SIST EN ISO 527-4:2022

SLOVENSKI STANDARD
SIST EN ISO 527-4:2022
01-marec-2022
Nadomešča:
SIST EN ISO 527-4:1999
Polimerni materiali - Določanje nateznih lastnosti - 4. del: Preskusni pogoji za
izotropne in ortotropne z vlakni ojačene polimerne kompozite (ISO 527-4:2021)
Plastics - Determination of tensile properties - Part 4: Test conditions for isotropic and
orthotropic fibre-reinforced plastic composites (ISO 527-4:2021)
Kunststoffe - Bestimmung der Zugeigenschaften - Teil 4: Prüfbedingungen für isotrop
und anisotrop faserverstärkte Kunststoffverbundwerkstoffe (ISO 527-4:2021)
Plastiques - Détermination des propriétés en traction - Partie 4 : Conditions d’essai pour
les composites plastiques renforcés de fibres isotropes et orthotropes (ISO 527-4:2021)
Ta slovenski standard je istoveten z: EN ISO 527-4:2021
ICS:
83.120 Ojačani polimeri Reinforced plastics
SIST EN ISO 527-4:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 527-4:2022

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SIST EN ISO 527-4:2022


EN ISO 527-4
EUROPEAN STANDARD

NORME EUROPÉENNE

December 2021
EUROPÄISCHE NORM
ICS 83.120 Supersedes EN ISO 527-4:1997
English Version

Plastics - Determination of tensile properties - Part 4: Test
conditions for isotropic and orthotropic fibre-reinforced
plastic composites (ISO 527-4:2021)
Plastiques - Détermination des propriétés en traction - Kunststoffe - Bestimmung der Zugeigenschaften - Teil
Partie 4 : Conditions d'essai pour les composites 4: Prüfbedingungen für isotrop und anisotrop
plastiques renforcés de fibres isotropes et orthotropes faserverstärkte Kunststoffverbundwerkstoffe (ISO
(ISO 527-4:2021) 527-4:2021)
This European Standard was approved by CEN on 4 October 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 527-4:2021 E
worldwide for CEN national Members.

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SIST EN ISO 527-4:2022
EN ISO 527-4:2021 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 527-4:2022
EN ISO 527-4:2021 (E)
European foreword
This document (EN ISO 527-4:2021) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2022, and conflicting national standards shall be
withdrawn at the latest by June 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 527-4:1997.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 527-4:2021 has been approved by CEN as EN ISO 527-4:2021 without any modification.

3

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SIST EN ISO 527-4:2022

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SIST EN ISO 527-4:2022
INTERNATIONAL ISO
STANDARD 527-4
Second edition
2021-12
Plastics — Determination of tensile
properties —
Part 4:
Test conditions for isotropic and
orthotropic fibre-reinforced plastic
composites
Plastiques — Détermination des propriétés en traction —
Partie 4: Conditions d'essai pour les composites plastiques renforcés
de fibres isotropes et orthotropes
Reference number
ISO 527-4:2021(E)
© ISO 2021

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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2021 – All rights reserved

