ISO 22183:2023
(Main)Plastics — Validation of force-time curves obtained from high-speed tensile tests
Plastics — Validation of force-time curves obtained from high-speed tensile tests
This document specifies procedures for validation of high-speed tensile test data. It specifies a method to determine the spectrum of the natural oscillation frequencies of the force transducer and grip configuration of the high-speed tensile test equipment. The lowest significant frequency is used for the validation. This validation procedure only applies to force measurement systems used in high-speed tensile testing machines showing a level of resonance influence that could be critical to the obtained result. Once the relevant frequencies of the system and the anticipated strain for the given material are known, this method allows to calculate the theoretical maximum allowed test speed too.
Plastiques — Validation des courbes force-temps obtenues à partir d'essais de traction à grande vitesse
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INTERNATIONAL ISO
STANDARD 22183
First edition
2023-05
Plastics — Validation of force-time
curves obtained from high-speed
tensile tests
Plastiques — Validation des courbes force-temps obtenues à partir
d'essais de traction à grande vitesse
Reference number
ISO 22183:2023(E)
© ISO 2023
---------------------- Page: 1 ----------------------
ISO 22183:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
© ISO 2023 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 22183:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 4
5 Measurement of the natural oscillation spectrum of the grip and force transducer
configuration .5
5.1 Measurement of natural oscillation frequencies . 5
5.1.1 Set-up of the high-speed tensile equipment . 5
5.1.2 Set-up of the striker . 5
5.1.3 Measurement procedure . 5
5.2 Determination of the natural oscillation spectrum . 6
6 Validation . . 7
6.1 Minimum event time . 7
6.2 Maximum allowed intensity . 8
7 Test report . 9
Annex A (informative) Configuration of the high-speed testing machine .11
Annex B (informative) Example for the measurement of natural oscillation frequencies .15
Annex C (informative) Influence of a set position on the natural oscillation spectrum .18
Annex D (informative) Relation between the nominal test speed and the nominal strain .21
Bibliography .23
iii
© ISO 2023 – All rights reserved
---------------------- Page: 3 ----------------------
ISO 22183:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had received notice of
(a) patent(s) which may be required to implement this document. However, implementers are cautioned
that this may not represent the latest information, which may be obtained from the patent database
available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent
rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2,
Mechanical properties.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
© ISO 2023 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 22183:2023(E)
Introduction
The method described in this document provides criteria for the validation of measurement curves
obtained from high-speed tensile tests.
Force, time, travel and strain measurement systems of high-speed tensile equipment are usually
calibrated in static mode. Dynamic effects, occurring at such tests, need to be addressed and limits or
ranges of use for the obtained assessment parameters need to be set in order to allow the validation of
the obtained measurement curves.
This document contains a method to measure the spectrum of the natural mechanical frequencies of
the force transducer and grip arrangement, considering that these frequencies are the most important
limiting factor for the range of use of a high-speed tensile test equipment.
In addition, there are further parameters which may play a role for the dynamic quality of the
measurement curves, such as the data acquisition frequency, or oscillations generated in the machine
frame. These parameters should be carefully supervised, and measures need to be taken if such
problems occur in a significant way.
In case direct travel or strain measurement is used to generate stress-strain curves or to determine
nominal or local strain rates, further parameters, such as the synchronization between force, time and
strain channels, need to be supervised.
v
© ISO 2023 – All rights reserved
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 22183:2023(E)
Plastics — Validation of force-time curves obtained from
high-speed tensile tests
1 Scope
This document specifies procedures for validation of high-speed tensile test data. It specifies a method
to determine the spectrum of the natural oscillation frequencies of the force transducer and grip
configuration of the high-speed tensile test equipment.
The lowest significant frequency is used for the validation. This validation procedure only applies to
force measurement systems used in high-speed tensile testing machines showing a level of resonance
influence that could be critical to the obtained result. Once the relevant frequencies of the system and
the anticipated strain for the given material are known, this method allows to calculate the theoretical
maximum allowed test speed too.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
unloaded region
time domain prior to the application of the load by the striker
Note 1 to entry: See Figure 1.
3.2
striking peak
first force peak generated by the striker hitting the grip
Note 1 to entry: See Figure 1.
3.3
residual oscillations region
oscillations triggered by the striker
Note 1 to entry: It represents the force on the time domain after the strike of the striker.
Note 2 to entry: See Figure 1.
