Railway Applications - Acoustics - Determination of the dynamic stiffness of elastic track components related to noise and vibration - Rail pads and rail fastening assemblies

This European Standard specifies laboratory test procedures to determine the dynamic stiffness of resilient components of track for the purpose of evaluating the environmental noise and vibration performance of the track.
This standard is applicable to complete track fastening assemblies and to pad components of fastening systems.
It is applicable to specimens of a single rail seat fastener.
It is applicable to the measurement of a tangent, dynamic stiffness under a prescribed pre-load and the associated hysteretic damping loss factor.
It provides measurement methods and pre-load, excitation and frequency range conditions for application to ground borne and structure borne noise as well as for rolling noise.
It provides measurement methods and pre-load, excitation and frequency range conditions for application to ground borne and structure borne noise as well as for rolling noise.
It is not applicable to the measurement of the stiffness of pads and fastening assemblies under static or low frequency dynamic loading which is specified in EN 13146-9.

Bahnanwendungen - Akustik - Bestimmung der dynamischen Steifigkeit von elastischen Komponenten im Oberbau in Bezug auf Schall und Schwingungen - Zwischenlagen und Schienenbefestigungssysteme

Dieses Dokument legt Labor-Prüfverfahren zur Bestimmung einer hochfrequenten dynamischen Steifigkeit, der „akustischen Steifigkeit“, von elastischen Komponenten von Schienenbefestigungssystemen fest.
Dieses Dokument ist anwendbar auf komplette Schienenbefestigungssysteme und auf Zwischenlagen/Zwischenplatten von Befestigungssystemen, einschließlich sowohl diskreter als auch kontinuierlicher Befestigungs¬systeme.
Es ist anwendbar auf die Messung der dynamischen Transfersteifigkeit unter einer vorgeschriebenen Vorlast und dem damit verbundenen hysteretischen Dämpfungsverlustfaktor.
Es stellt Messverfahren und Vorlast-, Anregungs- und Frequenzbereichsbedingungen für die Anwendung bei Boden- und Körperschall sowie bei Rollgeräuschen zur Verfügung.
Es ist nicht anwendbar auf die Messung der Steifigkeit von Zwischenlagen/Zwischenplatten und Befestigungssystemen unter statischer oder niederfrequenter dynamischer Belastung, die für die Oberbaumechanik verwendet wird.

Applications ferroviaires - Acoustique - Détermination de la raideur dynamique des composants élastiques de la voie pour le bruit et les vibrations - Semelles sous rail et systèmes de fixation du rail

Le présent document spécifie les modes opératoires d'essai en laboratoire pour déterminer la raideur dynamique à haute fréquence (la « raideur acoustique ») des composants élastiques  provenant des systèmes de fixation du rail.
Le présent document est applicable aux systèmes de fixation du rail complets ainsi qu'aux composants « semelles » des systèmes de fixation, notamment les systèmes de fixation continus et discrets (ponctuels).
Il est applicable à la mesure de la raideur dynamique de transfert sous une précharge prescrite et du facteur de perte de l'amortissement hystérétique associé.
Il fournit les méthodes de mesure et les conditions de précharge, d'excitation et de plage de fréquences à appliquer pour évaluer le bruit solidien et le bruit propagé par le sol, ainsi que le bruit de roulement.
Il n'est pas applicable à la mesure de la raideur des semelles et des systèmes de fixation sous une charge statique ou dynamique basse fréquence utilisée pour évaluer les performances mécaniques de la voie.

Železniške naprave - Akustika - Ugotavljanje dinamične togosti elastičnih tirničnih komponent v povezavi s hrupom in vibracijami - Sestavi tirničnih podlag in tirnih pritrdilnih elementov

Ta evropski standard določa laboratorijske preskusne postopke za določanje dinamične togosti elastičnih tirničnih komponent z namenom vrednotenja okoljskega hrupa in vibracij.
Ta standard se uporablja za celotne sklope tirnih pritrdilnih elementov in za tirnične podlage sistemov za pritrditev.
Uporablja se za primerke enojnega pritrdilnega elementa tirničnega podstavka.
Uporablja se za merjenje tangentne, dinamične togosti pod predpisano predobremenitvijo in s tem povezanega histereznega faktorja izgube pri dušenju.
Zagotavlja merilne metode in pogoje predobremenitve, vzbujanja in frekvenčnega območja za uporabo pri hrupu, ki se prenaša s tal in struktur, ter kotalnem hrupu.
Zagotavlja merilne metode in pogoje predobremenitve, vzbujanja in frekvenčnega območja za uporabo pri hrupu, ki se prenaša s tal in struktur, ter kotalnem hrupu.
Ne uporablja se za merjenje togosti podlag in pritrdilnih elementov pri statični ali nizkofrekvenčni dinamični obremenitvi, ki je določena v standardu EN 13146-9.