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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 5
5 Apparatus . 5
6 Test specimens . 5
6.1 Shape and dimensions . 5
6.2 Preparation of specimens . 9
6.2.1 General . 9
6.2.2 End tabs for type 3 specimens . 9
6.2.3 Applications of end tabs for type 3 specimens . 9
6.3 Gauge marks . 9
6.4 Checking the specimens . 10
6.5 Anisotropy . 10
7 Number of specimens . .10
8 Conditioning .10
9 Procedure .10
9.1 Test atmosphere . 10
9.2 Measurement of specimen dimensions . 10
9.3 Clamping . 11
9.4 Prestresses . . 11
9.5 Setting of extensometers and strain gauges and placing of gauge marks . 11
9.6 Speed of testing . 11
9.6.1 For type 1B test specimens . 11
9.6.2 For type 2, type 3 and type 4 test specimens . 11
9.7 Recording of data . 11
10 Calculation and expression of results .11
10.1 Calculation of all properties for parallel sided specimens . 11
10.2 Failure location related calculation of tensile strength for type 4 specimens .12
11 Precision .12
12 Test report .12
Annex A (informative) Alignment of specimens .13
Annex B (informative) Testing with tapered tensile specimen geometry without tabs (type
4) .15
Annex C (informative) Unbonded tabs or gripping condition without tabs using fine grip
face .18
Annex D (normative) Specimen preparation for type 2 and type 3 .21
Annex E (normative) Failure location related calculation of tensile strength for type 4
specimens .23
Bibliography .27
iii
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13,
Composites and reinforcement fibres, in collaboration with the European Committee for Standardization
(CEN) Technical Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 527-4:1997), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— specimen type 4 (tapered tensile specimen) especially for testing of multidirectional, continuous
fibre-reinforced thermoplastic composites has been implemented;
— gripping force or pressure (e.g. via torque or manometer depending on gripping system used) has
been adjusted;
— the following new annexes have been added:
— Annex C (Unbonded tabs or gripping condition without tabs using fine grip faces),
— Annex B (Testing with tapered tensile specimen geometry without tabs), and
— Annex E (Failure location related calculation of tensile strength for type 4 specimens).
A list of all parts in the ISO 527 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
Introduction
This document introduces a new test specimen, type 4, with a tapered geometry for use without
end tabs. The geometry has been developed to overcome difficulties with bonding end-tabbed test
specimens, especially when testing materials based on a thermoplastic matrix.
Guidance on gripping, including grip face design, is also added.
v
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SIST EN ISO 527-4:2022