1
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---------------------- Page: 6 ----------------------
ISO 22183:2023(E)
Key
X time (ms)
Y force (N)
1 unloaded region
2 striking peak
3 residual oscillations region
Figure 1 — Typical force-time signal during the impact test
3.4
maximum force within the residual oscillations
F
r,max
maximum force – intended as absolute value – present in the residual oscillations, excluding the striking
peak
Note 1 to entry: It is expressed in Newtons (N).
3.5
maximum force in the unloaded state
F
u,max
maximum absolute force value in the unloaded region
Note 1 to entry: It is expressed in Newtons (N).
3.6
natural oscillation spectrum
frequency spectrum obtained as a result of a Fast Fourier Transform Analysis of the residual oscillations
region, normalized to the largest amplitude present
3.7
frequency
f
frequency of a relevant peak in the natural frequency spectrum
Note 1 to entry: It is expressed in kilohertz (kHz).
3.8
normalized intensity of the frequency
I
normalized intensity of frequency peak in the natural oscillation spectrum
2
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ISO 22183:2023(E)
3.9
lowest relevant frequency
f
low
frequency of the first relevant peak in the natural oscillation spectrum
Note 1 to entry: It is expressed in kilohertz (kHz).
3.10
event time
t
e
time from the start point of the force-time curve without unloaded region to the point of the relevant
event to be measured
Note 1 to entry: The relevant event is either the yield point, or the break point or any other defined point.
Note 2 to entry: It is expressed in milliseconds (ms).
3.11
threshold number of waves in the event
w
N,th
minimum number of waves of the relevant lowest frequency within the event time
3.12
gripping distance
L
initial length of the part of the specimen between the grips
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Annex A.
3.13
grip displacement
ΔL
displacement of the grip pulled to tensile direction of specimens from the beginning of the test
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: Most of the loading mechanics of the high-speed tensile test device have the one side pulled and
the other end fixed, as shown in Annex A.
3.14
nominal strain
ε
t
grip displacement divided by the initial gripping distance
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
3.15
nominal test speed
v
rate of separation of the gripping jaws
Note 1 to entry: It is expressed in metres per second (m/s).
3.16
maximum force
F
max
maximum force observed in the whole force-time curve during the high-speed tensile test
Note 1 to entry: See Figure 2.
3
© ISO 2023 – All rights reserved
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ISO 22183:2023(E)
Note 2 to entry: It is expressed in Newtons (N).
3.17
maximum amplitude of oscillations
ΔF
a,max
largest peak-to-peak amplitude of oscillations, observed over a small portion of the curve during the
high-speed tensile test, ignoring single spikes of electronic noise
Note 1 to entry: See Figure 2.
Note 2 to entry: It is expressed in Newtons (N).
Key
X
time (ms )
Y force (N)
1 event time (ms)
t
e
2 maximum force (N)
F
max
3 maximum amplitude of oscillations (N)
ΔF
am, ax
Figure 2 — Typical force-time curve during tensile test at high speed
4 Principle
The principle of this document is based on the following two acceptance criteria:
1) The measurement of the natural oscillations of grip and force transducer configuration (see 6.1)
The natural oscillation frequencies of the force transducer and grip arrangement in the testing
instrument are measured after a defined impact. These frequencies are analysed by means of a Fast
Fourier Transform (FFT) and presented by their intensity over the relevant frequency range. The
highest intensity observed is used to calculate a normalized intensity. The lowest frequency of a
relevant normalized intensity will be used to establish the validation criterion.
2) The maximum allowed intensity (see 6.2)
The intensity of oscillations superimposed on the force – time curve is calculated by the ratio between
the oscillation amplitude and the maximum force observed during the test.
4
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ISO 22183:2023(E)
5 Measurement of the natural oscillation spectrum of the grip and force
transducer configuration
5.1 Measurement of natural oscillation frequencies
5.1.1 Set-up of the high-speed tensile equipment
The force transducer and the grip shall be well tightened and installed according to the equipment
manufacturer’s advice. If the jaw faces of the grips cannot be tightened without clamping a test
specimen, as it may be the case when using wedge-type grips, use a small part of a rigid test specimen
to ensure the jaw faces to be in a fixed and tightened situation.
5.1.2 Set-up of the striker
Use the striker capable of creating a defined single centric impact to the grip in the direction of the
machine axis. It is recommended to use a tool that allows variation of the impact intensity and to adjust
the striking position.
NOTE 1 A typical device of the striker and its striking position is shown in Annex B.
The mass and the impact speed of the striker shall be such to ensure that the maximum force within the
residual oscillations F is higher than 10 % of the full-scale value of the selected force measurement
rm, ax
range and greater than 200 N.
