SIST EN ISO 10846-4:2004

SLOVENSKI STANDARD
01-januar-2004
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Acoustics and vibration - Laboratory measurement of vibro-acyustic transfer properties of
resilient elements - Part 4: Dynamic stiffness of elements other than resilient supports for
translatory motion (ISO 10846-4:2003)
Akustik und Schwingungstechnik - Laborverfahren zur Messung der vibro-akustischen
Transfereigenschaften elastischer Elemente - Teil 4: Bestimmung der dynamischen
Transfersteifigkeit von elastischen Elementen mit Ausnahme elastischer Stützelemente
für translatorische Schwingungen (ISO 10846-4:2003)
Acoustique et vibrations - Mesurage en laboratoire des propriétés de transfert vibro-
acoustique des éléments élastiques - Partie 4: Raideur dynamique en translation des
éléments autres que les supports élastiques (ISO 10846-4:2003)
Ta slovenski standard je istoveten z: EN ISO 10846-4:2003
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
17.160 Vibracije, meritve udarcev in Vibrations, shock and
vibracij vibration measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 10846-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2003
ICS 17.140.01
English version
Acoustics and vibration - Laboratory measurement of vibro-
acyustic transfer properties of resilient elements - Part 4:
Dynamic stiffness of elements other than resilient supports for
translatory motion (ISO 10846-4:2003)
Acoustique et vibrations - Mesurage en laboratoire des Akustik und Schwingungstechnik - Laborverfahren zur
propriétés de transfert vibro-acoustique des éléments Messung der vibro-akustischen Transfereigenschaften
élastiques - Partie 4: Raideur dynamique en translation des elastischer Elemente - Teil 4: Bestimmung der
éléments autres que les supports élastiques (ISO 10846- dynamischen Transfersteifigkeit von elastischen Elementen
4:2003) mit Ausnahme elastischer Stützelemente für translatorische
Schwingungen (ISO 10846-4:2003)
This European Standard was approved by CEN on 1 August 2003.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10846-4:2003 E
worldwide for CEN national Members.

Foreword
This document (EN ISO 10846-4:2003) has been prepared by Technical Committee ISO/TC 43
"Acoustics" in collaboration with Technical Committee CEN/TC 211 "Acoustics", the secretariat
of which is held by DS.
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 March 2004, and conflicting national
standards shall be withdrawn at the latest by March 2004.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and
the United Kingdom.
NOTE FROM CMC  The foreword is susceptible to be amended on reception of the German
language version. The confirmed or amended foreword, and when appropriate, the normative
annex ZA for the references to international publications with their relevant European
publications will be circulated with the German version.
Endorsement notice
The text of ISO 10846-4:2003 has been approved by CEN as EN ISO 10846-4:2003 without any
modifications.
INTERNATIONAL ISO
STANDARD 10846-4
First edition
2003-09-01
Acoustics and vibration — Laboratory
measurement of vibro-acoustic transfer
properties of resilient elements —
Part 4:
Dynamic stiffness of elements other than
resilient supports for translatory motion
Acoustique et vibrations — Mesurage en laboratoire des propriétés de
transfert vibro-acoustique des éléments élastiques —
Partie 4: Raideur dynamique en translation des éléments autres que les
supports élastiques
Reference number
ISO 10846-4:2003(E)
©
ISO 2003
ISO 10846-4:2003(E)
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ii © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 2
3 Terms and definitions. 3
4 Principles. 5
5 Test arrangements. 6
5.1 General. 6
5.2 Local coordinate systems. 6
5.3 Test rig components. 6
5.4 Suppression of unwanted vibrations. 8
6 Criteria for adequacy of the test arrangement.19
6.1 Frequency range. 19
6.2 Measurement of blocking force in the direct method . 20
6.3 Determination of upper frequency limit f in the indirect method . 20
6.4 Flanking transmission. 23
6.5 Unwanted input vibrations. 23
6.6 Accelerometers. 24
6.7 Force transducers. 24
6.8 Summation of signals. 24
6.9 Analysers. 25
7 Test procedures. 25
7.1 Installation of the test elements . 25
7.2 Selection of force measurement system and force distribution plates . 25
7.3 Mounting and connection of accelerometers . 25
7.4 Mounting and connection of the vibration exciter . 25
7.5 Source signal. 26
7.6 Measurements. 26
7.7 Test for linearity . 27
8 Evaluation of test results . 28
8.1 Evaluation of dynamic transfer stiffness for direct method. 28
8.2 Calculation of dynamic transfer stiffness for indirect method . 28
8.3 One-third-octave-band values of the frequency-averaged dynamic transfer stiffness. 28
8.4 Presentation of one-third-octave-band results. 29
8.5 Presentation of narrow-band data. 30
9 Information to be recorded . 30
10 Test report. 31
Annex A (informative) Transfer stiffness related to rotatory vibration components . 32
Bibliography . 33