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SIST EN ISO 527-4:2022
INTERNATIONAL STANDARD ISO 527-4:2021(E)
Plastics — Determination of tensile properties —
Part 4:
Test conditions for isotropic and orthotropic fibre-
reinforced plastic composites
1 Scope
This document specifies the test conditions for the determination of the tensile properties of isotropic
and orthotropic fibre-reinforced plastic composites, based upon the general principles given in
ISO 527-1.
NOTE 1 Unidirectional reinforced materials are covered by ISO 527-5.
The methods are used to investigate the tensile behaviour of the test specimens and for determining
the tensile strength, tensile modulus, Poisson's ratios and other aspects of the tensile stress-strain
relationship under the defined conditions.
The test method is suitable for use with the following materials:
— fibre-reinforced thermosetting and thermoplastic composites incorporating non-unidirectional
reinforcements such as mats, woven fabrics, woven rovings, chopped strands, combinations of such
reinforcements, hybrids, rovings, short or milled fibres or preimpregnated materials (prepregs);
NOTE 2 Injection moulded specimens are covered by ISO 527-2.
— combinations of the above with unidirectional reinforcements and multidirectional reinforced
materials constructed from unidirectional layers, provided such laminates are symmetrical;
NOTE 3 Materials with completely or mainly unidirectional reinforcements are covered by ISO 527-5.
— finished products made from materials mentioned above.
The reinforcement fibres covered include glass fibres, carbon fibres, aramid fibres and other similar
fibres.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 527-1:2019, Plastics — Determination of tensile properties — Part 1: General principles
ISO 1268 (all parts), Fibre-reinforced plastics — Methods of producing test plates
ISO 2818, Plastics — Preparation of test specimens by machining
ISO 16012, Plastics — Determination of linear dimensions of test specimens
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
1
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
gauge length
L
0
initial distance between the gauge marks on the central part of the test specimen
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: The values of the gauge length that are indicated for the specimen types in the different parts
of ISO 527 represent the maximum relevant gauge length.
[SOURCE: ISO 527-1:2019, 3.1]
3.2
thickness
h
smaller initial dimension of the rectangular cross-section in the central part of a test specimen
Note 1 to entry: It is expressed in millimetres (mm).
[SOURCE: ISO 527-1:2019, 3.2]
3.3
width
b
larger initial dimension of the rectangular cross-section in the central part of a test specimen
Note 1 to entry: It is expressed in millimetres (mm).
[SOURCE: ISO 527-1:2019, 3.3]
3.4
test speed
v
rate of separation of the gripping jaws
Note 1 to entry: It is expressed in millimetres per minute (mm/min).
[SOURCE: ISO 527-1:2019, 3.5]
3.5
stress
σ
normal force per unit area of the original cross-section within the gauge length (3.1)
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: In order to differentiate from the true stress related to the actual cross-section of the specimen,
this stress is frequently called “engineering stress”.
Note 3 to entry: σ for “1"-direction specimens is defined as σ and for "2"-direction specimens as σ (see 3.9 and
1 2
Figure 2 for definitions of these directions).
[SOURCE: ISO 527-1:2019, 3.6, modified — Domain “” and Note 3 to entry has been added.]
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
3.5.1
strength
σ
m
maximum stress observed during a tensile test
Note 1 to entry: It is expressed in megapascals (MPa).
[SOURCE: ISO 527-1:2019, 3.6.2]
3.6
strain
ε
increase in length per unit original length of the gauge
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
[SOURCE: ISO 527-1:2019, 3.7]
3.6.1
strain at strength
ε
m
strain at which the strength (3.5.1) is reached
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
[SOURCE: ISO 527-1:2019, 3.7.3]
3.7
tensile modulus
modulus of elasticity under tension
E
t
slope of the stress/strain curve σ(ε) in the interval between the two strains ε = 0,05 % and ε = 0,25 %
1 2
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: It may be calculated either as the chord modulus or as the slope of a linear least-squares
regression line in this interval.
Note 3 to entry: This definition does not apply to films.
Note 4 to entry: See Figure 1.
[SOURCE: ISO 527-1:2019, 3.9]
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
Key
X strain, ε
Y stress, σ
a slope E
Figure 1 — Stress-strain curve
3.8
Poisson's ratio
µ
negative ratio of the strain change Δε , in one of the two axes normal to the direction of extension,
n
to the corresponding strain change Δε in the direction of extension, within the linear portion of the
l
longitudinal versus normal strain curve
Note 1 to entry: It is expressed as a dimensionless ratio.
