CEN/TC 184/SC 1 - Ceramic composites

This document describes procedures for determination of the compressive behaviour of ceramic matrix composite materials with continuous fibre reinforcement at room temperature. This method applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bi-directional (2D) and tri-directional (xD, with 2 < x < 3), tested along one principal axis of reinforcement or off axis conditions. This method also applies to carbon-fibre-reinforced carbon matrix composites (also known as carbon/carbon or C/C). Two cases of testing are distinguished: compression between platens and compression using grips.

This document describes the flash method for the determination of thermal diffusivity of ceramic matrix composites with continuous fibre reinforcement.
In order to conform with the unidimensional heat transfer hypothesis, the experimental conditions are defined such that the material behaves in a homogeneous manner. This involves performing tests in one symmetry axis of the composite.
The method is applicable to materials which are physically and chemically stable during the measurement, and covers the range of temperature from 100 K to 2 800 K. It is suitable for the measurement of thermal diffusivity values in the range 10−4 m2∙s−1 to 10−7 m2∙s−1.

This document specifies methods for the determination of the apparent solid density, bulk density, apparent porosity and geometric bulk density of fine ceramics, including all ceramic matrix composites.
Two methods are described and are designated as Methods A and B, as follows:
—     Method A: Determination of bulk density, apparent solid density and apparent porosity by liquid displacement (Archimedes' method).
NOTE 1  This method is not appropriate for the determination of an apparent porosity greater than 10 %. For materials with higher porosity, the accuracy of the measurement might not be satisfactory. This method might also not give a satisfactory open porosity result if it is less than 0,5 %.
NOTE 2  This method is also not suitable for materials which are known to have an average pore size of greater than 600 µm.
—     Method B: Determination of bulk density only, by measurement of geometric dimensions and mass.

This document specifies the conditions for the determination of the distribution of strength and rupture strain of ceramic filaments within a multifilament tow at room temperature by performing a tensile test on a multifilament tow.
This document applies to dry tows of continuous ceramic filaments that are assumed to act freely and independently under loading and exhibit linear elastic behaviour up to failure. The outputs of this method are not to be mixed up with the strengths of embedded tows determined by using ISO 24046[1].
[1] Under preparation.

ISO 17139:2014 describes methods for the determination of linear thermal expansion characteristics of ceramic matrix composite materials up to 2 300 K, and is applicable to 1D, 2D, and nD materials. The method describes general principles of construction, calibration, and operation of the equipment.

ISO 18608:2017 describes a method for the classification of ceramic matrix composite (CMC) materials with respect to their sensitivity to crack propagation using tensile tests on notched specimens with different notch depths. Two classes of ceramic matrix composite materials can be distinguished: materials whose strength is sensitive to the presence of notches and materials whose strength is not affected. For sensitive materials, this document defines a method for determining equivalent fracture toughness.
The parameter, Keq, is defined as the fracture toughness of a homogeneous material which presents the same sensitivity to crack propagation as the ceramic matrix composite material which is being considered. The definition of the Keq parameter offers the possibility to compare ceramic matrix composite materials with other materials with respect to sensitivity to crack propagation.
For notch insensitive materials, the concept of Keq does not apply.
ISO 18608:2017 applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1 D), bidirectional (2 D), and tridirectional (x D, where 2 < x ≤ 3), loaded along one principal axis of reinforcement.

ISO 17138:2014 describes a method for the determination of the flexural strength of ceramic matrix composite materials with continuous fibre reinforcement, under three-point or four-point bend at room temperature. This method applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional xD with (2 < x ≤ 3) as defined in CEN/TR 13233, loaded along one principal axis of reinforcement.

ISO 20323:2018 specifies the conditions for the determination of tensile properties of ceramic matrix composite tubes with continuous fibre-reinforcement at ambient temperature in air atmospheric pressure. This document is specific to the tubular geometries since fibre architecture and specimen geometry factors are distinctly different in composite tubes than in flat specimens.
ISO 20323:2018 provides information on the uniaxial tensile properties and tensile stress-strain response such as tensile strength and strain, tensile elastic modulus and Poisson's ratio. The information may be used for material development, control of manufacturing (quality insurance), material comparison, characterization, reliability and design data generation for tubular components.
ISO 20323:2018 addresses, but is not restricted to, various suggested test piece fabrication methods. It applies primarily to ceramic and/or glass matrix composite tubes with a continuous fibrous-reinforcement: unidirectional (1D filament winding and tape lay-up), bi-directional (2D braid and weave) and tri-directional (xD, with 2 < x < 3), loaded along the tube axis.
Values expressed in this document are in accordance with the International System of Units (SI).
NOTE       In most cases, ceramic matrix composites to be used at high temperature in air are coated with an antioxidation coating.

