ISO 18437-3:2005

Mechanical vibration and shock - Characterization of the dynamic mechanical properties of visco-elastic materials - Part 3: Cantilever shear beam method

ISO 18437-3:2005 defines a cantilever shear beam method for determining from laboratory measurements the dynamic mechanical properties of the resilient materials used in vibration isolators. Common errors due to clamping the specimen are avoided by using fixed ends so there is no rotational motion of the beam at its ends. This part of ISO 18437 is applicable to shock and vibration systems operating from a fraction of a hertz to about 20 kHz. ISO 18437-3:2005 is applicable to resilient materials that are used in vibration isolators in order to reduce -- transmissions of unwanted vibrations from machines, structures or vehicles that radiate sound (fluid-borne, airborne, structure-borne, or other), and -- the transmission of low- frequency vibrations that act upon humans or cause damage to structures or sensitive equipment when the vibration is too severe. The data obtained with the measurement methods that are outlined in ISO 18437-3:2005 are used for -- the design of efficient vibration isolators, -- the selection of an optimum material for a given design, -- the theoretical computation of the transfer of vibrations through isolators, -- information during product development, -- product information provided by manufacturers and suppliers, and -- quality control.

Vibrations et chocs mécaniques — Caractérisation des propriétés mécaniques dynamiques des matériaux visco-élastiques — Partie 3: Méthode du faisceau par cisaillement en encorbellement

General Information

• Status: Published
• Publication Date: 17-Apr-2005
• ICS: 17.160 - Vibrations, shock and vibration measurements
• Technical Committee: ISO/TC 108 - Mechanical vibration, shock and condition monitoring
• Drafting Committee: ISO/TC 108/WG 28 - Vibration materials
• Current Stage: 9060 - Close of review
• Completion Date: 02-Sep-2029

Relations

• Amended By: ISO 18437-3:2005/Amd 1:2010 - Mechanical vibration and shock - Characterization of the dynamic mechanical properties of visco-elastic materials - Part 3: Cantilever shear beam method - Amendment 1
• Effective Date: 11-Dec-2021

Overview

ISO 18437-3:2005 specifies the cantilever shear beam method for laboratory determination of the dynamic mechanical properties of visco‑elastic (resilient) materials used in vibration isolators. The method uses a fixed‑end cantilever shear beam to avoid clamping‑induced errors (no rotational motion at ends) and is applicable to shock and vibration systems from a fraction of a hertz up to about 20 kHz. Results (complex Young’s modulus, loss factor, etc.) support design, selection, modelling and quality control of vibration‑isolation materials and products.

Key topics and technical requirements

• Test principle: sinusoidal shear excitation of a beam specimen with fixed ends (cantilever shear mode) to obtain frequency‑dependent modulus and damping.
• Linearity requirement: measurements assume linear vibrational behaviour at the test strain magnitudes; checks include measuring modulus over a range of input levels.
• Time–temperature superposition: measurements at multiple temperatures (typically stepped by ~5 °C with control ~±0.5 °C) are shifted along the frequency axis to extend the usable frequency range.
• Measured quantities: complex Young’s modulus (real and imaginary parts) and loss factor (tan δ).
• Essential equipment:
  • Electro‑dynamic vibration generator (typical range 0.3–30 Hz; force >10 N; amplitude ≈100 µm)
  • Force measurement (calibrated; uncertainty <0.5 % typical)
  • Non‑contact displacement transducer (eddy‑current or optical; uncertainty <0.5 %)
  • Rigid clamping/end blocks and drive shaft to ensure fixed‑fixed deformation mode
  • Environmental chamber for temperature control and conditioning
  • Computer for data acquisition, calibration and analysis
• Procedures covered: specimen preparation and mounting, conditioning, calibration, measurement runs, temperature cycling, data presentation and test reporting.

Applications

• Design and optimization of vibration isolators, mounts and shock absorbers
• Selection of visco‑elastic materials for acoustics and vibration control (structure‑borne, airborne, fluid‑borne)
• Theoretical computation and modelling of vibration transfer through isolators
• Product development, supplier data sheets and quality control testing of resilient components
• Assessing low‑frequency vibration transmission that affects humans, equipment or structures

Who uses this standard

• Vibration and acoustics engineers
• Materials scientists and test laboratories
• Manufacturers and suppliers of vibration isolators, mounts and damping materials
• Product development and quality assurance teams in automotive, aerospace, industrial machinery and building‑isolation sectors

