EN 15335:2007

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Significance and use
6 Apparatus
   6.1 Vacuum vessel
   6.2 Transducers
   6.3 Carbon fibre-bundle loops
   6.4 Pumping unit
   6.5 Control and evaluation units
   6.6 Balance
   6.7 Micrometer
   6.8 Callipers
7 Test specimens
   7.1 General
   7.2 Shape and dimensions
   7.3 Plane parallelism
   7.4 Number of test specimens
8 Test procedure
   8.1 Test specimen preparation
   8.2 Adjustment of the apparatus
   8.3 Measurement at room temperature
   8.4 Measurement at high temperatures
9 Calculation of results
   9.1 Basic concept
   9.2 How to calculate eigenfrequencies
   9.3 Identification, matching and fitting
   9.4 The two evaluation steps
10 Accuracy of method and errors
11 Test report
Annex A (informative) Example
   A.1 General
   A.2 Measurement
   A.3 First evaluation step
   A.4 Second evaluation step
   A.5 Results
Bibliography

This European Standard specifies the resonant beam method for the determination of the dynamic elastic moduli of fibre reinforced ceramic matrix composites from 20 °C up to 2 000 °C in vacuum or inert atmosphere. The Young´s moduli and the shear moduli for different orientations with respect to the main axes of symmetry of the composite can be obtained.This document applies to ceramic matrix composites with fibre reinforcement: short fibres, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2  x  3) which have at least orthothropic symmetry.NOTE 1Dynamic means that the elastic moduli are determined non-quasistatically, i.e. under adiabatic conditions, as with the ultrasonic method set out in ENV 14186. The elastic moduli determined by this method may not be compared with moduli obtained in an isothermal condition by stressing statically or quasistatically as with EN 658-1, EN 658-2, EN 1892, EN 1893, EN 12290 and EN 12291.NOTE 2The ceramic matrix composites with fibre reinforcement, listed above, are denoted as “composites” in the course of the document.