EN 16613:2019

SLOVENSKI STANDARD
01-april-2020
Steklo v gradbeništvu - Lepljeno steklo in lepljeno varnostno steklo - Določevanje
mehanskih lastnosti vmesnih slojev
Glass in building - Laminated glass and laminated safety glass - Determination of
interlayer viscoelastic properties
Glas im Bauwesen - Verbundglas und Verbundsicherheitsglas - Bestimmung der
mechanischen Eigenschaften von Zwischenschichten
Verre dans la construction - Verre feuilleté et verre feuilleté de sécurité - Détermination
des propriétés mécaniques d’un intercalaire
Ta slovenski standard je istoveten z: EN 16613:2019
ICS:
81.040.20 Steklo v gradbeništvu Glass in building
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16613
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 81.040.20
English Version
Glass in building - Laminated glass and laminated safety
glass - Determination of interlayer viscoelastic properties
Verre dans la construction - Verre feuilleté et verre Glas im Bauwesen - Verbundglas und
feuilleté de sécurité - Détermination des propriétés Verbundsicherheitsglas - Bestimmung der
mécaniques d'un intercalaire mechanischen Eigenschaften von Zwischenschichten
This European Standard was approved by CEN on 21 July 2019.

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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16613:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 6
5 Selection of testing procedure . 7
5.1 Isotropic interlayer materials . 7
5.2 Non-isotropic interlayer materials . 7
5.3 Interlayers which cannot be formed into small test pieces . 8
6 Test procedure . 8
6.1 General . 8
6.2 Test specimens . 8
6.3 Test method . 8
6.4 Determination of E (T ,f) . 9
L ref
7 Evaluation of ω . 10
7.1 Determining E (Τ,f) . 10
L
7.2 Load durations and temperature ranges. 11
7.3 Determining the interlayer stiffness family . 11
8 Test report . 14
Annex A (normative) Alternative method for non-isotropic interlayers and interlayers
which cannot be formed into small test pieces . 15
Annex B (normative) Preparation of test specimens . 17
Annex C (normative) Interlayer stiffness family. 18
Annex D (normative) Determination of the interlayer shear transfer coefficient from the
interlayer modulus . 19
Bibliography . 22

European foreword
This document (EN 16613:2019) has been prepared by Technical Committee CEN/TC 129 “Glass in
building”, 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 April 2020 and conflicting national standards shall be
withdrawn at the latest by April 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.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
Introduction
The purpose of this document is to provide the viscoelastic properties of interlayer materials in order
that calculations for the load resistance of laminated glass panes can be undertaken.
In addition, this document includes a procedure for categorizing the interlayer materials into families,
which can be associated with shear transfer coefficients which are used in a simplified calculation
method according to EN 16612.
1 Scope
This document specifies a test method for determining the mechanical viscoelastic properties of
interlayer materials. The interlayers under examination are those used in the production of laminated
glass and/or laminated safety glass. The interlayer viscoelastic properties are needed in order to
determine the load resistance of laminated glass.
From the tensile modulus in particular conditions of temperature and load duration, an interlayer can
be placed into a family that relates to a specific interlayer shear transfer coefficient, ω. This value can be
used in the simplified calculation method described in EN 16612.
Informative Annex D explains the background to the determination of families relating to a specific
interlayer shear transfer coefficient.
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.
EN 1288-3, Glass in building - Determination of the bending strength of glass - Part 3: Test with specimen
supported at two points (four point bending)
EN 16612, Glass in building – Determination of the lateral load resistance of glass panes by calculation
EN ISO 6721-1, Plastics — Determination of dynamic mechanical properties — Part 1: General principles
(ISO 6721-1)
ISO 6721-4, Plastics — Determination of dynamic mechanical properties — Part 4: Tensile vibration —
Non-resonance method
ISO 6721-11, Plastics — Determination of dynamic mechanical properties — Part 11: Glass transition
temperature
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
glass transition temperature
interval of temperature in which a material changes from a rubbery state to a glassy solid state
3.2
interlayer shear transfer coefficient
coefficient between 0 and 1 describing the ability of an interlayer material to transfer shear forces
between the glass plies of a laminated glass plate when submitted to bending
3.3
stiffness family
group of interlayers having similar properties for the temperature range and load durations considered
3.4
vitreous polymer
polymer presenting a glass transition temperature in the range of building applications
4 Symbols and abbreviations
b Width of the test specimen
C , C Parameters in the Williams–Landel–Ferry (WLF) viscoelastic formula
1 2
e Thickness of the test specimen
E Young’s Modulus of glass
G
E
Young’s Modulus of the interlayer material
L
f Frequency
F Four point bend test load
G Shear modulus of the interlayer material
L
h Nominal thickness of ply k of a laminated glass
k
h Distance of the mid-plane of the glass ply k from the mid-plane of the laminated glass
m;k
h Equivalent thickness of monolithic glass for a laminated glass deflecting under load
mono
H Height of the test specimen
L Distance between centre lines of the bending rollers
B
L Distance between centre lines of the supporting rollers
S
Q Self-weight area density of four point bend test specimen
t Load duration
T Temperature
T Glass transition temperature
g
T
Reference temperature
ref
w Measured deflection of four point bend test specimen
α(Τ) Temperature transformation parameter in the WLF viscoelastic formula (known as the
'shift factor')
μ Poisson’s number of the interlayer material
ω Interlayer shear transfer coefficient
5 Selection of testing procedure
5.1 Isotropic interlayer materials
A practical method for testing isotropic interlayer materials is to undertake a tensile test which can be
used to determine the shear modulus using the following relationship:
E
L
(1)
G =
L
2()1 + µ
where
μ is the Poisson’s number of the interlayer (μ can be taken as 0,49 for an isotropic interlayer).
This leads to the approximation.
E ≈ 3G (2)
LL
A typical test piece for testing isotropic interlayers according to ISO 6721-4 is shown in Figure 1.