Note 2 to entry: Since the lateral strain change Δε is a negative number and the longitudinal strain change Δε is
n l
positive, the Poissons ratio as defined in ISO 527-1:2019, 3.10 is a positive number.
[SOURCE: ISO 527-1:2019, 3.10]
3.9
specimen coordinate axes
axes, where “1"-direction is normally defined in terms of a feature associated with the material
structure or the production process, such as the length direction in continuous-sheet processes (see
Figure 2) and the “2"-direction is perpendicular to the “1"-direction.
Note 1 to entry: The “1-direction is also referred to as the 0° or longitudinal direction and the “2’‘-direction as the
90° or transverse direction. The “3-direction” is perpendicular to the plane of the “1-direction” and “2-direction”.
The “3-direction” is also referred to as the “through-thickness” direction for planar systems.
Note 2 to entry: For unidirectional materials covered by part 5 of this International Standard, the direction
parallel to the fibres is defined as the “1"-direction and the direction perpendicular to the fibres (in the plane of
the prepreg/plate) as the “2"-direction.
4
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
Figure 2 — Fibre-reinforced plastic composite showing axes of symmetry
3.10
failure position
u
F
failure location of specimen type 4 within the local coordinate system (u, v) of the tapered section
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Figure 5.
4 Principle
According to ISO 527-1.
5 Apparatus
The apparatus shall conform to ISO 527-1:2019, Clause 5, except for the following:
The micrometre or its equivalent (see ISO 16012: 2015, 5.5) shall read to 0,01 mm or better. It shall
have a suitable-size ball-ended anvil if used on irregular surfaces and a flat anvil if used on flat, smooth
(e.g. machined) surfaces.
When using extensometers with specimen type 4, use a gauge length of 25 mm (see ISO 527-1:2019,
5.1.5).
It is recommended to check alignment of the specimen and loading train as described in Annex A.
6 Test specimens
6.1 Shape and dimensions
Four types of test specimen are specified for use with this document, as detailed and illustrated in
Figure 3 (type 1 B), Figure 4 (types 2 and 3) and Figure 5 (type 4).
Type 1B is for testing fibre-reinforced thermoplastics. Type 1B specimens may also be used for
fibre-reinforced thermosets if they break within the gauge length. Type 1B shall not be used for
multidirectional, continuous-fibre-reinforced materials.
Type 2 is rectangular without end-tabs, and Type 3 is rectangular with bonded end-tabs. They are
for testing fibre reinforced thermosets and thermoplastics. Specimens with unbonded end tabs are
considered as type 2.
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
The preferred width of type 2 and type 3 specimens is 25 mm, but widths of 50 mm or greater may be
used if the tensile strength is low due to the particular type of reinforcement used.
Type 4 is tapered without end-tabs and for testing fibre-reinforced composites, especially for testing
multidirectional, continuous-fibre reinforced thermoplastics. Please refer to Annex B.
The thickness of type 2, type 3 and type 4 specimens shall be between 2 mm and 10 mm.
To decide whether to use specimen with or without tabs, first carry out tests without using tabs
(specimen type 2 [rectangle] or type 4 [tapered]) and, if the tests are not successful, i.e. if almost all
specimens break in the grips (see Clause 7), perform test with bonded end tabs on the specimens
(specimen type 3). Refer to Annex C for guidance on unbonded tabs or gripping condition without tabs
using fine grip faces and careful control of the gripping force.
NOTE Continuous fibre reinforced composites typically have high fracture forces due to high tensile
strength of their fibres. Using specimen thicknesses larger than 4 mm can require an increased clamping length
to counter high clamping pressures.
The recommended specimen thickness for continuous-fibre-reinforced composites is 2 mm. For
compression-moulded materials, the thickness between the end-pieces of any type of specimen shall at
no point deviate from the mean by more than 2 %.
Symbol Name Dimensions in millimetres
a
l Overall length ≥150
3
l Length of narrow parallel-sided portion 60,0 ± 0,5
1
b
r Radius ≥60
b Width at ends 20,0 ± 0,2
2
b Width of narrow portion 10,0 ± 0,2
1
h Thickness 2 to 10
L Gauge length (recommended for extensometers) 50,0 ± 0,5
0
L Initial distance between grips 115 ± 1
a
For some materials, the length of the tabs can be extended (e.g. so that l = 200 mm) to prevent breakage or slippage of
3
the specimen in the jaws.
b
It should be noted that a thickness of 4 mm gives a specimen which is identical to the type 1B specimen specified in
ISO 527-2.
Figure 3 — Type 1B specimen
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SIST EN ISO 527-4:2022
ISO 527-4:2021(E)
a) Type 2 specimen
b) Type 3 specimen
Key
1 centrings holes (optional), ϕ D
2 jaws
Symbol Name Dimensions in millimetres
 Type 2 Type 3
L Overall length ≥250 ≥250
3
L Distance between end tabs — 150 ± 1
2
b Widt
...