General Information

Status
Published
Public Enquiry End Date
30-Jun-2020
Publication Date
07-Sep-2022
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
08-Sep-2022
Due Date
13-Nov-2022
Completion Date
08-Sep-2022

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SLOVENSKI STANDARD
SIST EN 17495:2022
01-november-2022
Železniške naprave - Akustika - Ugotavljanje dinamične togosti elastičnih tirničnih
komponent v povezavi s hrupom in vibracijami - Sestavi tirničnih podlag in tirnih
pritrdilnih elementov
Railway Applications - Acoustics - Determination of the dynamic stiffness of elastic track
components related to noise and vibration - Rail pads and rail fastening assemblies
Bahnanwendungen - Akustik - Bestimmung der dynamischen Steifigkeit von elastischen
Komponenten im Oberbau in Bezug auf Schall und Schwingungen - Zwischenlagen und
Schienenbefestigungssysteme
Applications ferroviaires - Acoustique - Détermination de la raideur dynamique des
composants élastiques de la voie pour le bruit et les vibrations - Semelles sous rail et
systèmes de fixation du rail
Ta slovenski standard je istoveten z: EN 17495:2022
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
SIST EN 17495:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 17495:2022

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SIST EN 17495:2022


EN 17495
EUROPEAN STANDARD

NORME EUROPÉENNE

August 2022
EUROPÄISCHE NORM
ICS 17.140.30; 93.100
English Version

Railway Applications - Acoustics - Determination of the
dynamic stiffness of elastic track components related to
noise and vibration: Rail pads and rail fastening
assemblies
Applications ferroviaires - Acoustique - Détermination Bahnanwendungen - Akustik - Bestimmung der
de la raideur dynamique des composants élastiques de dynamischen Steifigkeit von elastischen Komponenten
la voie pour le bruit et les vibrations: Semelles sous rail im Oberbau in Bezug auf Schall und Schwingungen:
et systèmes de fixation du rail Zwischenlagen und Schienenbefestigungssysteme
This European Standard was approved by CEN on 3 July 2022.

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, Türkiye 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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17495:2022 E
worldwide for CEN national Members.

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SIST EN 17495:2022
EN 17495:2022 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviated terms . 6
5 General requirements . 7
5.1 General . 7
5.2 Apparatus . 7
6 Requirements for different application cases . 8
6.1 Preloads . 8
6.2 Excitation amplitudes . 9
7 Test methods . 9
7.1 General . 9
7.2 Arrangements applying to both the direct and indirect methods . 9
7.3 Direct method . 11
7.4 Indirect method . 15
8 Test report . 18
Bibliography . 19

2

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SIST EN 17495:2022
EN 17495:2022 (E)
European foreword
This document (EN 17495:2022) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
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 February 2023, and conflicting national standards shall
be withdrawn at the latest by February 2023.
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.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, Türkiye and the United
Kingdom.
3

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SIST EN 17495:2022
EN 17495:2022 (E)
Introduction
Airborne rolling noise and structure-borne noise that propagates through the ground and rolling stock,
are excited during rolling wheel-rail interaction by the acoustic roughness (see EN 15610) of the wheel
and rail surfaces. For this reason, models for railway noise and vibration use a measure of track-support
stiffness determined at amplitudes of vibration caused by acoustic roughness and under the load of a
train and/or the rail fastening system.
This document sets out requirements for a laboratory measurement of the dynamic stiffness of rail pads
and rail fastening assemblies relevant to noise and vibration models.
The purpose is to provide data for assessment and specification of the acoustic performance of track
components.
An alternative technique to determine input data for rolling noise models is to measure track decay rates
according to EN 15461 (see also Bibliography [1]).
NOTE In contrast to the test methods elaborated in this document, other methods exist that can deliver values
for dynamic stiffness and loss factor of elastic components and fastening assemblies. They are not thought to attain
the quality and comparability required for standardization and they are not within the scope or content of this
document. For more information on these methods, see Bibliography [2 – 6].
4

