CEN/TS 820-5:2004

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Method A: Static bending method
  4.1 Principle
  4.2 Apparatus
  4.3 Test pieces
  4.4 Procedure
  4.5 Calculation of results
  4.6 Accuracy and interferences
5 Method B: Resonance method
  5.1 Principle
  5.2 Apparatus
  5.3 Test pieces
  5.4 Procedure
  5.5 Calculation of results
  5.6 Accuracy and interferences
6 Method C: Impulse excitation method
  6.1 Principle
  6.2 Apparatus
  6.3 Test pieces
  6.4 Procedure
  6.5 Calculation
  6.6 Accuracy and interferences
7 Test report
Bibliography

This part of ENV 820 describes methods for determining the elastic moduli, specifically Young's modulus, shear modulus and Poisson's ratio, of advanced monolithic technical ceramics at temperatures above room temperature. The Technical Specification prescribes three alternative methods for determining some or all of these three parameters:AThe determination of Young's modulus by static flexure of a thin beam in three- or four-point bending.BThe determination of Young's modulus by forced longitudinal resonance, or Young's modulus, shear modulus and Poisson's ratio by forced flexural and torsional resonance, of a thin beam.CThe determination of Young's modulus from the fundamental natural frequency of a struck bar (impulse excitation method).This Technical Specification extends the above-defined room-temperature methods described in ENV 843-2 to elevated temperatures. All the test methods assume the use of homogeneous test pieces of linear elastic materials. The test assumes that the test piece has isotropic elastic properties. At high porosity levels all of the methods can become inappropriate. The maximum grain size (see EN 623-3), excluding deliberately added whiskers, should be less than 10% of the minimum dimension of the test piece.