21、g force F, nforce at which fracture occurs.E63.2.5 ceramic matrix composite, nmaterial consisting oftwo or more materials (insoluble in one another), in which themajor, continuous component (matrix component) is a ceramic,while the secondary component(s) (reinforcing component)may be ceramic, glass-
22、ceramic, glass, metal, or organic innature. These components are combined on a macroscale toform a useful engineering material possessing certain proper-ties or behavior not possessed by the individual constituents.3.2.6 compressive strength FL2, nmaximum compres-sive stress which a material is capa
23、ble of sustaining. Compres-sive strength is calculated from the maximum force during acompression test carried to rupture and the original cross-sectional area of the specimen. E63.2.7 continuous fiber-reinforced ceramic matrix composite(CFCC), nceramic matrix composite in which the reinforc-ing pha
24、se consists of a continuous fiber, continuous yarn, or awoven fabric.3.2.8 gage length L, noriginal length of that portion ofthe specimen over which strain or change of length isdetermined. E63.2.9 modulus of elasticity FL2, nratio of stress tocorresponding strain below the proportional limit. E63.2
25、.10 percent bending, nbending strain times 100 dividedby the axial strain. E10123.2.11 proportional limit stress in compression FL2,ngreatest stress that a material is capable of sustainingwithout any deviation from proportionality of stress to strain(Hookes law).3.2.11.1 DiscussionMany experiments
26、have shown thatvalues observed for the proportional limit vary greatly with thesensitivity and accuracy of the testing equipment, eccentricityof loading, the scale to which the stress-strain diagram isplotted, and other factors. When determination of proportionallimit is required, specify the proced
27、ure and sensitivity of thetest equipment. E63.2.12 slow crack growth (SCG), nsubcritical crackgrowth (extension) which may result from, but is not restrictedto, such mechanisms as environmentally assisted stress corro-sion or diffusive crack growth. C11454. Significance and Use4.1 This test method m
28、ay be used for material development,material comparison, quality assurance, characterization, reli-ability assessment, and design data generation.4.2 Continuous fiber-reinforced ceramic matrix composites(CFCCs) are generally characterized by fine-grain sized(65 % relative humidity (RH) is notrecomme
29、nded.5.2 Surface preparation of test specimens, although nor-mally not considered a major concern in CFCCs, can introducefabrication flaws that may have pronounced effects on com-pressive mechanical properties and behavior (for example,shape and level of the resulting stress-strain curve, compres-si
30、ve strength and strain, proportional limit stress and strain,etc.). Machining damage introduced during test specimenpreparation can be either a random interfering factor in thedetermination of ultimate strength of pristine material (that is,increased frequency of surface-initiated fractures compared
31、 tovolume-initiated fractures), or an inherent part of the strengthcharacteristics to be measured. Surface preparation can alsolead to the introduction of residual stresses. Universal orstandardized test methods of surface preparation do not exist.In addition, the nature of fabrication used for cert
32、ain compos-ites (for example, chemical vapor infiltration or hot pressing)may require the testing of test specimens in the as-processedcondition (that is, it may not be possible to machine the testspecimen faces without compromising the in-plane fiber archi-tecture). Final machining steps may or may
33、 not negate machin-ing damage introduced during the initial machining. Thus,report test specimen fabrication history since it may play animportant role in the measured strength distributions.5.3 Bending in uniaxial compressive tests can introduceeccentricity, leading to geometric instability of the
34、test speci-men and buckling failure before true compressive strength isattained. In addition, if deformations or strains are measured atsurfaces where maximum or minimum stresses occur, bendingmay introduce over or under measurement of strains, depend-ing on the location of the strain measuring devi
35、ce on the testspecimen. Bending can be introduced from, among othersources, initial load train misalignment, misaligned test speci-mens as installed in the grips, warped test specimens, or loadtrain misalignment introduced during testing due to low lateralmachine/grip stiffness.5.4 Fractures that in
