1、Designation: C1292 10C1292 16Standard Test Method forShear Strength of Continuous Fiber-Reinforced AdvancedCeramics at Ambient Temperatures1This standard is issued under the fixed designation C1292; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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 the determination of shear strength of continuous fiber-reinforced
3、 ceramic composites (CFCCs) atambient temperature. The test methods addressed are (1) the compression of a double-notched test specimen to determineinterlaminar shear strength and (2) the Iosipescu test method to determine the shear strength in any one of the material planes oflaminated composites.
4、Test specimen fabrication methods, testing modes (load or displacement control), testing rates (load rate ordisplacement rate), data collection, and reporting procedures are addressed.1.2 This test method is used for testing advanced ceramic or glass matrix composites with continuous fiber reinforce
5、ment havinguni-directional (1-D) or bi-directional (2-D) fiber architecture. This test method does not address composites with (3-D) fiberarchitecture or discontinuous fiber-reinforced, whisker-reinforced, or particulate-reinforced ceramics.1.3 The values stated in SI units are to be regarded as the
6、 standard and are in accordance with IEEE/ASTM SI 10.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of
7、 regulatorylimitations prior to use. Specific hazard statements are given in 8.1 and 8.2.2. Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsD695 Test Method for Compressive Properties of Rigid PlasticsD3846 Test Method for In-Plane Shear Strength of Reinforced PlasticsD
8、3878 Terminology for Composite MaterialsD5379/D5379M Test Method for Shear Properties of Composite Materials by the V-Notched Beam MethodE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE122 Practice for Calculating Sample Size to Estimat
9、e, With Specified Precision, the Average for a Characteristic of a Lot orProcessE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)E691 Practice for Conducting an Int
10、erlaboratory Study to Determine the Precision of a Test MethodIEEE/ASTM SI 10 American National Standard for Use of the International System of Units (SI): The Modern Metric System3. Terminology3.1 Definitions:3.1.1 The definitions of terms relating to shear strength testing appearing in Terminology
11、 E6 apply to the terms used in this testmethod. The definitions of terms relating to advanced ceramics appearing in Terminology C1145 apply to the terms used in thistest method. The definitions of terms relating to fiber-reinforced composites appearing in Terminology D3878 apply to the termsused in
12、this test method. Additional terms used in conjunction with this test method are defined in the following.1 This test method is under the jurisdiction of ASTM Committee C28 on Advanced Ceramics and is the direct responsibility of Subcommittee C28.07 on Ceramic MatrixComposites.Current edition approv
13、ed Dec. 1, 2010Jan. 15, 2016. Published January 2011February 2016. Originally approved in 1995. Last previous edition approved in 20052010as C1292 00C1292 10. (2005). DOI: 10.1520/C1292-10.10.1520/C1292-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer S
14、ervice at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the prev
15、ious version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM In
16、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 advanced ceramicengineered high-performance predominately nonmetallic, inorganic, ceramic material having specificfunctional attributes.3.1.3 continuous fiber-reinforced ceramic matrix composite (C
17、FCC)ceramic matrix composite in which the reinforcing phaseconsists of a continuous fiber, continuous yarn, or a woven fabric.3.1.4 shear failurebreaking force (F)maximum force required to fracture a shear-loaded test specimen.3.1.5 shear strength (F/L2)maximum shear stress that a material is capabl
18、e of sustaining. Shear strength is calculated frombreaking force in shear and shear area.4. Summary of Test Method4.1 This test method addresses two methods to determine the shear strength of CFCCs: (1) the compression test method todetermine interlaminar shear strength of a double-notched test spec
19、imen,3 and (2) the Iosipescu test method to determine the shearstrength in any one of the material planes of laminated CFCCs.44.1.1 Shear Test by Compression Loading of Double-Notched Test SpecimensThe interlaminar shear strength of CFCCs, asdetermined by this method is measured by loading in compre
