oSIST prEN ISO 20505:2025

SLOVENSKI STANDARD
01-januar-2025
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Mehanske
lastnosti keramičnih kompozitov pri sobni temperaturi - Določevanje medplastne
strižne trdnosti in strižnega modula kompozitov, ojačanih z neprekinjenimi vlakni,
s stiskanjem preizkušancev z dvojnim vrezom in z Iosipescujevim preskusom (ISO
20505:2023)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical
properties of ceramic composites at room temperature - Determination of the
interlaminar shear strength and shear modulus of continuous-fibre-reinforced composites
by the compression of double-notched test pieces and by the Iosipescu test (ISO
20505:2023)
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei Raumtemperatur - Bestimmung der Scherfestigkeit und des
Schubmoduls endlosfaserverstärkter Verbundwerkstoffe durch Druckbeanspruchung von
doppeltgekerbten Proben und durch den Iosipescu-Test (ISO 20505:2023)
Céramiques techniques - Propriétés mécaniques des céramiques composites à
température ambiante - Détermination de la résistance au cisaillement interlaminaire et
du module de cisaillement des composites renforcés par des fibres continues, par la
compression d’éprouvettes à double entaille et par l’essai Iosipescu (ISO 20505:2023)
Ta slovenski standard je istoveten z: prEN ISO 20505
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 20505
Second edition
2023-10
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Mechanical properties of ceramic
composites at room temperature —
Determination of the interlaminar
shear strength and shear modulus
of continuous-fibre-reinforced
composites by the compression of
double-notched test pieces and by the
Iosipescu test
Céramiques techniques — Propriétés mécaniques des céramiques
composites à température ambiante — Détermination de la
résistance au cisaillement interlaminaire et du module de cisaillement
des composites renforcés par des fibres continues, par la compression
d’éprouvettes à double entaille et par l’essai Iosipescu
Reference number
ISO 20505:2023(E)
ISO 20505:2023(E)
© ISO 2023
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Published in Switzerland
ii
ISO 20505:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 4
4.1 General . 4
4.2 Double-notched test . 4
4.3 Iosipescu test . 4
5 Apparatus . 5
5.1 Test machine . 5
5.2 Load train . 5
5.2.1 Generalities . 5
5.2.2 Test fixtures . 6
5.3 Strain gauges for Iosipescu test specimen . 8
5.4 Data acquisition . 9
5.5 Dimension-measuring devices . 9
6 Test specimens . 9
6.1 Double-notched test piece . 9
6.2 Iosipescu test piece . 11
7 Test specimen preparation .12
7.1 Machining and preparation . 12
7.2 Bonding of the gauges . 12
7.3 Number of test specimens .12
8 Test procedures .12
8.1 Displacement rate .12
8.2 Measurement of test specimen dimensions . 13
8.3 Testing technique . 13
8.3.1 Specimen mounting . 13
8.3.2 Measurements . 14
8.4 Test validity . 15
9 Calculation of results .16
9.1 Shear strength . 16
9.1.1 Double-notched test piece . 16
9.1.2 Iosipescu test piece . 16
9.2 Shear strain (Iosipescu test) . 17
9.3 Shear-stress-shear-strain curves . 17
9.4 Elastic shear modulus, pseudo-elastic shear modulus . 17
9.5 Statistics . 18
10 Report .18
Annex A (informative) New materials: verification of shear stress field in the Iosipescu test .20
Bibliography .21
iii
ISO 20505:2023(E)
Foreword
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This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
This second edition cancels and replaces the first edition (ISO 20505:2005), which has been technically
revised.
The main changes are as follows:
— Scope revised to include the possibility of measuring the interlaminar shear modulus through the
use of a gauges-instrumented Iosipescu sample;
— new entries added to Clause 3;
— 5.3 and 7.2 specify requirements on the gauges-instrumented Iosipescu sample;
— 9.3, 9.4 and 9.5 define formulae to determine the shear modulus;
— material orientation added to Figure 2 and Figure 3;
— subclause on test validity added (8.4);
— Table 1 and Table 2 updated;
— Annex A replaced by a method to verify the shear stress field in the Iosipescu test to ensure that that
there are no coupling effects that make this document unsuitable for determining the interlaminar
shear properties of the material;
— minor editorial corrections;
— structure revised;
— symbols and notation modified in accordance with ISO 19634.
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ISO 20505:2023(E)
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