ISO 19634:2017 defines the symbols to be used to represent physical, mechanical and thermal characteristics, as determined by methods described in relevant ISO publications, for ceramic matrix composites. It is aimed at avoiding confusion in reporting measurements and characteristics of products.
Where possible, the definitions are in accordance with the relevant parts of ISO 80000. In addition, the symbols used in undertaking measurements of these characteristics are also defined.

ISO 19630:2017 specifies the conditions for the determination of tensile properties of single filaments of ceramic fibre such as tensile strength, Young modulus and fracture strain. The method applies to continuous ceramic filaments taken from tows, yarns, braids and knittings, which have strain to fracture less than or equal to 5 %.
The method does not apply to carbon fibres that exhibit nonlinear stress-strain curve. The method does not apply to checking the homogeneity of strength properties of fibres, nor to assessing the effects of volume under stress. Statistical aspects of filament failure are not included.

ISO 19628:2017 describes two methods for the determination of the specific heat capacity of ceramic matrix composites with continuous reinforcements (1D, 2D, 3D).
Unidirectional (1D), bi-directional (2D) and tridirectional (XD, with 2 < x ≤ 3).
The two methods are:
-      method A: drop calorimetry;
-      method B: differential scanning calorimetry.
They are applicable from ambient temperature up to a maximum temperature, depending on the method: method A can be used up to 2 250 K, while method B is limited to 1 900 K.
NOTE          Method A is limited to the determination of an average value of the specific heat capacity over a given temperature range and can give a larger spread of results.

ISO 18610:2016 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.
It 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 wavelength used is larger than the thickness of the representative elementary volume, thus imposing an upper limit to the frequency range of the transducers used.

ISO 14544:2013 specifies the conditions for determination of compression properties of ceramic matrix composite materials with continuous fibre reinforcement for temperatures up to 2 000 °C.
ISO 14544:2013 applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x ≤ 3), loaded along one principal axis of reinforcement.

ISO 14574:2013 specifies the conditions for determination of tensile properties of ceramic matrix composite materials with continuous fibre reinforcement for temperatures up to 2 000 °C.
ISO 14574:2013 applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bi-directional (2D), and tri-directional (xD, with 2 < x ≤ 3), loaded along one principal axis of reinforcement.

ISO 17161:2014 describes a procedure to verify the degree of misalignment of the load train of the test machines using a reference test specimen uniformly loaded in tension or in compression, and to give indications in order to correct defects such as torsion and bending.
ISO 17161:2014 is not intended to provide a quantitative and acceptable limit before the testing of ceramic matrix composites with a fibre reinforcement: unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x ≤ 3) loaded along one principal axis of reinforcement. This limit depends on the sensitivity of each type of composite to the misalignment defect.

ISO 17142:2014 specifies the conditions for the determination of properties at constant-amplitude of load or strain in uniaxial tension/tension or in uniaxial tension/compression cyclic fatigue of ceramic matrix composite materials (CMCs) with fibre reinforcement for temperature up to 1 700 °C in air at atmospheric pressure.
It applies to all ceramic matrix composites with fibre reinforcement, unidirectional (1D), bi-directional (2D), and tri-directional (xD, where 2 < x ≤ 3).
Its purpose is to determine the behaviour of CMC when subjected to mechanical fatigue and oxidation simultaneously. Tests for the determination of fatigue properties at high temperature in inert atmospheres differ from those in oxidative atmospheres. Contrary to an inert atmosphere, damage in an oxidative atmosphere accumulates due to the influence of purely mechanical fatigue and to chemical effects of the material's oxidation.

ISO 17140:2014 specifies the conditions for the determination of properties at constant-amplitude of load or strain in uniaxial tension/tension or in uniaxial tension/compression cyclic fatigue of ceramic matrix composite materials (CMCs) with fibre reinforcement at room temperature.
It applies to all ceramic matrix composites with fibre reinforcement, unidirectional (1D), bi-directional (2D), and tri-directional (xD, where 2 < x ≤ 3).

This European Standard specifies the conditions for the determination of the tensile creep deformation and failure behaviour of single filaments of ceramic fibres at high temperature and under test conditions that prevent changes to the material as a result of chemical reaction with the test environment.
This European Standard applies to continuous ceramic filaments taken from tows, yarns, braids and knittings, which have strains to fracture less than or equal to 5 %.