NOTE 2 Preliminary tests to achieve these conditions are detailed in 5.1.3.
The impact force shall not exceed the capacity of the force transducer.
The direction of stroke shall coincide with the machine axis and be centric to it to within ±5 mm.
If it is not possible to create a centric impact due to the design of the grip, perform the impact at the
closest possible position providing the least lateral oscillations and report the striking position with
the results.
NOTE 3 Influence of the striking position on the natural oscillation spectrum is shown in Annex C.
5.1.3 Measurement procedure
Carry out preliminary impacts to adjust the impact speed of the striker in a way to ensure that the
maximum force within the residual oscillations F :
rm, ax
— is higher than 10 % of the full-scale value of the selected force measurement range;
— is at least 200 N;
— is at least 3 times higher than the maximum force in the unloaded state F .
um, ax
Adjust the zero-point of the force measurement system.
Adjust the sampling rate in such way to be at least twice the natural oscillation frequency to be analysed.
A minimum sampling rate of 100 kHz is recommended.
Select the suitable range of the amplifier.
Measure the force resulting from the natural frequency oscillation over a time between 5 ms and 12 ms,
in order to have enough measurement points for the FFT evaluation.
Perform three measurement strikes in accordance with the defined conditions and record the force-
time data in the unloaded state and after the impact for each impact.
Note the amplifier range, the cut-off frequency and the data acquisition frequency being used.
5
© ISO 2023 – All rights reserved
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ISO 22183:2023(E)
Determine F and F , and ensure that the required relationship is achieved.
rm, ax um, ax
5.2 Determination of the natural oscillation spectrum
Use FFT to acquire the amplitude spectrum from the force-time curve acquired from the impact test.
Determine the length of the time-window to be used in the calculations of FFT.
In the case of acquiring the amplitude spectrum, data from 1,5 cycles after the force peak during impact
test shall be used.
Select the appropriate window function and record the window function used.
Compare the frequency spectra obtained from the three measurements and check if the peaks occur
at about the same frequencies and with similar intensities. If not, check for any loose parts and for the
correct introduction of the impact strike and repeat the measurement.
The natural oscillation spectrum shall be plotted as the normalized intensity of the amplitude spectrum
as a function of the frequency (see Figure 3). The spectrum to be reported is an average value, obtained
from the spectrum results of each impact test.
Select the lowest frequency in the natural oscillation spectrum showing a normalized intensity of 50 %
or more. This is the lowest relevant frequency f which is to be used for the validation (see Figure 3).
low
NOTE Annex B indicates example of measurements of the natural oscillation spectrum of a testing machine.
Key
X frequency (kHz)
Y normalized intensity (%)
1 normalized intensity of 50 %
2
lowest relevant frequency ( f ), expressed in kilohertz (kHz)
low
Figure 3 — Typical natural oscillation spectrum of the impact test
6
...
DRAFT INTERNATIONAL STANDARD
ISO/DIS 22183
ISO/TC 61/SC 2 Secretariat: SAC
Voting begins on: Voting terminates on:
2022-06-21 2022-09-13
Plastics — Validation of force-time curves obtained from
high- speed tensile tests
ICS: 83.080.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 22183:2022(E)
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. © ISO 2022
---------------------- Page: 1 ----------------------
ISO/DIS 22183:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
© ISO 2022 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 22183:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 4
5 Measurement of the natural oscillation spectrum of the grip and force transducer
configuration .5
5.1 Measurement of natural oscillation frequencies . 5
5.1.1 Set-up of the high-speed tensile equipment . 5
5.1.2 Set-up of the striker . 5
5.1.3 Measurement procedure . 5
5.2 Determination of the natural oscillation spectrum . 6
6 Validation . . 7
6.1 Minimum event time . 7
6.2 Maximum allowed intensity . 9
7 Test report .10
Annex A (informative) Configuration of the high-speed testing machine .12
Annex B (informative) Example for the measurement of natural oscillation frequencies .16
Annex C (informative) Influence of a set position on the natural oscillation spectrum .19
Annex D (informative) Relation between the nominal test speed and the nominal strain .22
Bibliography .24
iii
© ISO 2022 – All rights reserved
---------------------- Page: 3 ----------------------
ISO/DIS 22183:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be Noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2,
Mechanical properties.
This is the first edition of ISO 22183.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
© ISO 2022 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/DIS 22183:2022(E)
Introduction
The method described by this ISO standard provides criteria for the validation of measurement curves
obtained from high-speed tensile tests.
