ASTM_C_1198_-_09_2013.pdf

Designation:C119809(Reapproved 2013)Standard Test Method forDynamic Youngs Modulus,Shear Modulus,and PoissonsRatio for Advanced Ceramics by Sonic Resonance1This standard is issued under the fixed designation C1198;the number immediately following the 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 the determination of the dy-namic elastic properties of advanced ceramics.Specimens ofthese materials possess specific mechanical resonant frequen-cies that are determined by the elastic modulus,mass,andgeometry of the test specimen.Therefore,the dynamic elasticproperties of a material can be computed if the geometry,mass,and mechanical resonant frequencies of a suitable test speci-men of that material can be measured.Dynamic Youngsmodulus is determined using the resonant frequency in theflexural mode of vibration.The dynamic shear modulus,ormodulus of rigidity,is found using torsional resonant vibra-tions.Dynamic Youngs modulus and dynamic shear modulusare used to compute Poissons ratio.1.2 This test method measures the resonant frequencies oftest specimens of suitable geometry by mechanically excitingthem at continuously variable frequencies.Mechanical excita-tion of the bars is provided through the use of a transducer thattransforms a cyclic electrical signal into a cyclic mechanicalforce on the specimen.Asecond transducer senses the resultingmechanical vibrations of the specimen and transforms theminto an electrical signal.The amplitude and frequency of thesignal are measured by an oscilloscope or other means to detectresonant vibration in the desired mode.The resonantfrequencies,dimensions,and mass of the specimen are used tocalculate dynamic Youngs modulus and dynamic shear modu-lus.(See Fig.1)1.3 This test method is specifically appropriate for advancedceramics that are elastic,homogeneous,and isotropic(1).2Advanced ceramics of a composite character(particulate,whisker,or fiber reinforced)may be tested by this test methodwith the understanding that the character(volume fraction,size,morphology,distribution,orientation,elastic properties,and interfacial bonding)of the reinforcement in the testspecimen will have a direct effect on the elastic properties.These reinforcement effects must be considered in interpretingthe test results for composites.This test method is notsatisfactory for specimens that have cracks or voids that aremajor discontinuities in the specimen.Neither is the testmethod satisfactory when these materials cannot be fabricatedin a uniform rectangular or circular cross section.1.4 A high-temperature furnace and cryogenic cabinet aredescribed for measuring the dynamic elastic moduli as afunction of temperature from 195 to 1200C.1.5 Modification of this test method for use in qualitycontrol is possible.A range of acceptable resonant frequenciesis determined for a specimen with a particular geometry andmass.Any specimen with a frequency response falling outsidethis frequency range is rejected.The actual modulus of eachspecimen need not be determined as long as the limits of theselected frequency range are known to include the resonantfrequency that the specimen must possess if its geometry andmass are within specified tolerances.1.6 The procedures in this test method are,where possible,consistent with the procedures of Test Methods C623,C747,and C848.The tables of these test methods have been replacedby the actual formulas from the original references.With theadvent of computers and sophisticated hand calculators,theactual formulas can be easily used and provide greater accu-racy than factor tables.1.7 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.8 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.01 onMechanical Properties and Performance.Current edition approved Aug.1,2013.Published September 2013.Originallyapproved in 1991.Last previous edition approved in 2009 as C1198 09.DOI:10.1520/C1198-09R13.2The boldface numbers given in parentheses refer to a list of references at theend of the text.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 responsibility 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:3C372 Test Method for Linear Thermal Expansion of Porce-lain Enamel and Glaze Frits and Fired Ceramic WhitewareProducts by the Dilatometer MethodC623 Test Method for Youngs Modulus,She