This European standard specifies the conditions, apparatus and procedure for determining the distribution of tensile strength and tensile strain to failure of ceramic filaments in multifilament tows at high temperature in air, vacuum or a controlled inert atmosphere.
This part of EN 1007 applies to tows of continuous ceramic filaments, which are assumed to act freely and independently under loading and behave linearly elastic up to failure.
Two methods are proposed depending on the temperature of the ends of the tow:
a)   hot end method;
NOTE 1   The application of the hot end method is restricted by ceramic glues with sufficient shear strengths at the test temperature. Current experience with this technique is limited to 1 300 °C, because of the maximum application temperature of ceramic glues.
b)   cold end method.
NOTE 2   The cold-end method is limited to 1 700 °C in air and 2 000 °C in inert atmosphere because of the limits of furnaces.
Both methods allow for a failure rate in the determination of distribution of tensile strain and tensile strength.

This CEN Technical Specification specifies a method to determine the fibre-matrix bonding characteristics of
ceramic matrix composite materials at room temperature, by the measurement of the interfacial frictional
shear stress obtained by cycled tension on mini-composites.
A mini-composite is a unidirectional composite reinforced with a single tow.

This CEN Technical Specification specifies a single fibre push-out method to determine the fibre-matrix
bonding characteristics of ceramic matrix composite materials at room temperature, by the measurement of
the interfacial frictional shear stress.
This standard applies to all continuous fibre-reinforced ceramic matrix composites whatever the type of
reinforcement: unidirectional (1D), bidirectional (2D) and tridirectional (xD, with 2 < x ≤ 3).

This Technical Specification specifies the conditions for the determination of the thermal diffusivity of single filaments of ceramic fibres parallel to the fibre axis.
This Technical Specification applies to continuous ceramic filaments taken from tows, yarns, braids and knittings.
The experimental conditions are such that the material behaves in an homogeneous manner and that the heat transfer occurs only by thermal conduction.
The method is applicable to materials which are physically and chemically stable during the measurement, and covers the range of temperature between 100 K and 600 K. It is suitable for the measurement of thermal diffusivity values in the range between 10-4 m²·s-1 and 10-7 m2·s-1.

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 1   Dynamic 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 2   The ceramic matrix composites with fibre reinforcement, listed above, are denoted as “composites” in the course of the document.

This European Standard specifies the conditions for measurement of tensile properties of single filament of ceramic fibres at high temperatures in air or inert atmosphere (vacuum or controlled atmosphere). The method applies to continuous ceramic filaments taken from tows, yarns, staple fibre, braids and knitting, that have strain to fracture less or equal to 5 % and show linear elastic behaviour to fracture.
The method does not apply to testing for homogeneity of strength properties of fibres, nor does it assess the effects of volume under stress. Statistical aspects of fibre failure are not included.
Two methods are proposed depending on the temperature of the filament end:
   Hot end method: this method allows determination of tensile strength, of Young's modulus and of the stress strain curve.
NOTE 1   Current experience with this technique is limited to 1 300 °C, because of the application temperature of ceramic glue.
   Cold end method.
NOTE 2   This method is limited to 1 700 °C in air and 2 000 °C in inert atmosphere because of the limits of furnaces.

This Technical Specification specifies the conditions for the determination of the tensile creep deformation and failure behaviour of single filaments of ceramic fibres at high temperature and under test conditions that prevent changes to the material as a result of chemical reaction with the test environment.
This Technical Specification applies to continuous ceramic filaments taken from tows, yarns, braids and knitted structures, that have strains to failure less than or equal to 5 %.

This European Standard specifies the conditions for the determination of the tensile creep deformation and failure behaviour of ceramic matrix composite materials with continuous fibre reinforcement for temperatures up to 2 000 °C under vacuum or in a gas atmosphere which is inert to the material under test. The purpose of these test conditions is to prevent changes to the material as a result of chemical reaction with the test environment.
This European Standard applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1 D), bidirectional (2 D), and tridirectional (x D, where 2  x  3), loaded along one principal axis of reinforcement.

This European Standard specifies the conditions for the determination of constant-amplitude of load or strain in uniaxial tension/tension or in uniaxial tension/compression cyclic fatigue properties of ceramic matrix composite materials (CMCs) with fibre reinforcement for temperature up to 2 000 °C under vacuum or a gas atmosphere which is inert to the material under test.
NOTE   Test environments are specified which are intended to prevent the material under test from chemically reacting with them.
This European Standard applies to all ceramic matrix composites with fibre reinforcement, unidirectional (1D), bi-directional (2D), and tri-directional (xD, where 2 < x  3).

