1、Designation: C1358 11Standard 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 monotonicuniaxial loading of continuous fiber-reinforced advanced ce-ramics at ambient temperatures. This test method addresses,but is not restricted to, various suggested test specimengeometries as listed in the appe
4、ndix. In addition, test specimenfabrication methods, testing modes (force, displacement, orstrain control), testing rates (force rate, stress rate, displace-ment rate, or strain rate), allowable bending, and data collec-tion and reporting procedures are addressed. Compressivestrength as used in this
5、 test method refers to the compressivestrength obtained under monotonic uniaxial loading wheremonotonic refers to a continuous nonstop test rate with noreversals from test initiation to final fracture.1.2 This test method applies primarily to advanced ceramicmatrix composites with continuous fiber r
6、einforcement: uni-directional (1D), bi-directional (2D), and tri-directional(3D) or other multi-directional reinforcements. In addition,this test method may also be used with glass (amorphous)matrix composites with 1D, 2D, 3D, and other multi-directional continuous fiber reinforcements. This test me
7、thoddoes not directly address discontinuous fiber-reinforced,whisker-reinforced, or particulate-reinforced ceramics, al-though the test methods detailed here may be equally appli-cable to these composites.1.3 The values stated in SI units are to be regarded as thestandard and are in accordance with
8、SI 10-02 IEEE/ASTM SI10 .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 and health practices and determine the applica-bility of regulatory limitations pri
9、or to use. Refer to Section 7for specific precautions.2. Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsD695 Test Method for Compressive Properties of RigidPlasticsD3379 Test Method for Tensile Strength and YoungsModulus for High-Modulus Single-Filament MaterialsD3410/
10、D3410M Test Method for Compressive Propertiesof Polymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3479/D3479M Test Method for Tension-Tension Fatigueof Polymer Matrix Composite MaterialsD3878 Terminology for Composite MaterialsE4 Practices for Force Verification of Tes
11、ting MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE337 Test Method for Measuring Humidity with a Psy-chrometer (the Measurement of Wet- and Dry-Bulb Tem-peratures)E1012 Practice for Verification of Test Frame
12、 and SpecimenAlignment Under Tensile and Compressive Axial ForceApplicationSI 10-02 IEEE/ASTM SI 10 American National Standardfor Use of the International System of Units (SI): TheModern Metric System3. Terminology3.1 Definitions:3.1.1 The definitions of terms relating to compressive test-ing, advan
13、ced ceramics, and fiber-reinforced composites, ap-pearing in Terminology E6, Test Method D695, PracticeE1012, Terminology C1145, Test Method D3410/D3410M,and Terminology D3878 apply to the terms used in this testmethod. Pertinent definitions are shown as follows with theappropriate source given in p
14、arentheses.Additional terms usedin conjunction with this test method are defined in 3.2.1This test method is 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 15, 2011. Pu
15、blished August 2011. Originallyapproved in 1996. Last previous edition approved in 2005 as C1358 05. DOI:10.1520/C1358-112For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe
16、r to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This Standard:3.2.1 advanced ceramic, nhighly engineered, high-performance predominantly
17、 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 two strain-sensingdevices located at the mid length of the reduc
18、ed 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 breaking force F, nforce at which fracture occurs.E63.2.5 ceramic matr
19、ix 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-ceramic, glass, metal, or organic innature. These components ar
20、e 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 capable of sustaining. Compres-sive strength is calculated from the
21、 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 phase consists of a continuous fiber, continuous yarn, or awoven f
22、abric.3.2.8 gage length L, noriginal length of that portion ofthe specimen over which strain or change of length is deter-mined. E63.2.9 modulus of elasticity FL2, nratio of stress tocorresponding strain below the proportional limit. E63.2.10 proportional limit stress in compression FL2,ngreatest st
23、ress that a material is capable of sustainingwithout any deviation from proportionality of stress to strain(Hookes law).3.2.10.1 DiscussionMany experiments have shown thatvalues observed for the proportional limit vary greatly with thesensitivity and accuracy of the testing equipment, eccentricityof
24、 loading, the scale to which the stress-strain diagram isplotted, and other factors. When determination of proportionallimit is required, specify the procedure and sensitivity of thetest equipment. E63.2.11 percent bending, nbending strain times 100 di-vided by the axial strain. E10123.2.12 slow cra