Figure 1 — Dimensions of the isotropic interlayer test piece used for tensile test
Typical dimensions of the test piece are:
▪ H = 10 mm
▪ b = 5 mm
▪ e approximately 2,3 mm (equivalent to stacking 6 plies of interlayer each with nominal thickness of
0,38 mm).
5.2 Non-isotropic interlayer materials
In the case of interlayers which are not isotropic materials (an example is the acoustic tri-layer PVB),
these cannot be assessed by the method shown in 5.1.
For these interlayer materials, the relevant interlayer properties can be determined by calculation from
the results of bending tests. A method for doing this is given in Annex A.
5.3 Interlayers which cannot be formed into small test pieces
There are some interlayers which cannot be formed into test pieces like those described in 5.1 or which
are not stable with exposed edges in such small sizes.
For these interlayer materials, the relevant interlayer properties can be determined by calculation from
the results of bending tests. A method for doing this is given in Annex A.
6 Test procedure
6.1 General
The method uses the tests described in ISO 6721-1, ISO 6721-4, and ISO 6721-11. ISO 6721-1 gives an
overview of the principles of these tests.
It shall be ensured that the testing regime (temperature, frequency) is within the linear-viscoelastic
region of behaviour, by undertaking amplitude sweeps.
6.2 Test specimens
The test specimens shall be manufactured from samples representative of normal interlayer material
production. The test specimens shall be processed under normal laminating conditions (see Annex B).
For the purposes of the test, the thickness, e, of the test specimens should be not less than 2,2 mm thick
and not more than 4,0 mm thick. The layering and stacking of the interlayer material to achieve an
appropriate thickness shall be representative of normal production processes.
The test specimen size and tolerances on dimensions shall be determined according to the
requirements of ISO 6721-4.
Two sets of test specimens are required. One set is used for determining the glass transition
temperature, T , (see 6.3.1). The other set is used for the evaluation of the E (T ,f) curve (see 6.3.2,
g L ref
6.4).
6.3 Test method
6.3.1 Glass transition temperature, T
g
Initial tests shall be conducted on at least three test specimens according to ISO 6721-11 to determine
the glass transition temperature of the interlayer material. This is used to refine the temperatures
assessed in 6.3.2.
NOTE If the interlayer material is not a vitreous polymer, it may not be possible to determine a glass
transition temperature.
6.3.2 Determination of E (Τ, f)
L
A series of tests shall be conducted according to ISO 6721-4 to evaluate E (Τ,f) for a range of
L
frequencies, f, and a range of temperatures, Τ, sufficient to define the interlayer modulus, E .
L
The test temperatures shall be selected as follows.
(a) If a glass transition temperature has been determined:
• One test temperature is the glass transition temperature, T , determined in 6.3.1
g
• One test temperature is (T –3) °C;
g
• One test temperature is (T +3) °C;
g
• One test temperature is 20 °C;
• Other test temperatures shall be selected to give coverage of the temperature range, −20 °C to
+60 °C;
• A minimum of 15 different test temperatures shall be used.
(b) If a glass transition temperature has not been determined:
• One test temperature is 20 °C;
• One test temperature is 17 °C;
• One test temperature is 23 °C;
• Other test temperatures shall be selected to give coverage of the temperature range, −20 °C to
+60 °C;
• A minimum of 15 different test temperatures shall be used.
The frequencies to be tested at each temperature should cover the range 0,1 Hz to at least 100 Hz,
testing at least 24 frequencies evenly spread through the range.
6.4 Determination of E (T ,f)
L ref
The results obtained from 6.3.2 are used to determine a master curve for E (T ,f) for the interlayer at
L ref
the reference temperature, T , at any frequency (see Fig
...