Related standards

• ISO 18437-2 (Resonance method)
• ISO 6721-1, ISO 4664-1, ISO 10112, ISO 10846-1, ISO 23529 (referenced guidance on terminology, specimen prep and dynamic testing)

Keywords: ISO 18437-3:2005, cantilever shear beam, visco‑elastic materials, dynamic mechanical properties, vibration isolator testing, time‑temperature superposition, loss factor, Young’s modulus.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18437-3
First edition
2005-04-15
Mechanical vibration and shock —
Characterization of the dynamic
mechanical properties of visco-elastic
materials —
Part 3:
Cantilever shear beam method
Vibrations et chocs mécaniques — Caractérisation des propriétés
mécaniques dynamiques des matériaux visco-élastiques —
Partie 3: Méthode du faisceau par cisaillement en encorbellement

Reference number
©
ISO 2005
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ii ISO 2005 – All rights reserved

Contents Page
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Test equipment (see Figure 1) . 3
4.1 Electro-dynamic vibration generator . 3
4.2 Force measurement . 3
4.3 Displacement transducer . 4
4.4 Clamping system . 4
4.5 Environmental chamber . 5
4.6 Computer . 5
5 Operating procedure . 5
5.1 Sample preparation and mounting . 5
5.2 Conditioning . 6
5.3 Cantilever shear beam analysis . 7
5.4 Calibration and measurement . 8
5.5 Number of test pieces . 8
5.6 Temperature cycle . 8
6 Analysis of results . 9
6.1 Time-temperature superposition . 9
6.2 Data presentation . 9
6.3 Test report . 10
Annex A (informative) Linearity of resilient materials . 11
Annex B (informative) Time-temperature superposition . 12
Bibliography . 14
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ISO 2005 – All rights reserved iii

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 18437-3 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock.
ISO18437 consists of the following parts, under the general title Mechanical vibration and shock —
Characterization of the dynamic mechanical properties of visco-elastic materials:
— Part 2: Resonance method
— Part 3: Cantilever shear beam method
Part 4 (Impedance method) is under preparation.
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iv ISO 2005 – All rights reserved

Introduction
Visco-elastic materials are used extensively to reduce vibration magnitudes in structural systems through the
dissipation of energy (damping) or isolation of components, and in acoustical applications that require a
modification of the reflection, transmission, or absorption of energy. Such systems often require specific
dynamic mechanical properties in order to function in an optimum manner. Energy dissipation is due to
interactions on the molecular scale and is measured in terms of the lag between stress and strain in the
material. The visco-elastic properties (modulus and loss factor) of most materials depend on frequency,
temperature and strain magnitude. The choice of a specific material for a given application determines the
system performance. The goal of this part of ISO 18437 is to provide details on the principle of operation of a
cantilever shear beam method that avoids common clamping errors through the use of fixed ends, the
measurement equipment, in performing the measurements, and analysing the resultant data. A further intent is
to assist users of this method and to provide uniformity in the use of this method. This part of ISO 18437 applies
to the linear behaviour observed at small strain magnitudes.
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ISO 2005 – All rights reserved v

INTERNATIONAL STANDARD ISO 18437-3:2005(E)
Mechanical vibration and shock — Characterization of the
dynamic mechanical properties of visco-elastic materials —
Part 3:
Cantilever shear beam method
1Scope
This part of ISO 18437 defines a cantilever shear beam method for determining from laboratory measurements
the dynamic mechanical properties of the resilient materials used in vibration isolators. Common errors due to
clamping the specimen are avoided by using fixed ends so there is no rotational motion of the beam at its ends.
This part of ISO 18437 is applicable to shock and vibration systems operating from a fraction of a hertz to about
20 kHz.
This part of ISO 18437 is applicable to resilient materials that are used in vibration isolators in order to reduce
a) transmissions of unwanted vibrations from machines, structures or vehicles that radiate sound (fluid-borne,
airborne, structure-borne, or others), and
b) the transmission of low-frequency vibrations that act upon humans or cause damage to structures or
sensitive equipment when the vibration is too severe.
The data obtained with the measurement methods that are outlined in this part of ISO 18437 and further
detailed in ISO 18437-2 are used for
— the design of efficient vibration isolators,
— the selection of an optimum material for a given design,
— the theoretical computation of the transfer of vibrations through isolators,
— information during product development,
— product information provided by manufacturers and suppliers, and
— quality control.
The condition for the validity of the measurement method is linearity of the vibrational behaviour of the isolator.
This includes elastic elements with nonlinear static load deflection characteristics, provided that the elements
show approximate linearity in their vibrational behaviour for a given static preload.
Measurements using this method are made over two decades in frequency (typically 0,3 Hz to 30 Hz) at a
number of temperatures. By applying the time-temperature superposition principle, the measured data are
−3
shifted to generate dynamic mechanical properties over a much wider range of frequencies (typically 10 Hz
to 10 Hz at a single reference temperature) than initially measured at a given temperature.
NOTE For the purpose of this part of ISO 18437, the term “dynamic mechanical properties” refers to the determination of
the fundamental elastic properties, e.g. the complex Young's modulus as a function of temperature and frequency and, if
applicable, a static preload.
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ISO 2005 – All rights reserved 1