20、ssion a double-notched test specimen of uniform width. Failure ofthe test specimen occurs by shear between two centrally located notches machined halfway through the thickness and spaced afixed distance apart on opposing faces. Schematics of the test setup and the test specimen are shown in Fig. 1 a
21、nd Fig. 2.4.1.2 Shear Test By the Iosipescu MethodThe shear strength of one of the different material shear planes of laminated CFCCsmay be determined by loading a test specimen in the form of a rectangular flat strip with symmetric centrally located V-notchesusing a mechanical testing machine and a
22、 four-point asymmetric fixture. The loading can be idealized as asymmetric flexure bythe shear and bending diagrams in Fig. 3. Failure of the test specimen occurs by shear between the V-notches. Different testspecimen configurations are addressed for this test method. Schematics of the test setup an
23、d test specimen are shown in Fig. 4 andFig. 5. The determination of shear properties of polymer matrix composites by the Iosipescu method has been presented in TestMethod D5379/D5379M.5. Significance and Use5.1 Continuous fiber-reinforced ceramic composites are candidate materials for structural app
24、lications requiring high degreesof wear and corrosion resistance, and damage tolerance at high temperatures.5.2 Shear tests provide information on the strength and deformation of materials under shear stresses.5.3 This test method may be used for material development, material comparison, quality as
25、surance, characterization, anddesign data generation.5.4 For quality control purposes, results derived from standardized shear test specimens may be considered indicative of theresponse of the material from which they were taken for given primary processing conditions and post-processing heat treatm
26、ents.3 Whitney, J., M., “Stress Analysis of the Double Notch Shear Specimen,” Proceedings of the American Society for Composites, 4th Technical Conference, BlacksburgVirginia, Oct. 35, 1989, Technomic Publishing Co, pp. 325.4 Iosipescu, N., “New Accurate Procedure for Shear Testing of Metals,” Journ
27、al of Materials, 2, 3, Sept. 1967, pp. 537566.FIG. 1 Schematic of Test Fixture for the Double-Notched Compression Test SpecimenC1292 1626. Interferences6.1 Test environment (vacuum, inert gas, ambient air, etc.) including moisture content (for example, relative humidity) mayhave an influence on the
28、measured shear strength. In particular, the behavior of materials susceptible to slow crack growth fracturewill be strongly influenced by test environment and testing rate. Testing to evaluate the maximum strength potential of a materialshall be conducted in inert environments or at sufficiently rap
29、id testing rates, or both, so as to minimize slow crack growth effects.Conversely, testing can be conducted in environments and testing modes and rates representative of service conditions to evaluatematerial performance under those conditions. When testing is conducted in uncontrolled ambient air w
30、ith the intent of evaluatingmaximum strength potential, relative humidity and temperature must be monitored and reported. Testing at humidity levels 65 %RH is not recommended and any deviations from this recommendation must be reported.6.2 Preparation of test specimens, although normally not conside
31、red a major concern with CFCCs, can introduce fabricationflaws which may have pronounced effects on the mechanical properties and behavior (for example, shape and level of the resultingload-displacementforce-displacement curve and shear strength). Machining damage introduced during test specimen pre
32、parationcan be either a random interfering factor in the determination of shear strength of pristine material, or an inherent part of thestrength characteristics to be measured. Universal or standardized test methods of surface preparation do not exist. Final machiningsteps may, or may not negate ma
33、chining damage introduced during the initial machining. Thus, test specimen fabrication historymay play an important role in the measured strength distributions and shall be reported.6.3 Bending in uniaxially loaded shear tests can cause or promote nonuniform stress distributions that may alter the
34、desireduniform state of stress during the test.6.4 Fractures that initiate outside the uniformly stressed gagegauge section of a test specimen may be due to factors such aslocalized stress concentrations, extraneous stresses introduced by improper loading configurations, or strength-limiting feature
35、s inthe microstructure of the specimen. Such non-gagenon-gauge section fractures will normally constitute invalid tests.NOTE 1All tolerances are in millimetres.millimeters.FIG. 2 Schematic of Double-Notched Compression Test SpecimenC1292 1636.5 For the conduction of the Iosipescu test, thin test spe