ISO 10846-4:2003(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 10846-4 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise, in
collaboration with ISO/TC 108, Mechanical vibration and shock.
ISO 10846 consists of the following parts, under the general title Acoustics and vibration — Laboratory
measurement of vibro-acoustic transfer properties of resilient elements:
 Part 1: Principles and guidelines
 Part 2: Dynamic stiffness of elastic supports for translatory motion — Direct method
 Part 3: Indirect method for determination of the dynamic stiffness of resilient supports for translatory
motion
 Part 4: Dynamic stiffness of elements other than resilient supports for translatory motion
 Part 5: Driving point method for the determination of the low frequency dynamic stiffness of elastic
supports for translatory motion
iv © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
Introduction
Passive vibration isolators of various kinds are used to reduce the transmission of vibrations. Examples are
automobile engine mounts, resilient supports for buildings, resilient mounts and flexible shaft couplings for
shipboard machinery, and small isolators in household appliances.
This part of ISO 10846 specifies a direct and an indirect method for measuring the dynamic transfer stiffness
function of linear resilient elements (other than resilient supports) such as resilient bellows, hoses, shaft
couplings, power supply cables and pipe hangers. This part of ISO 10846 belongs to a series of International
Standards on methods for the laboratory measurement of the vibro-acoustic properties of resilient elements,
which also includes documents on measurement principles and on a direct, an indirect and a driving point
method for resilient supports. ISO 10846-1 provides global guidance for the selection of the appropriate
International Standard.
The laboratory conditions described in this part of ISO 10846 include the application of static preload, where
appropriate.
The results of the method described in this part of ISO 10846 are useful for resilient elements that are used to
reduce the transmission of structure-borne sound (primarily frequencies above 20 Hz). The method does not
characterize completely elements that are used to attenuate low-frequency vibration or shock excursions.

INTERNATIONAL STANDARD ISO 10846-4:2003(E)

Acoustics and vibration — Laboratory measurement of vibro-
acoustic transfer properties of resilient elements —
Part 4:
Dynamic stiffness of elements other than resilient supports for
translatory motion
1 Scope
This part of ISO 10846 specifies two methods for determining the dynamic transfer stiffness for translations of
resilient elements other than resilient supports. Examples are resilient bellows, shaft couplings, power supply
cables, hoses and pipe hangers (see Figure 1). Elements filled with liquids, such as oil or water, are excluded.
NOTE 1 Pipe hangers are extensionally deflected, as opposed to elastic supports which are compressed. Therefore,
the test conditions are different from those described in ISO 10846-2 and ISO 10846-3.
The methods are applicable to resilient elements with flat flanges or flat clamp interfaces. It is not necessary
that the flanges be parallel.
Resilient elements which are the subject of this part of ISO 10846 are those that are used to reduce
a) the transmission of audiofrequency vibrations (structure-borne sound, 20 Hz to 20 kHz ) to a structure
which may, for example, radiate unwanted sound (airborne, waterborne or other), and
b) the transmission of low-frequency vibrations (typically 1 Hz to 80 Hz), which may, for example, act upon
human subjects or cause damage to structures of any size when the vibration is too severe.
In practice, the size of the available test rig(s) determines restrictions for very small and for very large resilient
elements.
Measurements for translations normal and transverse to the flanges or clamp interfaces are covered in this
part of ISO 10846. Annex A provides guidance for the measurement of transfer stiffnesses that include
rotatory components.
The direct method can be applied in the frequency range from 1 Hz up to a frequency that is usually
determined by the lowest resonance frequency of the test arrangement frame (typically 300 Hz for test rigs
with dimensions of the order of 1 m).
NOTE 2 In practice, the lower frequency limit depends on the dynamic excitation system.
The indirect method covers a frequency range that is determined by the test set-up and the isolator under test.
The range is typically from a lower frequency between 20 Hz and 50 Hz, to an upper frequency between
2 kHz and 5 kHz.
The data obtained according to the methods specified in this part of ISO 10846 can be used for
 product information provided by manufacturers and suppliers,
 information during product development,
 quality control, and
 calculation of the transfer of vibration through resilient elements.
ISO 10846-4:2003(E)
a) Power cable including connector and clamping device b) Pipe hanger
Key
1 connector
2 cable
3 clamp
4 fixture
5 flexible element
6 pipe clamp
Figure 1 — Examples of resilient elements with flat flanges or clamps
2 Normative references
The following referenced documents are indispensable for the application 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 266, Acoustics  Preferred frequencies