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SIST EN 17495:2022
EN 17495:2022 (E)
1 Scope
This document specifies laboratory test procedures to determine a high-frequency dynamic stiffness,
“acoustic stiffness”, of resilient components of rail fastening assemblies.
This document is applicable to complete rail fastening assemblies and to pad components of fastening
systems including both discrete and continuous fastening systems.
It is applicable to the measurement of the dynamic transfer stiffness under a prescribed pre-load and the
associated hysteretic damping loss factor.
It provides measurement methods and pre-load, excitation and frequency range conditions for
application to ground borne and structure borne noise as well as for rolling noise.
It is not applicable to the measurement of the stiffness of pads and fastening assemblies under static or
low-frequency dynamic loading used for track mechanics.
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 13481-1, Railway applications - Track - Performance requirements for fastening systems - Part 1:
Definitions
EN ISO 7500-1:2018, Metallic materials - Calibration and verification of static uniaxial testing machines -
Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system
(ISO 7500-1:2018)
EN ISO 10846-1, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer properties of
resilient elements - Part 1: Principles and guidelines (ISO 10846-1)
EN ISO 10846-2, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer properties of
resilient elements - Part 2: Direct method for determination of the dynamic stiffness of resilient supports for
translatory motion (ISO 10846-2)
EN ISO 10846-3, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer properties of
resilient elements - Part 3: Indirect method for determination of the dynamic stiffness of resilient supports
for translatory motion (ISO 10846-3)
ISO 7626-1:2011, Mechanical vibration and shock — Experimental determination of mechanical mobility
— Part 1: Basic terms and definitions, and transducer specifications
ISO 16063-21, Methods for the calibration of vibration and shock transducers — Part 21: Vibration
calibration by comparison to a reference transducer
ISO 21948, Coated abrasives — Plain sheets
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13481-1 and EN ISO 10846-1
and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
5

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SIST EN 17495:2022
EN 17495:2022 (E)
3.1
acoustic stiffness
dynamic stiffness of an elastic track support component or fastening assembly that is measured under a
static preload and at small amplitudes of displacement or velocity applied in the frequency range relevant
to noise or vibration perception
Note 1 to entry: It is the measure of stiffness addressed by this document for use in noise and vibration models.
3.2
acoustic damping
loss factor associated with the acoustic stiffness
4 Symbols and abbreviated terms
For the purposes of this document, the symbols in Table 1 apply.
Table 1 — Symbols
Relevant
Symbol Meaning
subclause
2
a acceleration of the upper mass (input), in m/s
7.3.2
1
acceleration of the force-measuring platform or lower mass
a
7.3.2
2
2
(output), in m/s
force on the measuring platform (output) in the direct
F 7.3.2
2
measurement method, in N
j 7.3.2
−1
kA acoustic stiffness, in N/m 7.3.5
k transfer stiffness measured by the direct method, in N/m 7.3.2
D
k transfer stiffness measured by the indirect method, in N/m 7.4.2
I
lower isolators combined support stiffness in the indirect
k 7.4.2
L
method, in N/m
mass of the measuring platform and any parts of the 7.3.2
fastening assembly below the resilient element in the direct
m
2
method,
or the blocking mass in the indirect method, in kg 7.4.2
η acoustic loss factor, (dimensionless) 7.3.5
A
2
u displacement of the upper mass =−a /ω , in m
7.3.2
1 1
displacement of the lower mass in the indirect method
u
7.3.2
2
2
, in m
=−a /ω
2
v excitation velocity =aj/ ω , in m/s
7.3.2
1 1
ω angular frequency, in rad/s 7.3.2
NOTE The subscript 1 denotes a quantity at the input and subscript 2 denotes a quantity at the output side of
the test specimen.
6

