EN ISO 179-2:2020

SLOVENSKI STANDARD
01-september-2020
Nadomešča:
SIST EN ISO 179-2:2000
SIST EN ISO 179-2:2000/A1:2014
Polimerni materiali - Določanje udarne žilavosti po Charpyju - 2. del: Preskus
udarne žilavosti z instrumentalnim prikazom (ISO 179-2:2020)
Plastics - Determination of Charpy impact properties - Part 2: Instrumented impact test
(ISO 179-2:2020)
Kunststoffe - Bestimmung der Charpy-Schlageigenschaften - Teil 2: Instrumentierte
Schlagzähigkeitsprüfung (ISO 179-2:2020)
Plastiques - Détermination des caractéristiques au choc Charpy - Partie 2: Essai de choc
instrumenté (ISO 179-2:2020)
Ta slovenski standard je istoveten z: EN ISO 179-2:2020
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 179-2
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2020
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 179-2:1999
English Version
Plastics - Determination of Charpy impact properties - Part
2: Instrumented impact test (ISO 179-2:2020)
Plastiques - Détermination des caractéristiques au choc Kunststoffe - Bestimmung der Charpy-
Charpy - Partie 2: Essai de choc instrumenté (ISO 179- Schlageigenschaften - Teil 2: Instrumentierte
2:2020) Schlagzähigkeitsprüfung (ISO 179-2:2020)
This European Standard was approved by CEN on 10 May 2020.

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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 179-2:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 179-2:2020) 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 December 2020, and conflicting national standards
shall be withdrawn at the latest by December 2020.
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 179-2:1999.
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 179-2:2020 has been approved by CEN as EN ISO 179-2:2020 without any modification.

INTERNATIONAL ISO
STANDARD 179-2
Second edition
2020-05
Plastics — Determination of Charpy
impact properties —
Part 2:
Instrumented impact test
Plastiques — Détermination des caractéristiques au choc Charpy —
Partie 2: Essai de choc instrumenté
Reference number
ISO 179-2:2020(E)
©
ISO 2020
ISO 179-2:2020(E)
© 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
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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