36、itiate outside the uniformly stressedgage section of a test specimen may be due to factors such asstress concentrations or geometrical transitions, extraneousstresses introduced by gripping, or strength-limiting features inthe microstructure of the test specimen. Such non-gage sectionfractures will
37、normally constitute invalid tests. In addition, forfrictional face-loaded geometrics, gripping pressure is a keyvariable in the initiation of fracture. Insufficient pressure canshear the outer plies in laminated CFCCs, while too muchpressure can cause local crushing of the CFCC and may initiatefract
38、ure in the vicinity of the grips.5.5 Lateral supports are sometimes used in compressiontests to reduce the tendency of test specimen buckling.However, such lateral supports may introduce sufficient fric-tional stress so as to artificially increase the force required toproduce compressive failure. In
39、 addition, the lateral supportsand attendant frictional stresses may invalidate the assumptionof uniaxial stress state. When lateral supports are used, thefrictional effect should be quantified to ensure that its contri-bution is small, and the means for doing so reported along withthe quantity of t
40、he frictional effect.6. Apparatus6.1 Testing MachinesMachines used for compressive test-ing shall conform to Practices E4. The forces used in deter-mining compressive strength shall be accurate to within 61%at any force within the selected force range of the testingmachine as defined in Practices E4
41、. A schematic showingpertinent features of one possible compressive testing appara-tus is shown in Fig. 1.6.2 Gripping Devices:6.2.1 GeneralVarious types of gripping devices may beused to transmit the measured force applied by the testingmachine to the test specimens. The brittle nature of thematric
42、es of CFCCs requires a uniform interface between theFIG. 1 Schematic Diagram of One Possible Apparatus for Con-ducting a Uniaxially Loaded Compression TestC1358 183grip components and the gripped section of the test specimen.Line or point contacts and nonuniform pressure can produceHertzian-type str
43、esses, leading to crack initiation and fractureof the test specimen in the gripped section.6.2.1.1 The primary recommended gripping system forcompressive testing CFCCs employs active grip interfaces thatrequire a continuous application of a mechanical, hydraulic, orpneumatic force to transmit the fo
44、rce applied by the testmachine to the test specimen. These types of grip interfaces(that is, frictional face-loaded grips) cause a force to be appliednormal to the surface of the gripped section of the testspecimen. Transmission of the uniaxial force applied by thetest machine is then accomplished b
45、y friction between the testspecimen and the grip faces. Thus, important aspects of activegrip interfaces are uniform contact between the gripped sectionof the test specimen and the grip faces and constant coefficientof friction over the grip/specimen interface.6.2.1.2 For flat test specimens, fricti
46、onal face-loaded grips,either by direct lateral pressure grip faces (1)3or by indirectwedge-type grip faces, act as the grip interface (2, 3) asillustrated in Fig. 2 and Fig. 3, respectively. Generally, closetolerances are required for the flatness and parallelism as wellas for the wedge angle of th
47、e wedge grip faces. In addition, thethickness, flatness, and parallelism of the gripped section of thetest specimen must be within similarly close tolerances topromote uniform contact at the test specimen/grip interface.Tolerances will vary depending on the exact configuration asshown in the appropr
48、iate test specimen drawings.6.2.1.3 Sufficient lateral pressure must be applied to preventslippage between the grip face and the test specimen. Gripsurfaces that are scored or serrated with a pattern similar to thatof a single-cut file have been found satisfactory. A fineserration appears to be the
49、most satisfactory. Keep the serra-tions clean and well defined but not overly sharp. The lengthand width of the grip faces shall be equal to or greater than therespective length and width of the gripped sections of the testspecimen.6.2.1.4 An alternative recommended gripping system forcompressive testing CFCCs employs passive grip interfacesthat employ lateral supports and loading anvils to transmit theapplied force to the compressive test specimen. The lateralsupports prevent both buckling of the test specimen in the gagesection and splitting and