SLOVENSKI STANDARD
oSIST prEN ISO 527-4:2020
01-september-2020
Polimerni materiali - Določevanje nateznih lastnosti - 4. del: Preskusni pogoji za
izotropne in ortotropne z vlakni ojačene polimerne kompozite (ISO/DIS 527-4:2020)
Plastics - Determination of tensile properties - Part 4: Test conditions for isotropic and
orthotropic fibre-reinforced plastic composites (ISO/DIS 527-4:2020)
Kunststoffe - Bestimmung der Zugeigenschaften - Teil 4: Prüfbedingungen für isotrop
und anisotrop faserverstärkte Kunststoffverbundwerkstoffe (ISO/DIS 527-4:2020)
Plastiques - Détermination des propriétés en traction - Partie 4 : Conditions d’essai pour
les composites plastiques renforcés de fibres isotropes et orthotropes (ISO/DIS 527-
4:2020)
Ta slovenski standard je istoveten z: prEN ISO 527-4
ICS:
83.120 Ojačani polimeri Reinforced plastics
oSIST prEN ISO 527-4:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 527-4:2020

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oSIST prEN ISO 527-4:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 527-4
ISO/TC 61/SC 13 Secretariat: JISC
Voting begins on: Voting terminates on:
2020-07-01 2020-09-23
Plastics — Determination of tensile properties —
Part 4:
Test conditions for isotropic and orthotropic fibre-
reinforced plastic composites
Plastiques — Détermination des propriétés en traction —
Partie 4: Conditions d'essai pour les composites plastiques renforcés de fibres isotropes et orthotropes
ICS: 83.120
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 527-4:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020