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SIST EN 17495:2022
EN 17495:2022 (E)
5 General requirements
5.1 General
Good quality measurements depend upon the competence of the measurement team, control of the
environmental conditions, estimation of measurement uncertainties, measurement traceability, control
of data, handling of samples, and the reporting of results.
NOTE Guidance is provided in EN ISO/IEC 17025:2017.
5.2 Apparatus
5.2.1 General
The test equipment shall conform to the following requirements in order to produce repeatable results
over the frequency range and applied loads specified in this document. In particular, the following
requirements shall be applied for the transducers used.
5.2.2 Accelerometers
Accelerometers shall be calibrated at the laboratory temperature in the frequency range of interest and
shall have a sensitivity level which is frequency independent to within 0,5 dB and the sensitivity to cross-
axis accelerations shall be smaller than 5 % of the main axis of sensitivity. Calibration shall be carried out
according to ISO 16063-21.
All accelerometers used shall have an internal resonance frequency at least twice the upper limit of the
working frequency range.
Where measurements are summed from multiple accelerometers, the measurement resulting from the
whole transducer and signal acquisition system shall conform to the requirements stated above.
5.2.3 Force transducers
Force transducers used for the measurement of the dynamic force shall be calibrated in the frequency
range and temperature range of interest and have a sensitivity level which is frequency independent to
within 0,5 dB and the sensitivity to cross-axis forces shall be smaller than 5 %. Calibration shall be carried
out according to the mass-loading technique as described in ISO 7626-1:2011.
If the transducer has an associated sensitivity-level function to compensate for its variation of sensitivity
with force amplitude, the effective calibration of the system shall meet the 0,5 dB requirement.
All force transducers used for the measurement of dynamic force shall have an internal resonance
frequency at least twice the upper limit of the working frequency range.
Where measurements are summed from multiple force transducers, the measurement resulting from the
whole transducer and signal acquisition system shall conform to the requirements stated above.
Force transducers used for the measurement of the static preload shall be calibrated over the working
range to Class 1 according to EN ISO 7500-1:2018.
5.2.4 Signal acquisition and processing equipment
The spectral resolution shall provide at least one discrete frequency in each one-third-octave band in
which the result is required.
5.2.5 Load applying equipment
The equipment shall be capable of maintaining the required preload over the period of the test at the set
value to within ±5 %.
7

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SIST EN 17495:2022
EN 17495:2022 (E)
5.2.6 Temperature environment
Measurements shall be made within a tolerance of a particular temperature even if the measurement is
only required at nominal room temperature. A controlled environment shall therefore be provided
capable of maintaining a set temperature within the required tolerance and for sufficient time for
specimens to acclimatize to that temperature stably and for the measurement procedure to be completed.
6 Requirements for different application cases
6.1 Preloads
Different preloads and frequency ranges are required according to whether the stiffness is to be used in
the assessment of rolling noise (1), bridge noise (2) or ground borne vibration (3) (low-frequency
vibration, and “ground borne noise”). Table 2 specifies the preloads that shall be used in cases (1) to (3).
The frequency range for each case is stated as a minimum requirement and a preferred requirement.
Table 2 — Preloads used for different application cases
Minimum Preferred
frequency range frequency range
Preload
Case Component
values
(one-third (one-third octave
octave bands) bands)
 kN Hz Hz
Rolling noise / Rail pad 18
train interior rolling
Fastening
80 - 400 50 – 1 250
noise
assembly or 5
baseplate pad
(1)
18; 35; 50;
Rail pad
68
Bridge noise
80 - 400 25 – 2 000
Fastening
(2)
5; 18; 35;
assembly or
50
baseplate pad
18; 35; 50;
Rail pad
68
Ground borne noise
50 - 200 10 - 400
Fastening
(3)
5; 18; 35;
assembly or
50
baseplate pad
The minimum frequency range requirement should be achievable in most cases with either the direct or
indirect measurement methods set out below. The preferred frequency range reflects more closely the
requirements of acoustic calculations.
The approach sets a range of values for the preload and it is up to the user of the results to select or
interpolate from this to determine the appropriate stiffness value for the rail seat load of the noise or
vibration assessment.
For fasteners or pads with complicated load-deflection behaviour it may be advisory to make extra
measurements at intermediate preload values.
Higher preloads may be omitted in cases where a fastening assembly or pad is not designed to take such
high loads.
8