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 472:1999, Plastics — Vocabulary
ISO 2041:1990, Vibration and shock — Vocabulary
ISO 4664-1:2005, Rubber, vulcanized or thermoplastic — Determination of dynamic properties — Part 1:
General guidance
ISO 6721-1:2001, Plastics — Determination of dynamic mechanical properties — Part 1: General principles
ISO 10112:1991, Damping materials — Graphical presentation of the complex modulus
ISO 10846-1:1997, Acoustics and vibration — Laboratory measurement of vibro-acoustic transfer properties of
resilient elements — Part 1: Principles and guidelines
ISO 23529:2004, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472, ISO 2041, ISO 4664-1,
ISO 6721-1, ISO 10112, ISO 10846-1, ISO 23529 and following terms and definitions apply.
3.1
Young's modulus
∗
E
quotient of normal stress (tensile or compressive) to resulting normal strain, or fractional change in length
NOTE 1 Unit is the pascal (Pa).
� ��
NOTE 2 Young's modulus for visco-elastic materials is a complex quantity, having a real part E and an imaginary part E .
NOTE 3 Physically, the real component of Young's modulus represents elastic-stored mechanical energy. The imaginary
component is a measure of mechanical energy loss. See 3.2.
3.2
loss factor
ratio of the imaginary part of the Young's modulus of a material to the real part of the Young's modulus (the
tangent of the argument of the complex Young's modulus)
NOTE When there is energy loss in a material, the strain lags the stress by a phase angle, δ. The loss factor is equal to
tanδ.
3.3
time-temperature superposition
principle by which, for visco-elastic materials, time and temperature are equivalent to the extent that data at one
temperature are superimposed upon data taken at a different temperature merely by shifting the data curves
along the frequency axis
3.4
shift factor
measure of the amount of shift along the logarithmic (base 10) axis of frequency for one set of constant-
temperature data to superpose upon another set of data
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3.5
glass transition temperature
T
g
temperature at which a visco-elastic material changes state from glassy to rubbery, and corresponds to a
change in slope in a plot of specific volume against temperature
NOTE 1 Unit is degrees Celsius (°C).
NOTE 2 The glass transition temperature is typically determined from the inflection point of a specific heat vs. temperature
plot and represents an intrinsic material property.
NOTE 3 T is not the peak in the dynamic mechanical loss factor. That peak occurs at a higher temperature than T and
g g
varies with the measurement frequency; hence is not an intrinsic material property.
3.6
resilient material
visco-elastic material intended to reduce the transmission of vibration, shock or noise
NOTE 1 It is sometimes referred to as an elastic support, vibration isolator, shock mounting, absorber or decoupler.
NOTE 2 The reduction may be accomplished by the material working in tension, compression, torsion, shear, or a
combination of these.
3.7
linearity
property of the dynamic behaviour of a resilient material if it satisfies the principle of superposition
x (t) y (t)
NOTE 1 The principle of superposition is stated as follows: if an input produces an output and in a separate test
1 1
an input x (t) produces an output y (t), superposition holds if the input αx (t)+βx (t) produces the output
2 2 1 2
αy (t)+βy (t) αβ x (t) x (t) αβ
. This holds for all values of , and , , where and are arbitrary constants.
1 2 1 2
NOTE 2 In practice, the above test for linearity is impractical. Measuring the dynamic modulus for a range of input levels
can provide a limited check of linearity. For a specific preload, if the dynamic transfer modulus is nominally invariant, the
system measurement is considered linear. In effect this procedure checks for a proportional relationship between the
response and the excitation.
4 Test equipment (see Figure 1)
4.1 Electro-dynamic vibration generator
The vibration generator induces an oscillating sinusoidal cantilever shear strain into the sample beam at the
selected frequency. An electro-dynamic vibration generator, with the following specifications, is typical of that
required to provide a driving force for the specimen in a typical test:
— frequency range: 0,3 Hz to 30 Hz;
— force rating: > 10 N;
—amplitude: .≈ 100µm
4.2 Force measurement
Typically the force is inferred by measuring the magnitude and phase of the current driving the electro-dynamic
vibration generator. The force shall be calibrated using a known mass. The following specifications apply:
— frequency range: 0,3 Hz to 30 Hz;
—uncertainty: .< 0,5 %
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ISO 2005 – All rights reserved 3

