BS EN 14186:2007

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Significance and use
6 Apparatus
   6.1 Ultrasonic tank with thermostatic control
   6.2 Temperature measurement device
   6.3 Test specimen holder
   6.4 Transducers
   6.5 Transducer holders
   6.6 Pulse generator
   6.7 Signal recording system
7 Test specimens
8 Test specimen preparation
9 Test procedure
   9.1 Choice of frequency
   9.2 Establishment of the test temperature
   9.3 Reference test without test specimen
   9.4 Measurement with the specimen
10 Calculation
   10.1 Delay
   10.2 Calculation of the propagation velocities
   10.3 Calculation of the refracted angle [theta][r]
   10.4 Identification of the elastic constants, C[ij]
   10.5 Back calculation of the phase velocities
   10.6 Polar plots of the velocity curves
   10.7 Calculation of the quadratic deviation
   10.8 Calculation of the engineering constants
11 Test validity
   11.1 Measurements
   11.2 Criterion of validity for the reliability of
        the C[ij] components
12 Test report
Annex A (informative) - Example of a presentation of the
                        results for a material with
                        orthothropic symmetry
      A.1 Velocity curves
      A.2 Stiffness matrix with stiffness components
      A.3 Engineering constants
Bibliography

Describes an ultrasonic method to determine the components of the elasticity tensor of ceramic matrix composite materials at room temperature.

This European Standard specifies an ultrasonic method to determine the components of the elasticity tensor of ceramic matrix composite materials at room temperature. Young\'s moduli, shear moduli and Poisson coefficients, can be determined from the components of the elasticity tensor. This European Standard applies to ceramic matrix composites with a continuous fibre reinforcement: unidirectional (1D), bidirectional (2D), and tridirectional (?D, with 2 < ? ? 3) which have at least orthotropic symmetry, and whose material symmetry axes are known. This method is applicable only when the ultrasonic wave length used is larger than the thickness of the representative elementary volume, thus imposing an upper limit to the frequency range of the transducers used. NOTE Properties obtained by this method may not be comparable with moduli obtained by EN 658-1, EN 658-2 and EN 12289.