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SIST EN 17495:2022
EN 17495:2022 (E)
6.2 Excitation amplitudes
The amplitude of dynamic excitation imposed on the sample shall be a vibration velocity of (5 ± 2) mm/s
RMS at the frequency of the measurement. If it is required to test whether the acoustic stiffness of the
sample varies with the amplitude of imposed deformation, a second measurement shall be carried out
with a vibration velocity of (1,6 ± 0,4) mm/s RMS.
It shall be demonstrated that the amplitude of excitation at each frequency of the test has been achieved
within the specified range.
NOTE These excitation velocity amplitudes correspond to the order of magnitude of vibration induced by the
acoustic roughness of the wheel and rail running surfaces (see e.g. [11]).
7 Test methods
7.1 General
In this document, two different measurement methods are specified. They are termed the “direct
method”, and the “indirect method” following the terms used in EN ISO 10846-2 and EN ISO 10846-3 in
whi
...

SLOVENSKI STANDARD
oSIST prEN 17495:2020
01-junij-2020
Železniške naprave - Akustika - Ugotavljanje dinamične togosti elastičnih tirničnih
komponent v povezavi s hrupom in vibracijami - Sestavi tirničnih podlag in tirnih
pritrdilnih elementov
Railway Applications - Acoustics - Determination of the dynamic stiffness of elastic track
components related to noise and vibration - Rail pads and track fastener assemblies
Bahnanwendungen - Akustik - Bestimmung der dynamischen Steifigkeit von elastischen
Komponenten im Oberbau in Bezug auf Schall und Schwingungen - Zwischenlagen und
Schienenbefestigungssysteme
Applications ferroviaires - Acoustique - Détermination de la raideur dynamique des
composants élastiques de la voie pour le bruit et les vibrations - Semelles sous rail et
systèmes de fixation de la voie
Ta slovenski standard je istoveten z: prEN 17495
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
oSIST prEN 17495:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 17495:2020

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oSIST prEN 17495:2020


DRAFT
EUROPEAN STANDARD
prEN 17495
NORME EUROPÉENNE

EUROPÄISCHE NORM

April 2020
ICS 17.140.30; 93.100
English Version

Railway Applications - Acoustics - Determination of the
dynamic stiffness of elastic track components related to
noise and vibration - Rail pads and track fastener
assemblies
Applications ferroviaires - Acoustique - Détermination Bahnanwendungen - Akustik - Bestimmung der
de la raideur dynamique des composants élastiques de dynamischen Steifigkeit von elastischen Komponenten
la voie pour le bruit et les vibrations - Semelles sous im Oberbau in Bezug auf Schall und Schwingungen -
rail et systèmes de fixation de la voie Zwischenlagen und Schienenbefestigungssysteme
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 256.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.

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.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.


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. prEN 17495:2020 E
worldwide for CEN national Members.

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oSIST prEN 17495:2020
prEN 17495:2020 (E)
Contents

European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Symbols and abbreviated terms . 7
5 General Requirements . 8
5.1 Introduction . 8
5.2 Apparatus . 8
6 Requirements for different application cases . 9
6.1 Preloads . 9
6.2 Excitation amplitudes . 10
7 Test methods . 10
7.1 General . 10
7.2 Arrangements applying to both the direct and indirect methods . 10
7.3 Direct method . 11
7.4 Indirect method . 15
8 Test report . 18
Bibliography . 19


2

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oSIST prEN 17495:2020
prEN 17495:2020 (E)
European foreword
This document (prEN 17495:2020) has been prepared by Technical Committee CEN/TC 256 “Railway
Applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
3

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oSIST prEN 17495:2020
prEN 17495:2020 (E)
Introduction
Airborne rolling noise and structure-borne noise that propagates through the ground, are excited
during rolling wheel-rail interaction by the acoustic roughness (see EN 15610) of the wheel and rail
surfaces. For this reason, models for railway noise and vibration use a measure of track-support
stiffness determined at amplitudes of vibration caused by acoustic roughness and under the load of a
train and/or the track fastener system.
This document sets out requirements for a laboratory measurement of the dynamic stiffness of rail pads
and fasteners relevant to noise and vibration models.
An alternative technique to determine input data for rolling noise models is to measure track decay
rates according to EN 15461 (see also Bibliography [1]).
NOTE In contrast to the test methods elaborated in this document, other methods exist that can deliver
values for dynamic stiffness and loss factor of elastic components and fastening systems. They are not thought to
attain the quality and comparability required for standardization and they are not within the scope or content of
this standard. For more information on these methods, see Bibliography [2 – 6].
4