This European Standard specifies the conditions for the determination of the in-plane shear properties at ambient temperature of ceramic matrix composite materials with continuous fibre reinforcement.
This European Standard applies to ceramic matrix composites with a continuous fibre reinforcement, bi-directional (2D) and tri-directional (xD, with 2 < x < 3).

This document specifies the conditions for determination of the inter-laminar shear strength of ceramic matrix composite materials with continuous fibre reinforcement for temperatures up to 2 000 °C under a vacuum, or a gas atmosphere, which is inert to the material under test, by loading of notched specimens in compression.
NOTE 1   The use of a vacuum or a gas atmosphere is aimed at avoiding changes of the material to be tested due to chemical reaction with its environment during the test.
This document applies to all ceramic matrix composites with continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x < 3), loaded along one principal axis of reinforcement.
NOTE 2   Care should be exercised in interpreting the results of the test method to obtain absolute values of the inter-laminar shear strength of ceramic matrix composites for design purposes.
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This part of EN 658 specifies the conditions for the determination of the interlaminar shear strength matrix composite materials with continuous fibre reinforcement at ambient temperature, by loading a notched specimen in compression. The method applies to unidirectionally and bidirectionally reinforced ceramic matrix composites, as well as to tridirectional composites with weak reinforcement in the third direction.

This part of EN 658 specifies the conditions for the determination of the interlaminar shear strength matrix composite materials with continuous fibre reinforcement at ambient temperature, by subjecting a test specimen to a short-span, three points, bend test. The method applies to unidirectionally and bidirectionally reinforced ceramic matrix composites, as well as to tridirectional composites with weak reinforcement in the third direction.

This part of EN 1007 specifies a method for the determination of the linear density (mass per unit length) of ceramic fibres, including silicon carbide, silicon nitride, silicon carbon-nitride, alumino-silicate, alumina or silicon oxide fibres. The linear density is determined on unsized ceramic yarn.

This part of EN 1007 specifies a method for the determination of the size content of ceramic fibres, including silicon carbide, silicon nitride, silicon carbon-nitride, alumino-silicate, alumina or silicon oxide fibres.

This part of EN 1007 specifies three methods for the determination of the diameter and cross-section area of ceramic single filament, as used in fibre reinforcement of ceramic composites. Note: The cross-sectional area of filaments from different suppliers will vary significantly. The term "diameter" applies both to circular cross-section ("true diameter") and non-circular cross-sections ("apparent diameter").

This part of EN 658 specifies the conditions for determination of tensile properties of ceramic matrix composite materials with continuous fibre reinforcement at ambient temperature. This standard applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D) and tridirectional (xD, with 2

This document specifies the conditions for the determination of the distribution of strength and rupture strain of ceramic filaments within a multifilament tow at room temperature by performing a tensile test on a multifilament tow.
This document applies to dry tows of continuous ceramic filaments that are assumed to act freely and independently under loading and exhibit linear elastic behaviour up to failure. The outputs of this method are not to be mixed up with the strengths of embedded tows determined by using ISO 24046[1].
[1] Under preparation.

This document describes procedures for determination of the tensile behaviour of ceramic matrix composite materials with continuous fibre reinforcement at elevated temperature in air, vacuum and inert gas atmospheres.
This method applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bidirectional (2D) and multi-directional (xD, with x > 2), tested along one principal axis of reinforcement or off axis conditions for 2D and xD materials.
This method also applies to carbon-fibre-reinforced carbon matrix composites (also known as carbon/carbon or C/C).
NOTE  In most cases, ceramic matrix composites to be used at high temperature in air are coated with an anti-oxidation coating.

This document describes procedures for determination of the compressive behaviour of ceramic matrix composite materials with continuous fibre reinforcement at elevated temperature in air, vacuum and inert gas atmospheres.
This method applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bidirectional (2D) and multi-directional (xD, with x > 2), tested along one principal axis of reinforcement or off axis conditions for 2D and xD materials.
This method also applies to carbon-fibre-reinforced carbon matrix composites (also known as carbon/carbon or C/C).
Two cases of testing are distinguished: compression between platens and compression using grips.

