ASTM_C_1259_-_15.pdf

Designation:C125915Standard Test Method forDynamic Youngs Modulus,Shear Modulus,and PoissonsRatio for Advanced Ceramics by Impulse Excitation ofVibration1This standard is issued under the fixed designation C1259;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 determination of the dynamicelastic properties of advanced ceramics at ambient tempera-tures.Specimens of these materials possess specific mechani-cal resonant frequencies that are determined by the elasticmodulus,mass,and geometry of the test specimen.Thedynamic elastic properties of a material can therefore becomputed if the geometry,mass,and mechanical resonantfrequencies of a suitable(rectangular,cylindrical,or discgeometry)test specimen of that material can be measured.Dynamic Youngs modulus is determined using the resonantfrequency in the flexural mode of vibration.The dynamic shearmodulus,or modulus of rigidity,is found using torsionalresonant vibrations.Dynamic Youngs modulus and dynamicshear modulus are used to compute Poissons ratio.1.2 This test method measures the fundamental resonantfrequency of test specimens of suitable geometry by excitingthem mechanically by a singular elastic strike with an impulsetool.Specimen supports,impulse locations,and signal pick-uppoints are selected to induce and measure specific modes of thetransient vibrations.A transducer(for example,contact accel-erometer or non-contacting microphone)senses the resultingmechanical vibrations of the specimen and transforms theminto electric signals.(See Fig.1.)The transient signals areanalyzed,and the fundamental resonant frequency is isolatedand measured by the signal analyzer,which provides a numeri-cal reading that is(or is proportional to)either the frequency orthe period of the specimen vibration.The appropriate funda-mental resonant frequencies,dimensions,and mass of thespecimen are used to calculate dynamic Youngs modulus,dynamic shear modulus,and Poissons ratio.1.3 Although not specifically described herein,this testmethod can also be performed at cryogenic and high tempera-tures with suitable equipment modifications and appropriatemodifications to the calculations to compensate for thermalexpansion,in accordance with sections 9.2,9.3,and 10.4 ofC1198.1.4 Where possible,the procedures,sample specifications,and calculations in this test method are consistent with TestMethods C623,C747,C848,and C1198.1.5 This test method uses test specimens in bar,rod,anddisc geometries.The rod and bar geometries are described inthe main body.The disc geometry is addressed in Annex A1.1.6 A modification of this test method can be used forquality control and nondestructive evaluation,using changes inresonant frequency to detect variations in specimen geometryand mass and internal flaws in the specimen.(See 5.5).1.7 The values stated in SI units are to be regarded as thestandard.1.8 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 prior to use.2.Referenced Documents2.1 ASTM Standards:2C372 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,Shear Modulus,and Poissons Ratio for Glass and Glass-Ceramics byResonanceC747 Test Method for Moduli of Elasticity and FundamentalFrequencies of Carbon and Graphite Materials by SonicResonanceC848 Test Method for Youngs Modulus,Shear Modulus,and Poissons Ratio For Ceramic Whitewares by Reso-nance1This 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 Feb.1,2015.Published April 2015.Originallyapproved in 1994.Last previous edition approved in 2014 as C1259 14.DOI:10.1520/C1259-15.2For 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 Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 C1145 Terminology of Advanced CeramicsC1161 Test Method for Flexural Strength of AdvancedCeramics at Ambient TemperatureC1198 Test Method for Dynamic Youngs Modulus,ShearModulus,and Poissons Ratio for Advanced Ceramics bySonic ResonanceD4092 Terminology for Plastics:Dynamic MechanicalPropertiesE6 Terminology Relating to Methods of Mechanical TestingE177 Practice for Use of the Terms