Force, time, travel and strain measurement systems of high-speed tensile equipment is usually
calibrated in static mode. Dynamic effects, occurring at such tests, need to be addressed and limits or
ranges of use for the obtained assessment parameters need to be set in order to allow the validation of
the obtained measurement curves.
This standard contains a method to measure the spectrum of the natural mechanical frequencies of
the force transducer and grip arrangement, considering that these frequencies are the most important
limiting factor for the range of use of a high-speed tensile test equipment.
Besides, there are further parameters which may play a role for the dynamic quality of the measurement
curves, such as the data acquisition frequency, or oscillations generated in the machine frame. These
parameters should be carefully supervised and measures need to be taken if such problems occur in a
significant way.
In case direct travel or strain measurement is used to generate stress-strain curves or to determine
nominal or local strain rates, further parameters, such as the synchronization between force, time and
strain channels, need to be supervised.
The International Organization for Standardization (ISO) draws attention to the fact that it is claimed
that compliance with this document may involve the use of a patent.
ISO takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured ISO that he/she is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In
this respect, the statement of the holder of this patent right is registered with ISO. Information may be
obtained from the patent database available at www.iso.org/patents.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those in the patent database. ISO shall not be held responsible for identifying
any or all such patent rights.
v
© ISO 2022 – All rights reserved
---------------------- Page: 5 ----------------------
DRAFT INTERNATIONAL STANDARD ISO/DIS 22183:2022(E)
Plastics — Validation of force-time curves obtained from
high- speed tensile tests
1 Scope
This document specifies procedures for validation of high-speed tensile test data. This document
specifies a method to determine the spectrum of the natural oscillation frequencies of the force
transducer and grip configuration of the high-speed tensile test equipment. The lowest significant
frequency is used for the validation. This validation procedure only applies to force measurement
systems used in high-speed tensile testing machines showing a level of resonance influence that could
be critical to the obtained result. Once the relevant frequencies of the system and the anticipated strain
for the given material are known, this method allows to calculate the theoretical maximum allowed
test velocity too.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
unloaded region
time domain prior to the application of the load by the striker
Note 1 to entry: See Figure 1.
3.2
striking peak
first force peak generated by the striker hitting the grip
Note 1 to entry: See Figure 1.
3.3
residual oscillation
oscillations triggered by the striker. It represents the force on the time domain after the strike of the
striker
Note 1 to entry: See Figure 1.
1
© ISO 2022 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/DIS 22183:2022(E)
Key
X
time (ms )
Y force (N)
1 unloaded region
2 striking peak
3 region of residual oscillation
Figure 1 — Typical force-time signal during the impact test
3.4
maximum force within the residual oscillations
F
rm, ax
maximum force – intended as absolute value – present in the residual oscillations, excluding the striking
peak
Note 1 to entry: It is expressed in Newtons (N).
3.5
maximum force in the unloaded state
F
um, ax
maximum absolute force value in the unloaded region
Note 1 to entry: It is expressed in Newtons (N).
3.6
natural oscillation spectrum
frequency spectrum obtained as a result of a Fast Fourier Transform Analysis of the residual oscillation,
normalized to the largest amplitude present
3.7
frequency
f
frequency of a relevant peak in the natural frequency spectrum
Note 1 to entry: It is expressed in kilohertz (kHz).
2
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ISO/DIS 22183:2022(E)
3.8
normalized intensity of the frequency
I
normalized intensity of frequency peak in the natural oscillation spectrum
3.9
lowest relevant frequency
f
low
frequency of the first relevant peak in the natural oscillation spectrum
Note 1 to entry: It is expressed in kilohertz (kHz).
3.10
event time
t
e
time from the start point of the force-time curve to the point of the relevant event to be measured.
Note 1 to entry: The relevant event is either the yield point, or the break point or any other defined point.
Note 2 to entry: It is expressed in milliseconds (ms).
3.11
threshold number of waves in the event
w
Nt, h
minimum number of waves of the relevant lowest frequency within the event time.
3.12
gripping distance
L
initial length of the part of the specimen between the grips
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Annex A.
3.13
grip displacement
ΔL
displacement of the grip pulled to tensile direction of specimens from the beginning of the test
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: Most of the loading mechanics of the high-speed tensile test device have the one side pulled and
the other end fixed, as shown in Annex A.
3.14
nominal strain
ε
t
grip displacement divided by the initial gripping distance
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
3.15
nominal test speed
v
rate of separation of the gripping jaws
Note 1 to entry: It is expressed in meters per second (m/s).