ISO 2041, Vibration and shock  Vocabulary
ISO 5348, Mechanical vibration and shock  Mechanical mounting of accelerometers
ISO 7626-1, Vibration and shock  Experimental determination of mechanical mobility  Part 1: Basic
definitions and transducers
ISO 7626-2, Vibration and shock  Experimental determination of mechanical mobility  Part 2:
Measurements using single-point translation excitation with an attached vibration exciter
ISO 10846-1, Acoustics and vibration  Laboratory measurement of vibro-acoustic transfer properties of
resilient elements  Part 1: Principles and guidelines
ISO 16063-21, Methods for the calibration of vibration and shock transducers  Part 21: Vibration calibration
by comparison with a reference transducer
GUM:1993, Guide to the expression of uncertainty in measurement. BIPM/IEC/IFCC/ISO/IUPAC/IUPAP/OIML
2 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041 and the following apply.
3.1
resilient element
element of which one of the functions is the reduction of the vibration transmission in a certain frequency
range
3.2
resilient support
resilient element suitable for supporting part of the mass of a machine, a building or another type of structure
3.3
test element
resilient element under test, including flanges and auxiliary fixtures, if any
3.4
blocking force
F
b
dynamic force on the output side of a resilient element which results in zero displacement output
3.5
dynamic transfer stiffness
k
2,1
frequency-dependent ratio of the complex blocking force F on the output side of a resilient element to the
2,b
complex displacement u on the input side during simple harmonic motion, defined by the following formula
k = F /u
2,1 2,b 1
NOTE The value of k can be dependent upon the static preload, temperature and other conditions.
2,1
3.6
loss factor of resilient element
η
ratio of the imaginary part of k and the real part of k (i.e. tangent of the phase angle of k ) in the low-
2,1 2,1 2,1
frequency range where inertial forces in the element are negligible
3.7
frequency-averaged dynamic transfer stiffness
k
av
function of the frequency of the average value of the modulus of the dynamic transfer stiffness over a
frequency band ∆f
NOTE See 8.3.
3.8
point contact
contact area which vibrates as the surface of a rigid body
3.9
normal translation
translational vibration normal to the flange of a resilient element
3.10
transverse translation
translational vibration in a direction perpendicular to that of the normal translation
ISO 10846-4:2003(E)
3.11
linearity
property of the dynamic behaviour of a resilient element, if it satisfies the principle of superposition
NOTE 1 The principle of superposition can be stated as follows. If an input x (t) produces an output y (t) and in a
1 1
separate test an input x (t) produces an output y (t), superposition holds if the input a·x (t) + b·x (t) produces the output
2 2 1 2
a·y (t) + b·y (t). This must hold for all values of a, b and x (t) and x (t); a and b are arbitrary constants.
1 2 1 2
NOTE 2 In practice, the above test for linearity is impractical and a limited check of linearity is done by measuring the
dynamic transfer stiffness for a range of input levels. In effect this procedure checks for a proportional relationship
between the response and the excitation (see 7.7).
3.12
direct method
method in which the input displacement, velocity or acceleration and the blocking output force are measured
3.13
indirect method
method in which the vibration transmissibility (for displacement, velocity or acceleration) of a resilient element
is measured, with the output loaded by a compact body of known mass
3.14
transmissibility
T
ratio of the complex displacements on the output side u to those on the input side u of the test element