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oSIST prEN 17495:2020
prEN 17495:2020 (E)
1 Scope
This document specifies laboratory test procedures to determine a high-frequency dynamic stiffness,
“acoustic stiffness”, of resilient components. The purpose is to provide data for assessment and
specification of the acoustic performance of track components.
This document is applicable to complete track fastening assemblies and to pad components of fastening
systems including both discrete and continuous fastening systems.
It is applicable to specimens of a single rail seat fastener.
It is applicable to the measurement of the dynamic transfer stiffness under a prescribed pre-load and
the associated hysteretic damping loss factor.
It provides measurement methods and pre-load, excitation and frequency range conditions for
application to ground borne and structure borne noise as well as for rolling noise.
It is not applicable to the measurement of the stiffness of pads and fastening assemblies under static or
low frequency dynamic loading used for track mechanics and which is specified in EN 13146-9.
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 13481-1:2012, Railway applications - Track - Performance requirements for fastening systems - Part
1: Definitions
EN ISO 7500-1:2018, Metallic materials - Calibration and verification of static uniaxial testing machines -
Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system
(ISO 7500-1:2018)
EN ISO 10846-1:2008, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer
properties of resilient elements - Part 1: Principles and guidelines (ISO 10846-1:2008)
EN ISO 10846-2:2008, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer
properties of resilient elements - Part 2: Direct method for determination of the dynamic stiffness of
resilient supports for translatory motion (ISO 10846-2:2008)
EN ISO 10846-3:2002, Acoustics and vibration - Laboratory measurement of vibro-acoustic transfer
properties of resilient elements - Part 3: Indirect method for determination of the dynamic stiffness of
resilient supports for translatory motion (ISO 10846-3:2002)
ISO 7626-1:2011, Mechanical vibration and shock — Experimental determination of mechanical mobility
— Part 1: Basic terms and definitions, and transducer specifications
ISO 16063-21:2003+A1:2016, Methods for the calibration of vibration and shock transducers — Part 21:
Vibration calibration by comparison to a reference transducer
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3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13481-1 and EN ISO 10846-1
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
acoustic stiffness
dynamic stiffness of an elastic track support component or fastening assembly that is measured under a
static preload and at small amplitudes of displacement or velocity applied in the frequency range
relevant to noise or vibration perception. It is the measure of stiffness addressed by this document for
use in noise and vibration models
3.2
acoustic damping
loss factor associated with the acoustic stiffness
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4 Symbols and abbreviated terms
For the purposes of this document, the following symbols apply.
Table 1 — Symbols
Relevant
Symbol Meaning
subclause
η acoustic loss factor, (dimensionless) 7.3.5
A
ω angular frequency in rad/s 7.3.2
2
a acceleration of the upper mass (input), in m/s 7.3.2
1
a acceleration of the force-measuring platform or lower mass 7.3.2
2
2
(output), in m/s
F force on the measuring platform (output) in the direct 7.3.2
2
measurement method, in N
j √-1 7.3.2
k acoustic stiffness, in N/m 7.3.5
A
k transfer stiffness measured by the direct method, in N/m 7.3.2
D
k transfer stiffness measured by the indirect method, in N/m 7.4.2
I
k lower isolators combined support stiffness in the indirect 7.4.2
L
method, in N/m
m mass of the measuring platform and any parts of the 7.3.2
2
fastening assembly below the resilient element in the direct
method,
or the blocking mass in the indirect method, in kg 7.4.2
2
u 7.3.2
1
displacement of the upper mass =−a /ω , in m
1
u displacement of the lower mass in the indirect method 7.3.2
2
2
=−a /ω , in m
2
7.3.2
v excitation velocity = aj/ ω , in m/s
1 1
NOTE The subscript 1 denotes a quantity at the input and subscript 2 denotes a quantity at the output side of
the test specimen.
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5 General Requirements
5.1 Introduction
Good quality measurements depend upon the: competence of the measurement team, control of the
environmental conditions, estimation of measurement uncertainties, measurement traceability, control
of data, handling of samples, and the reporting of results.
NOTE Guidance is provided in EN ISO/IEC 17025:2005.
5.2 Apparatus
The test equipment shall conform to the following requirements in order to produce repeatable results
