|
SIST-TS CEN/TS 15880:2009
01-september-2009
6RGREQDWHKQLþQDNHUDPLND.HUDPLþQLNRPSR]LWL8JRWDYOMDQMHVWULåQHVLOH
YODNQDPDWULFHSULVREQLWHPSHUDWXUL]PHWRGRSRWLVND SXVKRXWPHWKRG
Advanced technical ceramics - Ceramic composites - Determination of the fibre/matrix
interfacial frictional shear stress at room temperature by a single fibre push-out method
Hochleistungskeramik - Keramische Verbundwerkstoffe - Bestimmung der
Reibschubspannung an der Grenzfläche Faser/Matrix bei Raumtemperatur mit Hilfe des
Einzelfaser-Push-out-Verfahrens
Céramiques techniques avancées - Céramiques composites - Détermination de la
contrainte de frottement en cisaillement à l'interface fibre/matrice à température
ambiante - Méthode d'extraction d'une fibre par indentation
Ta slovenski standard je istoveten z: CEN/TS 15880:2009
ICS:
81.060.30 Sodobna keramika Advanced ceramics
SIST-TS CEN/TS 15880:2009 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST-TS CEN/TS 15880:2009
---------------------- Page: 2 ----------------------
SIST-TS CEN/TS 15880:2009
TECHNICAL SPECIFICATION
CEN/TS 15880
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
May 2009
ICS 81.060.30
English Version
Advanced technical ceramics - Ceramic composites -
Determination of the fibre/matrix interfacial frictional shear stress
at room temperature by a single fibre push-out method
Céramiques techniques avancées - Céramiques Hochleistungskeramik - Keramische Verbundwerkstoffe -
composites - Détermination de la contrainte de frottement Bestimmung der Reibschubspannung an der Grenzfläche
en cisaillement à l'interface fibre/matrice à température Faser/Matrix bei Raumtemperatur mit Hilfe des Einzelfaser-
ambiante - Méthode d'extraction d'une fibre par indentation Push-out-Verfahrens
This Technical Specification (CEN/TS) was approved by CEN on 27 March 2009 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15880:2009: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15580:2009 (E)
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms, definitions and symbols .4
4 Principle .5
5 Significance and use .7
6 Apparatus .7
7 Test specimens .9
8 Test specimen preparation . 10
8.1 General . 10
8.2 Choice of the thickness of the test specimen . 10
9 Test procedure . 10
9.1 Measurement of the fibre length, L . 10
f
9.2 Fibre selection . 10
9.3 Measurements of fibre dimensions . 11
9.4 Testing technique . 11
10 Test validity . 11
11 Calculations . 11
12 Test report . 12
Annex A (normative) Determination of the fibre length L for wedge and small angle test
f
specimens . 13
A.1 Wedge test specimen . 13
A.2 Small angle test specimen . 13
Bibliography . 15
2
---------------------- Page: 4 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15880:2009 (E)
Foreword
This document (CEN/TS 15880:2009) has been prepared by Technical Committee CEN/TC 184 “Advanced
technical ceramics”, the secretariat of which is held by BSI.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
3
---------------------- Page: 5 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15580:2009 (E)
1 Scope
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).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
CEN/TR 13233:2007, Advanced technical ceramics - Notations and symbols
ISO 3611, Micrometer callipers for external measurements
3 Terms, definitions and symbols
For the purposes of this European Technical Specification, the terms, definitions and symbols given in
CEN/TR 13233:2007 and the following apply.
3.1
fibre perimeter
p
perimeter of the fibre
3.2
length of the fibre
L
f
embedded length of the fibre which is equal to the local thickness of the test specimen
3.3
compressive force
F
compressive force on the fibre
3.4
compressive plateau force
F
plateau
compressive force on the fibre determined at point "d" of the curve
3.5
interfacial frictional shear stress
ττf
ττ
shear stress during fibre sliding through the matrix
3.6
fibre top displacement
δδ
δδ
displacement of the top of the fibre during the test
4
---------------------- Page: 6 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15880:2009 (E)
4 Principle
Tests specimens of specific sizes and geometry are used for the tests. A fibre is pushed through the matrix
using an indentation tester. A compressive force is applied through an indentor at a constant displacement
rate, on top of a single fibre and parallel to fibre axis. The force and the fibre top displacement are measured
and recorded simultaneously (see Figure 1). The dimensions of the fibre pushed shall be determined.
1
2
5
3
4
Key
1 Force
2 Indentor
3 Selected fibre
4 Matrix
5 Displacement
Figure 1 – Schematic diagram illustrating the principle of the test
5
---------------------- Page: 7 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15580:2009 (E)
Y
1
1
1
c
d
1
e
b
a
X
Key
X Displacement
Y Force
Figure 2 — Schematic diagram showing a typical single-fibre push-out behaviour for a ceramic matrix
composite
Figure 2 exhibits the following steps:
a – b elastic fibre deformation,
b initiation of debonding,
b –c region of progressive (stable) debonding and sliding (push-in),
c instability,
c – d unstable debonding,
d initiation of push-out,
d – e progressive push-out: stable extraction of the embedded fibre (plateau).
The interfacial parameters are extracted from the experimental force versus top-fibre displacement curve. The
complete curve “a-e” is obtained by a push-out test, and the interfacial characteristics are determined using
the plateau force “d-e”.
6
---------------------- Page: 8 ----------------------
SIST-TS CEN/TS 15880:2009
CEN/TS 15880:2009 (E)
5 Significance and use
Ceramic matrix composites display a non-brittle behaviour under tensile loading conditions when the
fibre/matrix bond is carefully designed. The fibre/matrix bond cannot be too strong, otherwise the composite
will be brittle. The fibre/matrix bond cannot be too weak, otherwise the composite will be unable to withstand
high stresses. Interfaces must exhibit an appropriate resistance to cracking to allow, first, matrix crack arrest
and damage tolerance, and second, load transfers from the fibre to the matrix. Characteristics fibre/matrix
interfaces are therefore of primary importance in composite engineering, evaluation and in predictions of
behaviour and performances.
Fibre pushing tests (and more particularly the single fibre push-out tests) are used for the determination of
fibre/matrix interface characteristics in composites. This is a po
...