ASTM C1198-08

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation:C 1198–01 Designation:C 1198–08
Standard Test Method for
Dynamic Young’s Modulus, Shear Modulus, and Poisson’s
1
Ratio for Advanced Ceramics by Sonic Resonance
This standard is issued under the fixed designation C 1198; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the dynamic elastic properties of advanced ceramics. Specimens of these
materials possess specific mechanical resonant frequencies that are determined by the elastic modulus, mass, and geometry of the
test specimen. Therefore, the dynamic elastic properties of a material can be computed if the geometry, mass, and mechanical
resonant frequencies of a suitable test specimen of that material can be measured. DynamicYoung’s modulus is determined using
the resonant frequency in the flexural mode of vibration. The dynamic shear modulus, or modulus of rigidity, is found using
torsional resonant vibrations. Dynamic Young’s modulus and dynamic shear modulus are used to compute Poisson’s ratio.
1.2This test method is specifically appropriate for advanced ceramics that are elastic, homogeneous, and isotropic
1.2 This test method measures the resonant frequencies of test specimens of suitable geometry by mechanically exciting them
at continuously variable frequencies. Mechanical excitation of the bars is provided through the use of a transducer that transforms
a cyclic electrical signal into a cyclic mechanical force on the specimen. A second transducer senses the resulting mechanical
vibrations of the specimen and transforms them into an electrical signal. The amplitude and frequency of the signal are measured
byanoscilloscopeorothermeanstodetectresonantvibrationinthedesiredmode.Theresonantfrequencies,dimensions,andmass
of the specimen are used to calculate dynamic Young’s modulus and dynamic shear modulus. (See Fig. 1)
2
1.3 This test method is specifically appropriate for advanced ceramics that are elastic, homogeneous, and isotropic (1).
Advanced ceramics of a composite character (particulate, whisker, or fiber reinforced) may be tested by this test method with the
understanding that the character (volume fraction, size, morphology, distribution, orientation, elastic properties, and interfacial
bonding) of the reinforcement in the test specimen will have a direct effect on the elastic properties. These reinforcement effects
mustbeconsideredininterpretingthetestresultsforcomposites.Thistestmethodisnotsatisfactoryforspecimensthathavecracks
or voids that are major discontinuities in the specimen. Neither is the test method satisfactory when these materials cannot be
fabricated in a uniform rectangular or circular cross section.
1.3A1.4 Ahigh-temperaturefurnaceandcryogeniccabinetaredescribedformeasuringthedynamicelasticmoduliasafunction
of temperature from −195 to 1200°C.
1.45 Modification of this test method for use in quality control is possible. A range of acceptable resonant frequencies is
determined for a specimen with a particular geometry and mass. Any specimen with a frequency response falling outside this
frequency range is rejected. The actual modulus of each specimen need not be determined as long as the limits of the selected
frequency range are known to include the resonant frequency that the specimen must possess if its geometry and mass are within
specified tolerances.
1.5The1.6 Theproceduresinthistestmethodare,wherepossible,consistentwiththeproceduresofTestMethodsC623,C747,
andC848.Thetablesofthesetestmethodshavebeenreplacedbytheactualformulasfromtheoriginalreferences.Withtheadvent
of computers and sophisticated hand calculators, the actual formulas can be easily used and provide greater accuracy than factor
tables.
1.6The1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information
only.
1.71.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1
This test method is under the jurisdiction of ASTM Committee C28 on Advanced Ceramics and is the direct responsibility of Subcommittee C28.01 on Mechanical
Properties and
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