ISO 179-2:2020(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Principle . 7
5 Apparatus . 7
6 Test specimens.11
7 Procedure.11
8 Calculation and expression of results .12
8.1 General .12
8.2 Calculation of deflection .12
8.3 Calculation of energy .13
8.4 Calculation of impact strength .14
8.4.1 Unnotched test specimens.14
8.4.2 Notched test specimens .14
8.5 Statistical parameters .15
8.6 Number of significant figures .15
9 Precision .15
10 Test report .15
Annex A (informative) Inertial peak .17
Annex B (informative) Mass of frame .20
Annex C (informative) Precision data .21
Bibliography .23
ISO 179-2:2020(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 on 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 the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2,
Mechanical properties, 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 179-2:1997), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 179-2:1997/Cor 1:1998 and the Amendment
ISO 179-2:1997/Amd 1:2011.
The main changes compared to the previous edition are as follows:
— references to ISO 13802:2015 have been updated;
— force calibration requirements have been clarified;
— a new subclause for the determination of test speed when using falling mass instruments has been
added (see 5.1.6).
A list of all parts of the ISO 179 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.
iv © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 179-2:2020(E)
Plastics — Determination of Charpy impact properties —
Part 2:
Instrumented impact test
1 Scope
1.1 This document specifies a method for determining Charpy impact properties of plastics from
force-deflection diagrams. Different types of rod-shaped test specimens and test configurations, as well
as test parameters depending on the type of material, the type of test specimen and the type of notch, are
defined in ISO 179-1.
Dynamic effects such as load-cell/striker resonance, test specimen resonance and initial-contact/
inertia peaks are described in this document (see Figure 1, Curve b, and Annex A).
1.2 ISO 179-1 is suitable for characterizing the impact behaviour by the impact strength only and for
using apparatus whose potential energy is matched approximately to the particular energy to break
to be measured (see ISO 13802:2015, Annex E). This document is used to record a force-deflection or
force-time diagram for detailed characterization of the impact behaviour, and for developing automatic
apparatus, i.e. avoiding the need to match energy.
The method described in this document is also suitable for:
— acquiring more and different materials characteristics under impact conditions;
— supervising the Charpy test procedure, as this instrumentation allows detection of typical
operational mistakes, such as the specimen not being in close contact with the supports;
— automatically detecting the type of break;
— pendulum type instruments to avoid frequent changes of pendulum hammers;
— measuring fracture mechanical properties described in other ISO standards.
1.3 For the range of materials which can be tested by this method, see ISO 179-1:2010, Clause 1.
1.4 For the general comparability of test results, see ISO 179-1:2010, Clause 1.
1.5 Information on the typical behaviour of materials can be obtained by testing at different
temperatures, by varying the notch radius and/or specimen thickness and by testing specimens prepared
under different conditions.
It is not the purpose of this document to give an interpretation of the mechanism occurring at every
point on the force-deflection diagram. These interpretations are a task for on-going scientific research.
1.6 The test results obtained with this method are comparable only if the conditions of test specimen
preparation, as well as the test conditions, are the same. The impact behaviour of finished products
cannot, therefore, be predicted directly from this test.
ISO 179-2:2020(E)
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 179-1:2010, Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented
impact test
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO 2602, Statistical interpretation of test results — Estimation of the mean — Confidence interval
ISO 16012, Plastics — Determination of linear dimensions of test specimens
ISO 13802:2015, Plastics — Verification of pendulum impact-testing machines — Charpy, Izod and tensile
impact-testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 179-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
impact velocity
v
I
velocity of the striker relative to the test specimen supports at the moment of impact
Note 1 to entry: It is expressed in metres per second (m/s).
3.2
inertial peak
first peak in a force-time or force-deflection diagram
Note 1 to entry: Inertial peak arises from the inertia of that part of the test specimen accelerated after the first
contact with the striker (see Figure 1, Curve b, and Annex A).
3.3
impact force
F
force exerted by the striking edge on the test specimen in the direction of impact
Note 1 to entry: It is expressed in newtons (N).
2 © ISO 2020 – All rights reserved

ISO 179-2:2020(E)
a) Force-deflection (N and C,t)
b) Force-time (C,b)
Key
X1 deflection (s) after impact in millimetres t time at break
B
X2 time after impact in milliseconds, ms s deflection at break
B
Y force (F) in newtons, N N no break, specimen pulled through
F maximum impact force C,t complete break, tough
M
F peak force of inertial peak C,b complete break, brittle
I
s deflection at maximum impact force F 1 5% of the maximum impact force
M M
s limiting deflection, beginning off pull-through
L
NOTE For the types of failure, see Figure 2.
Figure 1 — Typical force-deflection and force-time curves
ISO 179-2:2020(E)
3.4
deflection
s
displacement of the striker relative to the test specimen supports after impact, starting at first contact
between striker and test specimen
Note 1 to entry: It is expressed in millimetres (mm).
3.5
impact energy
W
energy expended in accelerating, deforming and breaking the test specimen during the deflection (3.4)
Note 1 to entry: It is expressed in joules (J).
3.6
maximum impact force
F
M
maximum value of the impact force (3.3) in a force-time or force-deflection diagram
Note 1 to entry: See Figure 1.
Note 2 to entry: It is expressed in newtons (N).
3.7
deflection at maximum impact force
s
M
deflection (3.4) at which the maximum impact force (3.6) occurs
Note 1 to entry: See Figure 1.
Note 2 to entry: It is expressed in millimetres (mm).
3.8
energy to maximum impact force
W
M
energy expended up to the deflection at maximum impact force (3.7)
Note 1 to entry: It is expressed in joules (J).
3.9
deflection at break
s
B
deflection (3.4) at which the impact force is reduced to less than or equal to 5 % of the maximum impact
force (3.6)
Note 1 to entry: See Figure 1.
Note 2 to entry: It is expressed in millimetres (mm).
3.10
impact energy at break
W
B
impact energy (3.5) up to the deflection at break (3.9)
Note 1 to entry: It is expressed in joules (J).
4 © ISO 2020 – All rights reserved