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oSIST prEN ISO 527-4:2020
ISO/DIS 527-4:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

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oSIST prEN ISO 527-4:2020
ISO/DIS 527-4:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 4
5 Apparatus . 4
6 Test specimens. 4
6.1 Shape and dimensions . 4
6.2 Preparation of specimens . 8
6.2.1 General. 8
6.2.2 End tabs (for type 3 specimens). 8
6.2.3 Applications of end tabs (for type 3 specimens) . 9
6.3 Gauge marks . 9
6.4 Checking the specimens . 9
6.5 Anisotropy . 9
7 Number of specimens . 9
8 Conditioning . 9
9 Procedure.10
9.1 Test atmosphere .10
9.2 Measurement of specimen dimensions .10
9.3 Clamping .10
9.4 Prestresses .10
9.5 Setting of extensometers and strain gauges and placing of gauge marks .10
9.6 Speed of testing .10
9.6.1 For type 1B test specimens .10
9.6.2 For type 2, type 3 and type 4 test specimens .10
9.7 Recording of data .11
10 Calculation and expression of results .11
10.1 Calculation of all properties for parallel sided specimens .11
10.2 Failure location related calculation of tensile strength for type 4 specimens.11
11 Precision .11
12 Test report .11
Annex A (normative) Specimen preparation (type 2 and type 3) .12
Annex B (informative) Alignment of specimens .14
Annex C (informative) Unbonded tabs or gripping condition without tabs using fine grip face .16
Annex D (informative) Testing with tapered tensile specimen geometry without tabs (type 4) .19
Annex E (normative) Failure location related calculation of tensile strength for type 4
specimens .22
Bibliography .25
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oSIST prEN ISO 527-4:2020
ISO/DIS 527-4:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13,
Composites and reinforcement fibres.
This second edition cancels and replaces the first edition (ISO 527-4: 1997), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Implementation of specimen type 4 (tapered tensile specimen) especially for testing of
multidirectional, continuous fibre-reinforced thermoplastic composites.
— Adjustment of gripping force or pressure (e.g. via torque or manometer depending on gripping
system used).
Implementation of Annex C (Informative) (Unbonded tabs or gripping condition without tabs using fine
grip faces), Annex D (Informative) (Testing with tapered tensile specimen geometry without tabs) and
Annex E (Normative)(Failure location related calculation of tensile strength for type 4 specimens)
A list of all parts in the ISO 527 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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Introduction
This document introduces a new test specimen, type 4, with a waisted geometry for use without
end tabs. The geometry has been developed to overcome difficulties with bonding end-tabbed test
specimens, especially when testing materials based on a thermoplastic matrix.
Guidance on gripping, including grip face design, is also added.
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oSIST prEN ISO 527-4:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 527-4:2020(E)
Plastics — Determination of tensile properties —
Part 4:
Test conditions for isotropic and orthotropic fibre-
reinforced plastic composites
1 Scope
1.1 This part of ISO 527 specifies the test conditions for the determination of the tensile properties of
isotropic and orthotropic fibre-reinforced plastic composites, based upon the general principles given
in part 1.
Unidirectionally reinforced materials are covered by Part 5.
1.2 The methods are used to investigate the tensile behaviour of the test specimens and for determining
the tensile strength, tensile modulus, Poisson's ratios and other aspects of the tensile stress/strain
relationship under the defined conditions.
1.3 The test method is suitable for use with the following materials:
— fibre-reinforced thermosetting and thermoplastic composites incorporating non-unidirectional
reinforcements such as mats, woven fabrics, woven rovings, chopped strands, combinations of such
reinforcements, hybrids, rovings, short or milled fibres or preimpregnated materials (prepregs)
(for directly injection-moulded specimens, see specimen 1A in ISO 527-2);
— combinations of the above with unidirectional reinforcements and multidirectional reinforced
materials constructed from unidirectional layers, provided such laminates are symmetrical (for
materials with completely, or mainly, unidirectional reinforcements, see ISO 527-5);
— finished products made from these materials.
The reinforcement fibres covered include glass fibres, carbon fibres, aramid fibres and other similar fibres.
1.4 The method is performed using specimens machined from a test panel made in accordance with
ISO 1268 or by equivalent methods, or from finished and semi-finished products with suitable flat areas.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions
of this part of ISO 527. At the time of publication, the editions indicated were valid. All standards are
subject to revision, and parties to agreements based on this part of ISO 527 are encouraged to investigate
the possibility of applying the most recent editions of the standards indicated below. Members of IEC
and ISO maintain registers of currently valid International Standards.
ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles
ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and
extrusion plastics
ISO 527-5, Plastics - Determination of tensile properties - Part 5: Test conditions for unidirectional fibre-
reinforced plastic composites
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ISO 1268, Plastics - Preparation of glass fibre reinforced, resin bonded, low-pressure laminated plates or
panels for test purposes
ISO 2818, Plastics — Preparation of test specimens by machining
ISO 3534-1, Statistics — Vocabulary and symbols — Part 1: General statistical terms and terms used in
probability
ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test
3 Terms and definitions
For the purposes of this part of ISO 527, the following definitions apply.
3.1
gauge length
See ISO 527-1, subclause 3.1.
3.2
thickness
h - See ISO 527-1, subclause 3.2
3.3
width
b - See ISO 527-1, subclause 3.3 for parallel sided specimens
b - See Annex D for tapered specimens
1
3.4
speed of testing
See ISO 527-1, subclause 3.5.
3.5