Key
1 beam specimen
2 specimen end blocks
3 specimen clamps
4 temperature probe
5 environmental chamber
6drive shaft
7 electro-dynamic vibration generator
8 force sensor
9 displacement sensor
10 driver input
11 instrument controls for force, displacement and driver units
12 computer
13 temperature probe
NOTE The drive shaft is rigidly attached to the sample clamp and vibration generator so motion is that of a shear beam.
Figure 1 — Schematic diagram of test apparatus
4.3 Displacement transducer
To eliminate inertial effects, a non-contacting sensor (typically an eddy current type or an optical encoder that is
appropriately calibrated) with the following specifications shall be used to measure the specimen complex
displacement, magnitude and phase:
— frequency range: 0,3 Hz to 30 Hz;
—uncertainty: .< 0,5 %
4.4 Clamping system
One end of the specimen is clamped rigidly to a frame using the attached end block. (See 5.1.) The driven end
block is clamped into a fixture actuated by an electro-dynamic vibration generator via a rigid drive shaft.
The rigidity of the drive shaft and clamping fixture shall be tens to hundreds times larger that the bending
stiffness of the specimen so that all of the measured displacement may be attributed to sample deformation.
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This clamping system assures that the sample motion is confined to a cantilever shear beam mode with fixed-
fixed ends. Figure 2 shows the required mode of deformation.
While in the past it was common not to use end blocks, their use has been found necessary in order to obtain
[1]
reproducible and reliable results .
Key
1 beam specimen
2 specimen end blocks
3 specimen clamps
4drive shaft
Figure 2 — Schematic diagram of sample deformation
4.5 Environmental chamber
An environmental chamber is required to cool the test sample to a temperature below room temperature. This
temperature shall be maintained until the sample has reached equilibrium, then the temperature of the sample
◦
shall be increased in increments of typically 5 C. The chamber should be capable of operating over the
◦ ◦ ◦
temperature range from − 60C7 to 0 C and be controllable within 0,5 C. The temperature sensor shall be
appropriately calibrated.
NOTE 1 The required temperature range is appropriate for a visco-elastic material having a glass transition temperature
◦
greater than − 45 C. Materials with lower glass transition temperatures will require a lower starting temperature point.
NOTE 2 Some materials are sensitive to humidity and it may be desirable to control or at least record the relative humidity
in the chamber.
4.6 Computer
The use of a computer is advantageous to automate the calibration, data acquisition and processing.
5 Operating procedure
5.1 Sample preparation and mounting
5.1.1 General
Test specimens are typically cut from a sheet moulded or cast to the desired thickness using a small band saw
or razor. It has been found that machining specimens from a thicker sample often affects the properties of the
material. Specimens shall be uniform along each axis, and the ends shall be square to promote adhesion to the
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ISO 2005 – All rights reserved 5

end blocks. The dimensions of the specimen depend on the specific instrument and specimen stiffness. A
typical specimen is 15 mm× 10 mm×3mm.
Three properties of the specimen, which are required in the analyses, shall be measured before bonding the
specimen to the mounting blocks. In accordance with ISO 23529, determine the length, width and thickness, in
metres, to four significant digits. The dimensions shall be measured at three locations along each axis then
averaged.
5.1.2 Specimen end blocks
Steel or aluminium end blocks are attached to the ends of the specimen for clamping purposes. The actual
dimensions of the end block vary with the clamping fixture configuration, but typical dimensions are
20 mm× 15 mm×5mm for the specimen in 5.1.1.
5.1.3 Specimen preparation
The specimen is bonded to the end blocks using a rigid adhesive. The elastic modulus of the adhesive shall be
greater than that of the specimen and shall be stable over the experimental temperature range. Epoxy, urethane
and cyanoacrylate adhesives have all been used successfully. Prior to bonding, the end blocks should be
cleaned with denatured alcohol or other degreaser to promote adhesion. After the adhesive has cured,
...