3
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---------------------- Page: 8 ----------------------
ISO/DIS 22183:2022(E)
3.16
maximum force
F
max
maximum force observed in the whole force-time curve during the whole high-speed tensile test
Note 1 to entry: See Figure 2.
Note 2 to entry: It is expressed in Newtons (N).
3.17
maximum amplitude of oscillations
ΔF
am, ax
largest peak-to-peak amplitude of oscillations, observed over a small portion of the curve during the
high-speed tensile test, ignoring single spikes of electronic noise
Note 1 to entry: See Figure 2.
Note 2 to entry: It is expressed in Newtons (N).
Key
X
time (ms )
Y force (N)
1 the maximum force (N)
F
max
2 the maximum amplitude of oscillation (N)
ΔF�
am, ax
3
the event time (ms )
t�
e
Figure 2 — Typical force-time curve during tensile test at high speed
4 Principle
The principle of this standard is based on the following two acceptance criteria:
1) The measurement of the natural oscillations of grip and force transducer configuration (see
clause 6.1).
4
© ISO 2022 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/DIS 22183:2022(E)
The natural oscillation frequencies of the force transducer and grip arrangement in the testing
instrument are measured after a defined impact. These frequencies are analysed by means of a Fast
Fourier Transform (FFT) and presented by their intensity over the relevant frequency range. The
highest intensity observed is used to calculate a normalized intensity. The lowest frequency of a
relevant normalized intensity will be used to establish the validation criterion.
2) The maximum allowed intensity (see clause 6.2)
The intensity of oscillations superimposed on the force – time curve is calculated by the ratio between
the oscillation amplitude and the maximum force observed during the test.
5 Measurement of the natural oscillation spectrum of the grip and force
transducer configuration
5.1 Measurement of natural oscillation frequencies
5.1.1 Set-up of the high-speed tensile equipment
The force transducer and the grip shall be well tightened and installed according to the equipment
manufacturer’s advice. If the jaw faces of the grips cannot be tightened without clamping a test
specimen, as it may be the case when using wedge-type grips, use a small part of a rigid test specimen
to ensure the jaw faces to be in a fixed and tightened situation.
5.1.2 Set-up of the striker
Use the striker capable of creating a defined single centric impact to the grip in the direction of the
machine axis. It is recommended to use a tool that allows variation of the impact intensity and to adjust
the striking position.
NOTE 1 A typical device of the striker and its striking position is shown in Annex B.
The mass and the impact speed of the striker shall be such to ensure that the maximum force within the
residual oscillations F is higher than 10 % of the full-scale value of the selected force measurement
rm, ax
range and greater than 200 N.
NOTE 2 Preliminary tests to achieve these conditions are detailed in subclause 5.1.3.
The impact force shall not exceed the capacity of the force transducer.
The direction of stroke shall coincide with the machine axis and be centric to it to within ±5 mm.
If it is not possible to create a centric impact due to the design of the grip, perform the impact at the
closest possible position providing the least lateral oscillations and report the striking position with
the results.
NOTE 3 Influence of the striking position on the natural oscillation spectrum is shown in Annex C.
5.1.3 Measurement procedure
Carry out preliminary impacts to adjust the impact speed of the striker in a way to ensure that the
maximum force within the residual oscillations F
rm, ax
— is higher than 10 % of the full-scale value of the selected force measurement range;
— is at least 200 N;
— is at least 3 times higher than the maximum force in the unloaded state F .
um, ax
Adjust the zero-point of the force measurement system.
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ISO/DIS 22183:2022(E)
Adjust the sampling rate in such way to be at least twice the natural oscillation frequency to be
analyzed. A minimum sampling rate of 100 kHz is recommended.
Select the suitable range of the amplifier.
Measure the force resulting from the natural frequency oscillation over a time between 5 ms and 12 ms,
in order to have enough measurement points for the FFT evaluation.
Perform three measurement strikes in accordance with the defined conditions and record the force-
time data in the unloaded state and after the impact for each impact.
Note the amplifier range, the cut-off frequency and the data acquisition frequency being used.
Determine F and F and ensure that the required relationship is achieved.
rm, ax rm, ax
5.2 Determination of the natural oscillation spectrum
Use FFT to acquire the amplitude spectrum from the force-time curve acquired from the impact test.
Determine the length of the time-window to be used in the calculations of FFT.
In the case of acquiring the amplitude spectrum, data from 1,5 cycles after the force peak during impact
test shall be used.
Select the appropriate window function and record the window function used.
Compare the frequency spectra obtained from the three measurements and check if the peaks occur
at about the same frequencies and with similar
...
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