tensile stress
σ (engineering): See ISO 527-1, subclause 3.6, except that σ for “1"-direction specimens is defined as σ
1
and for "2"-direction specimens as σ (see 4.8 for definitions of these directions).
2
3.6
tensile strength
σ : See ISO 527-1, subclause 3.6.2, except that σ for "1"-direction specimens is defined as σ and for
M M M1
"2"-direction specimens as σ .
M2
3.7
tensile strain
ε: See ISO 527-1, subclause 3.7, except that ε for “1’‘-direction specimens is defined as ε and for
1
"2"-direction specimens as ε .
2
It is expressed as a dimensionless ratio or in percent.
3.7.1
tensile strain at tensile strength; tensile failure strain
ε : The tensile strain at the point corresponding to the tensile strength of the specimen.
M
For "1"-direction specimens, ε is defined as ε and for “2"-direction specimens as ε .
M M1 M2
It is expressed as a dimensionless ratio or in percent.
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3.8
modulus of elasticity in tension; Young’s modulus
E: See ISO 527-1, subclause 3.9, except that E for "1"-direction specimens is defined as E and for
1
“2"-direction specimens as E .
2
The strain values used are as given in ISO 527-1, subclause 3.9, i.e. ε ’ = 0,000 5 and ε” = 0,002 5 (see
figure 1), unless alternative values are given in the material or technical specifications.
3.9
Poisson’s ratio
μ: See ISO 527-1, subclause 3.10, except that for "1"-direction specimens μ is defined as μ and μ as μ ,
b 12 h 13
using the coordinates shown in figure 2. For "2"-direction specimens, μ is defined as μ and μ as μ .
b 21 h 23
3.10
specimen coordinate axes
The “1"-direction is normally defined in terms of a feature associated with the material structure or
the production process, such as the length direction in continuous-sheet processes (see figure 2). The
“2"-direction is perpendicular to the “1"-direction.
Note 1 to entry: The “1-direction is also referred to as the 0° or longitudinal direction and the “2’‘-direction as the
90° or transverse direction. The “3-direction” is perpendicular to the plane of the “1-direction” and “2-direction”.
The “3-direction” is also referred to as the “through-thickness” direction for planar systems.
Note 2 to entry: For unidirectional materials covered by part 5 of this International Standard, the direction
parallel to the fibres is defined as the “1"-direction and the direction perpendicular to the fibres (in the plane of
the prepreg/plate) as the “2"-direction.
Key
X strain,
Y stress, σ
a Slope E
Figure 1 — Stress-strain curve
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3.11
failure position
u : The failure location of the specimen type 4 within the local coordinate system (u, v) of the tapered
F
section.
Figure 2 — Fibre-reinforced plastic composite showing axes of symmetry
4 Principle
See ISO 527-1, clause 4.
5 Apparatus
See ISO 527-1, clause 5, except for the following:
The micrometre or its equivalent (see ISO 16012, subclause 5.2) shall read to 0,01 mm or better. It shall
have a suitable-size ball-ended anvil if used on irregular surfaces and a flat anvil if used on flat, smooth
(e.g. machined) surfaces.
When using extensometers with specimen type 4, a gauge length of 25 mm (see ISO 527-1, subclause
5.1.5) is recommended.
NOTE It is recommended that alignment of the specimen and loading train be checked as described in Annex B.
6 Test specimens
6.1 Shape and dimensions
Four types of test specimen are specified for use with this part of ISO 527, as detailed and illustrated in
figure 3 (type 1 B) and figure 4 (types 2 and 3) and figure 5 (type 4).
Type 1B is for testing fibre-reinforced thermoplastics. Type 1B specimens may also be used for
fibre-reinforced thermosets if they break within the gauge length. Type 1B shall not be used for
multidirectional, continuous-fibre-reinforced materials.
Type 2 (rectangular without end-tabs) and type 3 (rectangular with bonded end-tabs) are for testing fibre-
reinforced thermosets and thermoplastics. Specimens with unbonded end tabs are considered as type 2.
The preferred width of type 2 and type 3 specimens is 25 mm, but widths of 50 mm or greater may be
used if the tensile strength is low due to the particular type of reinforcement used.
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Type 4 (tapered without end-tabs) is for testing fibre-reinforced composites, especially for testing
multidirectional, continuous-fibre reinforced thermoplastics. Please refer Annex D (Testing with
tapered tensile specimen geometry without end-tabs).
The thickness of type 2, type 3 and type 4 specimens shall be between 2 mm and 10 mm.
To decide whether to use specimen with or without tabs, first carry out tests without using tabs
(specimen type 2 [rectangle] or type 4 [tapered]) and, if the tests are not unsuccessful, i.e. if almost
all specimens break in the grips (see ISO 527-4, clause 7), perform test with bonded end tabs on the
specimens (specimen type 3). Refer to Annex C for guidance on “Unbonded tabs or gripping condition
without tabs using fine grip faces”.
NOTE Continuous fibre reinforced composites typically have high fracture forces due to high tensile
strength of their fibres. Using specimen thicknesses larger than 4 mm can require an increased clamping length
to counter high clamping pressures.
The recommended specimen thickness for continuous-fibre-reinforced composites is 2 mm. For
compression-moulded materials, the thickness between the end-pieces of any type of specimen shall at
no point deviate from the mean by more than 2 %.
Specimen type Dimensions in millimetres
a
l Overall length ≥150
3
l Length of narrow parallel-sided portion 60,0 ± 0,5
1
b
r Radius ≥60
b Width at ends 20,0 ± 0,2
2
b Width of narrow portion 10,0 ± 0,2
1
h Thickness 2 to 10
L Gauge length (recommended for extensometers) 50,0 ± 0,5
0
L Initial distance between grips 115 ± 1
a
For some materials, the length of the tabs may need to be extended (e.g. so that l = 200 mm) to prevent breakage or
3
slippage of the specimen in the jaws.
b
It should be noted that a thickness of 4 mm gives a specimen which is identical to the type 1B specimen specified in
ISO 527-2 and ISO 3167:1993, Plastics - Multipurpose test specimens.
Figure 3 — Type 1B specimen
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a) Type 2 specimen
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b) Type 3 specimen