ISO 179-2:2020(E)
3.11
Charpy impact strength
Charpy notched impact strength
a (a )
cU cN
impact energy at break (3.10) relative to the initial central cross-sectional area A (A ) of the unnotched
N
(notched) specimen
Note 1 to entry: It is expressed in kilojoules per square metre (kJ/m ).
Note 2 to entry: See 8.4 and ISO 179-1:2010, 3.1 and 3.2.
3.12
type of failure
type of deformation behaviour of the material under test up to and including the breaking event
Note 1 to entry: Failure types are: complete break (3.13), hinge break (3.14), partial break (3.15), non-break (3.16).
See Figure 2.
Note 2 to entry: Types t, b and s represent subgroups of the complete break C and hinge break H defined below. For
these types, values of the impact energy at break W , and thus for the Charpy impact strength, may be averaged
B
to give a common mean value. For specimens giving a partial break P and for materials exhibiting interlaminar
shear fracture, see ISO 179-1:2010, 7.7. For specimens showing more than one failure type, see ISO 179-1:2010, 7.7
and ISO 179-1:2010, Clause 10 l).
Note 3 to entry: As can be seen from Figure 2, the deflection and the impact energy at maximum force are
identical to the deflection and impact energy at break in the case of splintering failure (see Curve s) and brittle
failure (see Curve b), where unstable cracking takes place at the maximum impact force.
Note 4 to entry: Usually, complete and hinge breaks cannot be differentiated in an automatic assessment based
on the force-time or force deflection-curve.
ISO 179-2:2020(E)
Key
N no break (3.16) s deflection limit; beginning of pull-through
L
P partial break (3.15) x deflection s after impact in millimetres
C complete break (3.13) y impact force in newtons, N
NOTE 1  Due to the different modes of deformation, force-deformation curves obtained using this document
[1]
show features which are different from those obtained using ISO 6603-2 . In particular, the first damage event
in instrumented puncture tests frequently appears as a slight sudden force decrease (crack initiation), followed
by a gradual force increase. Force increases after crack initiation are never observed in instrumented three-point-
bending impact tests. Furthermore, inertial effects are not as pronounced in plate impact tests as they are in bending
impacts tests (see Annex A).
NOTE 2  The distinction between break types P and C,t is difficult. As there is some extent of unstable crack growth
in the F-s-diagram labelled C,t, the breaking behaviour was rated as less ductile than in case P when drafting the
document. Therefore, the letter “t” was used instead of “d”, which could be associated with ductile behaviour and
would better apply to break types N and P.
NOTE 3  This document can be applied to automatic testing routines. For this it is also necessary to automatically
assign the types of break by a suitable assessment of the force-time or force deflection traces observed. The table
below is an example of assessment rules that have been used successfully. Both rules are to be met for assignment.
Type of break Rule for deflection Rule for force
F(s ) c*F
L M
s ≥ s
B L
Non break
The factor c was determined experimentally
s = 31mm
L
and set to c = 0,3
F ≤ F(s ) ≤ c*F
0 L M
Partial break s ≥ s
B L F is the level of force at which the test is con-
sidered to be finished, e.g. F = 0,05*F
0 M
Type s:  (s – s ) ≤ 1mm
B M
Type b:  (s – s ) ≤ 2mm
B D
Type t:  (s – s ) ≥ 2mm
B D
Complete break
s is the deflection after s ,
D M
where the steepest decline
of the F-s-curve occurs
Figure 2 — Typical force-deflection curves showing different failure modes for Type 1
specimens tested edgewise
3.13
complete break
C
break where the specimen separates into two or more pieces, subdivided in the following behaviours:
Note 1 to entry: See Figure 2.
3.13.1
tough break
t
yielding followed by stable cracking, resulting in a force at the deflection limit s which is less than or
L
equal to 5 % of the maximum force
3.13.2
brittle break
b
yielding followed by unstable cracking
6 © ISO 2020 – All rights reserved