2 1
during simple harmonic motion, defined by the following formula
T = u /u
2 1
NOTE For velocities v and accelerations a, transmissibilities are defined in a similar way and have the same value.
3.15
force level
L
F
level calculated by the following formula
F
L = 10 lg dB
F
F
2 −6
where F denotes the mean square value of the force in a specific frequency band and F = 10 N is the
reference force
3.16
acceleration level
L
a
level calculated by the following formula
a
L = 10 lg dB
a
a
2 −6 2
where a denotes the mean square value of the acceleration in a specific frequency band and a = 10 m/s
is the reference acceleration
3.17
4 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
level of dynamic transfer stiffness
L
k
2,1
level calculated by the following formula
k
21,
= 10 lg dB
L
k
21,
k
where |k | is the square magnitude of the dynamic transfer stiffness (see 3.5) at a specified frequency and
2,1
. −1
k denotes the reference stiffness ( = 1 N m )
3.18
level of frequency-band-averaged dynamic transfer stiffness
L
k
av
level calculated by the following formula
k
av
L = 10 lg dB
k
av
k
. −1
where k is defined in 3.7 and k denotes the reference stiffness ( = 1 N m )
av 0
3.19
flanking transmission
transmission of vibrations to the output side via paths other than through the resilient element under test
4 Principles
The measurement principles of the direct and the indirect method are discussed in ISO 10846-1.
In the direct method, the basic principle is that the blocking output force is measured between the output side
of the resilient element and a foundation. The foundation shall provide a sufficient reduction of the vibrations
on the output side of the test object compared to those on the input side.
In the indirect method the basic principle is that the blocking output force is derived from acceleration
measurements on a compact body of mass m , which provides sufficiently small vibrations on the output side
of the test element. This blocking mass shall be dynamically decoupled from the other parts of the test
arrangement to prevent flanking transmission.
For sinusoidal vibration and using complex notation, the relationship between the dynamic transfer stiffness of
the element under test and the measured vibration transmissibility (3.14) is given by the following
approximation
k ≈ − (2πf ) (m + m )T for | T | << 1 (1)
2,1 2 f
where m denotes the mass of the output flange of the test element. The indices “1” and “2” denote the input
f
and output side, respectively.
A valid indirect determination of a blocking force according to the right-hand term of Equation (1) requires that
this blocking force solely determines the corresponding vibration measured on the blocking mass. Therefore,
in principle, the vibration to be measured is that of the centre of mass of the compact body composed of the
blocking mass and the output flange of the test element, and in the direction of the wanted force.
ISO 10846-4:2003(E)
5 Test arrangements
5.1 General
In Figures 2 to 8, examples are given of test arrangements for resilient elements other than resilient supports.
The sketches are schematic. Examples are given of test arrangements for single elements as well as for
symmetrically paired ones.
NOTE The collection of examples is by no means exhaustive and is not intended to form a limitation for test
arrangement principles. It is meant as an illustration of solutions that have been applied to meet requirements for the
adequacy of the test arrangements (see Clause 6).
To be suitable for measurements according to this part of ISO 10846, a test arrangement shall include the
components given in 5.3, when applicable. Other aspects concerning test rig properties are discussed in 5.4
and 5.5.
5.2 Local coordinate systems
For the resilient elements which are tested according to this part of ISO 10846, the directions normal to
flanges or fixtures on the input and on the output side may be not the same (see Figures 7 and 8). For non-
planar test elements, they are even out-of-plane. Therefore, for each test configuration, the local Cartesian
coordinate systems and the local corresponding forces, torques, displacements and rotatory displacements
shall be defined in agreement with Figure 9. The positive directions of the z-axes shall coincide with the
directions normal to the input and output flanges and shall point away from the test element. In the case of a
"planar" test element, the x-axis shall be chosen out-of-plane on the input as well as on the output side. In the
case of a non-planar test element, the transverse axis directions shall be defined according to the
requirements of the applications. The naming of the x- and y-directions is the responsibility of the user of this
part of ISO 10846. Thus, the definition of dynamic transfer stiffnesses of cables and hoses is dependent on
the test element and on the test arrangement.
The naming of the dynamic transfer stiffnesses shall be in agreement with the following notation:
k ; k ; k
2x,1x 2x,1y 2x,1z
k ; k ; k
2y,1x 2y,1y 2y,1z
k ; k ; k
2z,1x 2z,1y 2z,1z
where the subscripts 2x, 2y, 2z refer to the local coordinate system for the blocking output forces, and the
subscripts 1x, 1y, 1z to the local coordinate system for the input displacements.
In cases where confusion is unlikely, simpler notations may be used. For example, for an axially symmetrical
test component as in Figure 2, it can suffice to define two transfer stiffnesses as follows: k (axial); k (radial).
2,1 2,1
5.3 Test rig components
5.3.1 Resilient elements under test
The test element shall be mounted in a way that is representative of its use in practice. This shall include the
static preload and the fixture arrangements on the input and output sides. Auxiliary fixtures shall be
considered as parts of the test element (see 3.3).
NOTE Resilient elements with a strongly non-linear static load deflection curve show strongly preload dependent
dynamic behaviour as well. However, in contrast to the resilient supports covered in ISO 10846-3, the static preloads in
this part of ISO 10846 are not primarily due to gravity. For example, the static preload for a resilient shaft coupling may be
a torque load [Figure 3 b)].
6 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