 Dimensions in millimetres
 Type 2 Type 3
L Overall length ≥ 250 ≥ 250
3
L Distance between end tabs - 150 ± 1
2
b Width 25 ± 0,5 or 50 ± 0,5 25 ± 0,5 or 50 ± 0,5
1
h Thickness 2 to 10 2 to 10
L Gauge length (recommended for extensometers) 50 ± 1 50 ± 1
0
L Initial distance between grips (nominal) 150 ± 1 150 ± 1
L Length of end tabs - ≥ 50
T
h Thickness of end tabs - 1 to 3
T
D Diameter of centring holes 3 ± 0,25 3 ± 0,25
NOTE Requirements on specimen quality and parallelism are given in ISO 527-1, clause 6.4.
Figure 4 — Type 2 and type 3 specimens
Figure 5 — Type 4 specimen
Equations (1) and (2) are the Bezier curve specifically resolved for the specimen type 4 to calculate a
polyline being applicable on most CNC machines. They define the local coordinates (u, v) of the tapered
section’s edge depicted in figure 5. The transformation into the specimens coordinate system (x, y) is
depicted in figure 8. The variable t should not exceed increments higher than 0.025 to avoid a course
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partitioned polyline. A more detailed description on how to construct the type 4 specimen is given in
Annex D2.
32
ut()=+63.08tt9841+ 45. 8t (1)
3
vt =15. t (2)
()
with∈[]01,.withΔ≤t 0025
 Dimensions in millime-
tres
 Type 4
L Total length ≥ 300
3
b Width of parallel mid-section 25 ± 0,5
1
b Width at ends 28 ± 0,5
2
h Thickness 2 to 10
L Gauge length (recommended for extensometers) 25 ± 1
0
L Initial distance in between grips (nominal) 200
P0 Bézier curve control point in (u, v) coordinates (0, 0)
P1 Bézier curve control point in (u, v) coordinates (4.86, 0)
P2 Bézier curve control point in (u, v) coordinates (13.0, 0)
P3 Bézier curve control point in (u, v) coordinates (87.0, 1.5)
NOTE Requirements on specimen quality and parallelism are given in ISO 527-1, clause 6.4.
6.2 Preparation of specimens
6.2.1 General
In the case of moulding and lamination materials, prepare a panel in accordance with ISO 1268 or
another specified/agreed procedure. Cut individual specimens, or groups of specimens in the case of
type 3 specimens (see Annex A), from the panel.
In the case of finished products (for example, for quality control during manufacture or on delivery),
take specimens from flat areas.
Parameters for machining specimens are specified in ISO 2818. Further guidance on cutting specimens
is given in Annex A.
For machining of type 4 specimens only, a polyline of the required profile can be calculated using the
equations given in Annex D.
6.2.2 End tabs (for type 3 specimens)
The ends of the specimen shall be reinforced, preferably with end tabs made of cross-ply or fabric glass-
fibre/resin laminate with the fibres at ± 45° to the specimen axis. The tab thickness shall be between 1
mm and 3 mm, with a tab angle of 90° (i.e. not tapered).
Alternative tabbing arrangements are permissible, but shall be shown, before use, to give at least equal
strength and no greater coefficient of variation (see ISO 527-1, subclause 10.5 and ISO 3534-l) than the
recommended tabs. Possible alternatives include tabs made from the material under test, mechanically
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fastened tabs, unbonded tabs made of rough materials (such as emery paper or sandpaper), and fine
grip faces without tabs as described in Annex C.
6.2.3 Applications of end tabs (for type 3 specimens)
Bond the end tabs to the specimen with a high-stretch adhesive as described in Annex A.
NOTE The same procedure can be used for individual specimens and for a group of specimens.
6.3 Gauge marks
See ISO 527-1, subclause 6.3.
When using specimen type 4 it is advisable to mark the parallel mid-section of the specimen. The first
mark indicates the centre of the parallel mid-section. Two additional marks should be placed with a
distance of 12,5 mm from the centre on both sides (see Figure 6). The marks indicate the width and
thickness measurement points of the specimen. In addition, the outer marks indicate the mechanical
extensometer placement positions if used.
Figure 6 — Positions of supporting marks
6.4 Checking the specimens
See ISO 527-1, subclause 6.4.
6.5 Anisotropy
The properties of fibre-reinforced plastic composites frequently vary with direction in the plane of the
sheet (anisotropy). For this reason, it is recommended that two groups of test specimens be prepared
with their major axes parallel and perpendicular, respectively, to the direction of some feature which
is inferred from a knowledge of the structure of the material or its method of manufac
...