TThis document specifies the conditions for determination of the flexural strength of ceramic matrix composite materials with continuous fibre reinforcement under three-point or four-point bending for temperatures up to 2 000 °C under vacuum or a gas atmosphere which is inert to the material under test.
NOTE 1   The use of these environments is aimed at avoiding changes of the material affecting its flexural strength caused by chemical reaction with its environment during the test.
This European document applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x £ 3), loaded along one principal axis of reinforcement.
NOTE 2   The method outlined in this document should not be used to obtain values of flexural strength for design purposes.

This document describes a method for the determination of the thermal conductivity of ceramic matrix composites with continuous fibre reinforcement. This method applies to all ceramic matrix composites with a fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 < x <= 3) as defined in ENV 13233, submitted to a heat flux along one principal axis of anisotropy.
The experimental conditions are such that the material behaves in an homogeneous manner for each of its axis of anisotropy and that the heat transfer occurs only by thermal conduction. The method is applicable to materials which are physically and chemically stable during the measurement.
Contrary to other methods of direct measurement which permit only to determine a value of the thermal conductivity averaged over an interval of temperature, the method described in this document, based on an adequate exploitation of the temperature record, allows to determine with a good accuracy the thermal conductivity at a defined temperature. This is more interesting since the variation of the thermal conductivity with the temperature is non-linear, which is generally the case for CMC's.
NOTE   It is also possible to calculate the conductivity of CMC's by an indirect method using the following equation:
y = a  x pb x Cp
where
y   is the thermal conductivity;
a   is the thermal diffusivity;
pb   is the bulk density;
Cp   is the specific heat capacity.

This standard specifies the conditions for determination of the flexural strength of ceramic matrix composite materials with continuous fibre reinforcement under three-point or four-point bending for temperatures up to 1700°C in air at atmospheric pressure. This Prestandard applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2

This document describes procedures for determination of the compressive behaviour of ceramic matrix composite materials with continuous fibre reinforcement at room temperature. This method applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bi-directional (2D) and tri-directional (xD, with 2 < x < 3), tested along one principal axis of reinforcement or off axis conditions. This method also applies to carbon-fibre-reinforced carbon matrix composites (also known as carbon/carbon or C/C). Two cases of testing are distinguished: compression between platens and compression using grips.

This European Standard specifies the conditions, apparatus and procedure for determining the distribution of tensile strength and tensile strain to failure of ceramic filaments in multifilament tows at ambient temperature.
This European Standard applies to tows of continuous ceramic filaments, which are assumed to act freely and independently under loading, and behave linearly elastic up to failure.

This European Standard describes two methods for determination of the bulk density and apparent porosity of ceramic matrix composites with fibrous continuous reinforcement (1D, 2D, 3D). Two methods are described and are designated as Methods A and B, as follows : - Method A: Determination of bulk density only, by measurement of dimensions and mass ; - Method B: Determination of bulk density and apparent porosity by liquid displacement.

This part of EN 1159 describes the laser flash method for the determination of thermal diffusivity of ceramic matrix composites with continuous reinforcements (1D, 2D, 3D). The experimental conditions are such that the material behaves in an homogeneous manner for each of its axes of anisotropy and that the heat transfer occurs only by thermal conduction. The method is applicable to materials which are physically and chemically stable during the measurement, and covers the range of temperature between 100 K and 2 800 K.

DIN - Correction of Equation 5 and numbering of equations

This European Standard describes a method for the classification of ceramic matrix composite (CMC) materials with respect to their sensitivity to crack propagation using tensile tests on notched specimens with different notch depths. Two classes of ceramic matrix composite materials can be distinguished: materials whose strength is sensitive to the presence of notches and materials whose strength is not affected. For sensitive materials, this European Standard defines a method for determining equivalent fracture toughness.
The parameter, Keq, is defined as the fracture toughness of a homogeneous material which presents the same sensitivity to crack propagation as the ceramic matrix composite material which is being considered. The definition of the Keq parameter offers the possibility to compare ceramic matrix composite materials with other materials with respect to sensitivity to crack propagation.
For notch insensitive materials, the concept of Keq does not apply.
This European Standard applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1 D), bidirectional (2 D), and tridirectional (x D, where 2 < x ≤ 3), loaded along one principal axis of reinforcement.

This Part of EN 1159 describes methods for the determination of linear thermal expansion characteristics of ceramic matrix composite materials up to 2 300 K, and is applicable to 10, 2D and nD materials.
The method describes general principles of construction calibration and operation of the equipment.

This part of EN 658 specifies the conditions for the determination of the flexural strength of ceramic matrix composite materials with continuous fibre reinforcement, under three-point or four-point bending at ambient temperature. This standard applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional xD with (2 < x <= 3), loaded along one principal axis of reinforcement.

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.