over the frequency range and applied loads specified in this document. In particular the following
requirements shall be applied for the transducers used.
5.2.1 Accelerometers
Accelerometers shall be calibrated at the laboratory temperature in the frequency range of interest and
shall have a sensitivity level which is frequency independent to within 0,5 dB and the sensitivity to
cross-axis accelerations shall be smaller than 5 % of the main axis of sensitivity. Calibration shall be
carried out according to ISO 16063-21:2003+A1:2016.
All accelerometers used shall have an internal resonance frequency at least twice the upper limit of the
working frequency range.
Where measurements are summed from multiple accelerometers, the measurement resulting from the
whole transducer and signal acquisition system shall conform to the requirements stated above.
5.2.2 Force transducers
Force transducers used for the measurement of the dynamic force shall be calibrated in the frequency
range and temperature range of interest and have a sensitivity level which is frequency independent to
within 0,5 dB and the sensitivity to cross-axis forces shall be smaller than 5 %. Calibration shall be
carried out according to the mass-loading technique as described in ISO 7626-1:2011.
If the transducer has an associated sensitivity-level function to compensate for its variation of
sensitivity with force amplitude the effective calibration of the system shall meet the 0,5 dB
requirement.
All force transducers used for the measurement of dynamic force shall have an internal resonance
frequency at least twice the upper limit of the working frequency range.
Where measurements are summed from multiple force transducers, the measurement resulting from
the whole transducer and signal acquisition system shall conform to the requirements stated above.
Force transducers used for the measurement of the static preload shall be calibrated over the working
range to Class 1 according to EN ISO 7500-1:2018.
5.2.3 Signal acquisition and processing equipment
The spectral resolution shall provide at least one discrete frequency in each one-third-octave band in
which the result is required.
5.2.4 Load applying equipment
The equipment shall be capable of maintaining the required preload over the period of the test at the
set value to within ± 10 %.
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5.2.5 Temperature environment
Measurements shall be made within a tolerance of a particular temperature even if the measurement is
only required at nominal room temperature. A controlled environment shall therefore be provided
capable of maintaining a set temperature within the required tolerance and for sufficient time for
specimens to acclimatize to that temperature stably and for the measurement procedure to be
completed.
6 Requirements for different application cases
6.1 Preloads
Different preloads and frequency ranges are required according to whether the stiffness is to be used in
the assessment of (1) rolling noise, (2) bridge noise or (3) ground borne vibration (low frequency
vibration, and “groundborne noise”). Table 1 specifies the preloads that shall be used in cases (1) to (3).
The frequency range for each case is stated as a minimum requirement and a preferred requirement.
Table 2 — Preloads used for different application cases
Minimum
Preferred
frequency
frequency
range
range
Case Component Preload values
(one-third
(one-third
octave
octave bands)
bands)
Rail pad 18 kN
Rolling noise
50 Hz to
Assembly or
80 to 400 Hz
1,25 kHz
(1)
baseplate 5 kN
pad
Rail pad 18, 35, 50, 68 kN
Bridge noise
Assembly or
80 to 400 Hz 25 Hz to 2 kHz
(2)
baseplate 5, 18, 35, 50 kN
pad
Rail pad 18, 35, 50, 68 kN
Ground
vibration/ground
Assembly or
50 to 200 Hz 10 to 400 Hz
borne noise
baseplate 5, 18, 35, 50 kN
(3)
pad
The minimum frequency range requirement should be achievable in most cases with either the direct or
indirect measurement methods set out below. The preferred frequency range reflects more closely the
requirements of acoustic calculations.
NOTE 1 The approach sets a range of values for the preload and it is up to the user of the results to select or
interpolate from this to determine the appropriate stiffness value for the rail seat load of the noise or vibration
assessment.
NOTE 2 For fasteners or pads with complicated load-deflection behaviour it may be advisory to make extra
measurements at intermediate preload values.
NOTE 3 Higher preloads may be omitted in cases where a fastener or pad is not designed to take such high
loads.
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6.2 Excitation amplitudes
The amplitude of dynamic excitation imposed on the sample shall be a vibration velocity of
(5 ± 2) mm/s RMS at the frequency of the measurement. If it is required to test whether th
...

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