5.3.2 Force measurement system on the output side
When the direct method is used, the force measurement system on the output side of the resilient element
shall consist of one or more force transducers.
It may be necessary to apply a force distribution plate between the test element and the force transducers
(see Figure 8).
NOTE Besides its function of load distribution, the force distribution plate also provides a high contact stiffness to the
force transducers. Moreover, it provides a uniform vibration of the output flange or clamp.
5.3.3 Blocking mass on the output side
When the indirect method is used, one function of the blocking mass is the estimation of the blocking output
force by measuring the acceleration of the mass. A second function is to provide a spatially uniform vibration
of the output flange of the test object over the frequency range of interest.
5.3.4 Acceleration measurement systems
Accelerometers shall be mounted on the input and output side of the test object and on the foundation of the
test arrangement. When mid-point positions are not accessible, indirect measurement of the mid-point
accelerations shall be performed by making an appropriate signal summation, for example, by taking the
linear average for two symmetrically positioned accelerometers.
When the indirect method is used, the transverse accelerometers of the blocking mass that are needed are
those along the x- and y-axes through the centre of mass of the compact body composed of the blocking mass
and the output flange of the test element (see Figure 10).
Provided that their frequency range is appropriate, displacement or velocity transducers may be used instead
of accelerometers.
5.3.5 Dynamic excitation system
The dynamic excitation system shall be appropriate for the frequency range of interest. Any suitable type of
exciter is permitted. Examples are
a) a hydraulic exciter,
b) one or more electrodynamic vibration exciters (shakers) with connection rods, and
c) one or more piezo-electric exciters.
Vibration isolators may be used for dynamic decoupling of exciters to reduce flanking transmission.
5.3.6 Excitation mass on the input side
The excitation mass on the input side of the test object has one or more of the following functions:
a) to provide a uniform vibration of the input flange under dynamic forces;
b) to enhance unidirectional vibration of the input flange.
If the test element contains a solid-mass-type input flange, which can provide the above-mentioned functions,
the special excitation mass may be omitted.
ISO 10846-4:2003(E)
Predominantly unidirectional translation on the input side of the test element is an essential requirement for
the measurement of dynamic stiffnesses according to this part of ISO 10846 (see 6.5). The predominance of
unidirectional vibration of the input flange, will be influenced by
a) the symmetry of the vibration excitations and boundary conditions of the excitation mass [see Figure 2 b)],
and
b) the inertial properties of the excitation mass [see Figure 3 a)].
In certain cases, it will be necessary to apply external constraints, such as roller bearings or some other
guiding system, to prevent vibrations in unwanted directions.
5.4 Suppression of unwanted vibrations
5.4.1 General
The test procedures according to this part of ISO 10846 cover measurements of transfer stiffnesses for
unidirectional excitations one by one in the normal and transverse directions.
However, due to asymmetries in excitation, boundary conditions and test element properties, components
other than the intended input vibration component may show unwanted strong responses at certain
frequencies. Qualitative measures to suppress unwanted input vibrations are discussed in 5.4.2 and 5.4.3. A
special category of test arrangements is that in which two nominally equal resilient elements are tested in a
symmetrical configuration. This may help to suppress unwanted input vibrations. Quantitative requirements
are given in 6.5.
5.4.2 Normal direction
For excitation in the normal direction, symmetrical positioning of the exciter or a pair of exciters and use of an
axially symmetric excitation mass is the preferred method for suppressing transverse and rotational vibrations
on the input side.
Nevertheless, the properties of the test object itself can cause coupling between the normal and other
vibration directions. Such unwanted responses may be strongly suppressed by using an excitation mass
which has, at the interface with the test element, large driving point impedances for transverse and rotational
directions compared to the corresponding driving point impedances of the test element [see, for example,
Figure 8 a)].
Another method of suppressing unwanted input vibrations is the use of a symmetrical arrangement with two
nominally identical test objects, or of a “guiding” system on the sides of the excitation mass, for example, roller
bearings. These systems are not shown in a figure, but they are rather similar to the examples for transverse
excitation shown in Figures 2 b), 3 a) and 5.
5.4.3 Transverse direction
For excitation in the transverse direction, coupling between transverse and rotational input vibrations will
always occur.
Some examples are discussed of measures which may enhance unidirectional vibrations on the input side.
Figures 2 b), 6 and 8 d) show a symmetrical arrangement with two nominally equal test objects. Figures 3 a)
and 4 show, as examples, how a guiding system can be used to suppress input rotations. Figure 7 b) shows
an example without a guiding system. In this latter case, a symmetrical excitation block is excited along a line
through its centre of gravity. In the frequency range where the impedances of the block for transverse and
rotational directions exceed those of the test elements and of decoupling springs, the block vibrations will be
strongly unidirectional.
An alternative to the application of conventional methods might be the use of active vibration control. Using
multiple actuators and sensors in combination with a control system, the ratio between the wanted and
unwanted vibration levels can be improved.
8 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
a) Test rig in a frame and with axial excitation