ISO 179-2:2020(E)
3.13.3
splintering break
s
unstable cracking followed by splintering
3.14
hinge break
H
incomplete break, such that one part of the specimen cannot support itself above the horizontal when
the other part is held vertically (less than 90° included angle)
3.15
partial break
P
incomplete break that does not meet the definition for a hinge or complete break
Note 1 to entry: For automatic detection resulting in a force at the deflection limit s which is greater than 5 % of
L
the maximum force.
3.16
non-break
N
yielding followed by plastic deformation up to the deflection limit, s
L
Note 1 to entry: The test specimen shows extended plastic deformation but no visible fracture surfaces.
4 Principle
A rod-shaped test specimen, supported near its ends as a horizontal beam, is impacted perpendicularly,
with the line of impact midway between the supports, and bent at a high, nominally constant velocity.
During the impact, the impact force is recorded as a function of time and/or deflection. Depending on
the method of evaluation, the deflection of the specimen may be either measured directly by suitable
measuring devices or, in the case of energy carriers which give a frictionless impact, calculated from
the initial velocity and the force as a function of time. The force-deflection diagram obtained in these
tests describes the high-bending-rate impact behaviour of the specimen from which several aspects of
the material properties may be inferred.
5 Apparatus
5.1 Test machine
5.1.1 Basic components
The basic components of the test machine are the energy carrier, the striker and the frame with its
specimen supports. The energy carrier may be of the inertial type (e.g. a pendulum or free-falling dart,
which may be spring- or pneumatically assisted before impact) or of the hydraulic type.
The test machine shall ensure that the specimen is bent by the impact at a nominally constant velocity
perpendicular to the specimen length. The force exerted on the specimen shall be measurable, and its
deflection in the direction of impact shall be derivable or measurable.
If the test machine is of the pendulum type it shall be verified according to ISO 13802:2015, Clause 6
and Annex A, as applicable.
5.1.2 Energy carrier
For the low-energy pendulum types specified in ISO 179-1 (see also ISO 13802:2015, Annex A), the
impact velocity, v , is (2,90 ± 0,15) m/s and for the high-energy types it is (3,8 ± 0,2) m/s. For the purposes
I
ISO 179-2:2020(E)
of comparing impact strength data obtained using this method with data obtained in accordance with
ISO 179-1, the impact velocity used in this document shall be (2,90 ± 0,15) m/s, although it may be
desirable to also use the impact velocity v = (3,8 ± 0,2) m/s.
I
NOTE 1 The height of the inertial peak F (see Figure 1, Curve b), and also the amplitudes of the subsequent
I
vibrations of the specimen, increase with increasing impact velocity. For basic information about these vibrations,
see Annex A and References [1] and [3]. For further information about the interpretation of the inertial peak and
the damping of vibrations, see Annex A.
NOTE 2 For special applications, e.g. testing precracked test specimens to obtain data on fracture properties,
it is useful to use a lower impact velocity of, for example, 1 m/s ± 0,05 m/s to reduce the vibrations mentioned
in NOTE 1.
To avoid obtaining results which cannot be compared due to the viscoelastic behaviour of the material
under test, the decrease of velocity during impact shall not exceed 10 % if the energy carrier is rated to
less than 50 J at the speed being selected for testing. These mass carriers allow measurements between
0 % and 20 % of their nominal work capacity, E.
For the sake of extending the application range of pendulum impact instruments, in case of energy
carriers larger or equal to 50 J at the speed selected for testing, a range of 0 % to 80 % of its nominal
work capacity is permitted, this leading to a decrease of speed of 55 % in extreme cases.
The hydraulic-type energy carrier is a high-speed impact-testing machine with suitable attachments.
In the case of gravitationally accelerated energy carriers, the above impact velocities correspond to
drop heights of (43 ± 5) cm and (74 ± 7) c
...