36、cimens (width to thickness ratio of more than ten) may suffer fromsplitting and instabilities rendering in turn invalid test results.NOTE 1The loadsforces are depicted as being concentrated, whereas they are actually distributed over an area.FIG. 3 Idealized Force, Shear, and Moment Diagrams for Asy
37、mmetric Four-Point LoadingFIG. 4 Schematic of Test Fixture for the Iosipescu TestC1292 1646.6 For the evaluation of the interlaminar shear strength by the compression of a double-notched test specimen, the distancebetween the notches in the specimen has an effect on the maximum loadforce and therefo
38、re on the shear strength.5 It has been foundthat the stress distribution in the test specimen is independent of the distance between the notches when the notches are far apart.However, when the distance between the notches is such that the stress fields around the notches interact, the measured inte
39、rlaminarshear strength increases. Because of the complexity of the stress field around each notch and its dependence on the properties andhomogeneity of the material, it is recommended to conduct a series of tests on test specimens with different spacing between thenotches to determine their effect
40、on the measured interlaminar shear strength.6.7 For the evaluation of the interlaminar shear strength by the compression of a double-notched test specimen, excessiveclamping force with the jaws will reduce the stress concentration around the notches and therefore artificially increase themeasured in
41、terlaminar shear strength. Because the purpose of the jaws is to maintain the specimen in place and to prevent buckling,avoid overtightening the jaws.6.8 Most test fixtures incorporate an alignment mechanism in the form of a guide rod and a linear roller bearing. Excessive freeplay or excessive fric
42、tion in this mechanism may introduce spurious moments that will alter the ideal loading conditions.7. Apparatus7.1 Testing MachinesThe testing machine shall be in conformance with Practices E4. The forces used in determining shearstrength shall be accurate within 61 % at any force within the selecte
43、d force range of the testing machine as defined in PracticesE4.7.2 Data AcquisitionAt the minimum, autographic records of applied force and cross-head displacement versus time shall beobtained. Either analog chart recorders or digital data acquisition systems may be used for this purpose although a
44、digital recordis recommended for ease of later data analysis. Ideally, an analog chart recorder or plotter shall be used in conjunction with the5 Lara-Curzio, E., “Properties of Continuous Fiber-Reinforced Ceramic Matrix Composites for Gas Turbine Applications,” Chapter 22, in Ceramic Gas Turbine De
45、signand Test Experience: Progress in Ceramic Gas Turbine Development, Vol. 2, Ed. M. van Roode, M. K. Ferber, and D. W. Richerson. ASME 2003, pp. 441491.NOTE 1All tolerances are in millimetres.millimeters.FIG. 5 Schematic of the Iosipescu SpecimenC1292 165digital data acquisition system to provide a
46、n immediate record of the test as a supplement to the digital record. Recording devicesmust be accurate to 61 % of full scale and shall have a minimum data acquisition rate of 10 Hz with a response of 50 Hz deemedmore than sufficient.7.3 Dimension-Measuring DevicesMicrometers and other devices used
47、for measuring linear dimensions must be accurate andprecise to at least 0.01 mm.7.4 Test Fixtures:7.4.1 Double-notched Compression Test SpecimenThe test fixture consists of a stationary element mounted on a base plate,an element that attaches to the crosshead of the testing machine, and two jaws to
48、fix the test specimen in position. A schematicdescription of the test fixture is shown in Fig. 1.5A supporting jig conforming to the geometry of that shown in Fig. 1 of TestMethod D3846 or Fig. 4 of Test Method D695 may also be used.7.4.2 Iosipescu Test SpecimenThe test fixture shall be a four-point
49、 asymmetric flexure fixture shown schematically in Fig. 4.6This test fixture consists of a stationary element mounted on a base plate, and a movable element capable of vertical translationguided by a stiff post. The movable element attaches to the cross-head of the testing machine. Each element clamps half of thetest specimen into position with a wedge action grip able to compensate for minor width variations of the test specimen. A spanof 13 mm is left unsupported between test fixture halves.An alignment tool is recommended to ensure that the test specime
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