b) Symmetric configuration including two nominally equal couplings and with transverse excitation
Key
1 exciter 5 blocking mass
2 excitation mass 6 dynamic decoupling springs
3 coupling flanges 7 torque preload attachments [see Figure 3 b)]
4 flexible part of coupling
Figure 2 — Examples of laboratory test rigs for measuring the dynamic transfer stiffness of a resilient
shaft coupling with static torque preload and using the indirect method
ISO 10846-4:2003(E)
a) Radial excitation for frame arrangement [see Figure 2 a)]

b) Torque preload
Key
1 exciter
2 thin force distribution plate with guiding system
3 large excitation mass with suppressed rotation
4 coupling
5 input side
6 output side
7 pneumatic cylinder
Figure 3 — Examples of details of a laboratory test rig as in Figure 2
10 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
Key
1 exciter
2 traverse
3 dynamic decoupling springs
4 excitation mass
5 test element with fixture and pipe clamp
6 solid cylinder with pipe clamps
7 blocking mass
8 controllable air spring
9 load cell
10 rigid foundation
Figure 4 — Example of laboratory test rig for measuring the dynamic transfer stiffnesses of a resilient
pipe hanger with gravity load using the indirect method
(Overview with normal excitation, the pipe hanger is mounted upside down)
ISO 10846-4:2003(E)
a) Input side, normal excitation b Input side, transverse excitation