25、ck 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 may be used for material development,material comparison, qu
26、ality 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 notrecommended.5.2 Surface preparation of test specimens, although n
27、or-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-sive strength and strain, proportional limit stress and stra
28、in,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 tovolume-initiated fractures), or an inherent part of the
29、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 certain compos-ites (for example, chemical vapor infiltration o
30、r 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 not, negatemachining damage introduced during the initial
31、 machining.Thus, report test specimen fabrication history since it may playan important role in the measured strength distributions.5.3 Bending in uniaxial compressive tests can introduceeccentricity leading to geometric instability of the test speci-men and buckling failure before true compressive
32、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 dependingon the location of the strain-measuring device on the testspecimen. Bending can be introduced from, among o
33、thersources, 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 initiate outside the uniformly stressedgage section of a test spe
34、cimen 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 normally constitute invalid tests. In addition, forfrictional f
35、ace-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 initiatefracture in the vicinity of the grips.5.5 Lateral supports are somet
36、imes used in compressiontests to reduce the tendency of test specimen buckling. How-ever, such lateral supports may introduce sufficient frictionalstress so as to artificially increase the force required to producecompressive failure. In addition, the lateral supports andattendant frictional stresse
37、s may invalidate the assumption ofuniaxial 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 the frictional effect.6. Apparatus6.1 Testing Machines Machines
38、used for compressivetesting shall conform to Practices E4. The forces used indetermining compressive strength shall be accurate within61 % at any force within the selected force range of the testingmachine as defined in Practices E4. A schematic showingpertinent features of one possible compressive
39、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 thematrices of CFCCs requires a uniform interface between thegrip components
40、and the gripped section of the test specimen.Line or point contacts and nonuniform pressure can produceHertzian-type stresses leading to crack initiation and fracture ofthe test specimen in the gripped section.6.2.1.1 The primary recommended gripping system forcompressive testing CFCCs employs activ
41、e grip interfaces thatrequire a continuous application of a mechanical, hydraulic, orpneumatic force to transmit the force 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 gr
42、ipped section of the testspecimen. Transmission of the uniaxial force applied by thetest machine is then accomplished by friction between the testspecimen and the grip faces. Thus, important aspects of activegrip interfaces are uniform contact between the gripped sectionFIG. 1 Schematic Diagram of O
43、ne Possible Apparatus forConducting a Uniaxially-Loaded Compression TestC1358 113of the test specimen and the grip faces and constant coefficientof friction over the grip/specimen interface.6.2.1.2 For flat test specimens, frictional face-loaded grips,either by direct lateral pressure grip faces (1)
44、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 the wedge grip faces. In addition, thethickness, flatness, and parallelism
45、 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 appropriate test specimen drawings.6.2.1.3 Sufficient lateral pressure must be
46、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 most satisfactory. Keep the serra-tions clean and well-defined but not o
47、verly 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 interfaceswhich employ lateral supports
48、 and loading anvils to transmitthe applied force to the compressive test specimen. The lateralsupports prevent both buckling of the test specimen in the gagesection and splitting and brooming of the 8grip section.Transmission of the force applied by the test machine is thenaccomplished by a directly
49、 applied uniaxial force to the testspecimen ends. Thus, important aspects of this type of gripinterface are uniform contact between the loading anvil and thetest specimen and good contact between the test specimen andlateral supports.6.2.1.5 For flat test specimens, a controlled, face-supportedfixture (4) as illustrated in Fig. 4 can be used. Generally, closetolerances are required for the flatness and parallelism. Inaddition, the thickness, flatness, and parallelism of the sup-ported section of the test specimen must be within similarlyclo