c) Output side, normal excitation d) Output side, transverse excitation
Key
1 exciter
2 traverse
3 optional guiding system
4 acceleration measurement (a )
5 pipe clamps for excitation mass
6 pipe clamp test element
7 pipe hanger fixture
8 acceleration measurement (a )
9 acceleration measurement (a )
10 load cell
Figure 5 — Examples of details of a laboratory test rig as in Figure 4
12 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
Key
1 exciter
2 excitation mass
3 blocking mass
4 dynamic decoupling springs
5 acceleration measurement (a )
6 acceleration measurement (a )
Figure 6 — Example of laboratory test rig for measuring the dynamic transfer
stiffnesses of a resilient pipe hanger using the indirect method
(Symmetrical configuration with two nominally equal hangers)
ISO 10846-4:2003(E)
a) Overview and axial excitation

b) Transverse excitation
Key
1 exciter 8 rigid foundation
2 frame 9 cables
3 dynamic decoupling springs 10 acceleration measurement (a )
4 excitation mass 11 acceleration measurement (a )
5 connectors and cables 12 acceleration measurement (a )
6 clamp 13 input side
7 blocking mass 14 output side
Figure 7 — Example of laboratory test rig for measuring the dynamic transfer stiffnesses of an electric
cable bundle (e.g. three cables), using the indirect method
14 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
a) Output side for blocking force measurement

b) Output side for transverse measurements c) Output side for transverse measurements
with shear force measurement system with low friction guiding system

d) Symmetrical configuration of two bundles for the benefit of unidirectional transverse vibration input
Key
1 clamp 5 acceleration measurement (a )
2 output force distribution plate 6 exciter
3 force measurement system (F ) 7 blocking mass
4 rigid foundation
Figure 8 — Example of laboratory test rig for measuring the dynamic transfer stiffnesses of an electric
bundle (e.g. three cables), using the direct method
ISO 10846-4:2003(E)
Figure 9 — Cartesian coordinate system with forces, torques, translatory and rotatory displacements
16 © ISO 2003 — All rights reserved

ISO 10846-4:2003(E)
Key
1 centre of mass of the blocking mass
2 centre of mass of the flange
3 centre of mass of the compound body
NOTE 1 The distance between the centres of mass 1 and 2 equals c.
NOTE 2 The distance between the centres of mass 1 and 3 equals b.
c
b =
1/+mm
2f
Figure 10 — Example of locating the centre of mass of the compact body composed of
blocking mass and output flange of the test element
ISO 10846-4:2003(E)
5.5 Special requirements
5.5.1 Provisions for testing
According to 5.1.1, the test element shall be mounted in a way which is representative of its use in practice.
This may require special provisions for the test arrangement. The most common situations are treated in 5.5.2
to 5.5.5. In situations which are not specifically described in this part of ISO 10846, similar provisions shall be
taken. These shall be described in detail in the test report and it shall be made clear in such a report that the
test conditions are representative of those found in practice.
5.5.2 Static torque preload
The vibro-acoustic transfer properties of flexible couplings in drive shafts (e.g. in ships) are often highly
dependent on the preload. Therefore, the dynamic transfer stiffnesses shall be determined with the test object
preloaded with an appropriate static torque. Figure 3 b) shows an example of how the torque can be applied.
Static rotation of the excitation mass may be obtained by using, for example, two pneumatic or hydraulic
cylinders which are connected to the mass via dynamic decoupling springs. The rotation of the blocking mass
is restricted using dynamic decoupling springs and “foundation-mounted” stops.
In Figure 2 a) the rotation axis of the test coupling is vertical. Although this could be different from practice,
such testing is permitted as long as an unrealistic gravity preload on the flexible test element is prevented.
Use of such a “vertical” set-up can be attractive, for example, when a test frame as described in ISO 10846-3
is already available.
5.5.3 Fixtures, etc.
Test objects which have no flat flanges shall be provided with auxiliary fixtures to arrange for appropriate
connections to the excitation mass and to the blocking mass. Figures 4 to 8 show examples of a pipe hanger
and a cable bundle.
A pipe hanger shall be tested upside down. For the connection to the excitation mass, a pipe clamp shall be
used as part of the pipe hanger together w
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