ISO/DIS 10813-1

Vibration-generating machines -- Guidance for selection

Générateurs de vibrations -- Lignes directrices pour la sélection

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD ISO/DIS 10813-1
ISO/TC 108/SC 6 Secretariat: GOST R
Voting begins on Voting terminates on
2002-06-06 2002-11-06

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION

Vibration-generating machines — Guidance for selection —
Part 1:
Equipment for environmental testing
Générateurs de vibrations — Lignes directrices pour la sélection —
Partie 1: Moyens pour les essais environnementaux
ICS 17.160

In accordance with the provisions of Council Resolution 15/1993 this document is circulated

in the English language only.

Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est

distribué en version anglaise seulement.

To expedite distribution, this document is circulated as received from the committee

secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at

publication stage.

Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du

secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au

Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY 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 NATIONAL REGULATIONS.
© International Organization for Standardization, 2002
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ISO/DIS 10813-1
Copyright notice

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ISO/DIS 10813-1
Contents Page

Foreword.....................................................................................................................................................................iv

Introduction .................................................................................................................................................................v

1 Scope..............................................................................................................................................................1

2 Normative references....................................................................................................................................1

3 Terms and definitions....................................................................................................................................1

4 Requirements for vibration tests..................................................................................................................2

4.1 Vibration test purposes.................................................................................................................................2

4.2 Test methods..................................................................................................................................................2

5 Types and characteristics of vibration generators ....................................................................................4

5.1 Main types of vibration generators ..............................................................................................................4

5.2 Major parameters...........................................................................................................................................4

5.3 Features..........................................................................................................................................................5

5.4 Comparison between electrodynamic, servohydraulic and mechanical vibration generators ...........12

6 Recommendation for the selection of vibration generator .....................................................................14

6.1 Selection of the type....................................................................................................................................14

6.2 Selection of the model.................................................................................................................................14

6.3 Selection of components ............................................................................................................................18

Annex A (informative) Examples..............................................................................................................................24

Annex B (informative) Vibration severity in test methods standardised by IEC.................................................27

Bibliography ..............................................................................................................................................................30

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ISO/DIS 10813-1
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 3.

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.

ISO 10813-1 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock, Subcommittee

SC 6, Vibration and shock generating systems.

ISO 10813 consists of the following parts, under the general title Vibration generating machines — Guidance for

selection:
 Part 1: Equipment for environmental testing
 Part 2: Equipment for dynamic structural testing
Annexes A and B are for information only.
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ISO/DIS 10813-1
Introduction

To select a suitable vibration generating system is an urgent problem as one needs to purchase new test

equipment or to update the equipment being already at one's disposal for purposes of a certain test or to choose

the equipment among proposed by a test laboratory or even a laboratory itself which offers its service to carry out

such a test. A problem like this can be resolved quite correctly if only a number of factors are considered

simultaneously, as follows:

 type of the test to be carried out (environmental testing, normal and/or accelerated, dynamic structural testing,

diagnosis, calibration, etc.);
 requirements followed from the test requirements;

 test conditions (one mode of vibration or combined vibration, single vibration test or combined test, for example,

dynamic plus climatic, etc.);
 objects to be tested.

This part of ISO 10813 deals only with equipment to be used during environmental testing, and procedures of the

selection are predominantly to meet the requirements of this testing. However the user should keep in mind that

specific test condition and specific object to be tested can significantly influence the selection. Thus, to excite a

specimen inside a climatic chamber imposes limitations on vibration generator interface, and a specimen of a big

size and/or of a complex shape, having numerous resonances in all directions, demands larger equipment than one

followed from the procedures of this part of ISO 10813 assuming that excitation is to be applied to the rigid body of

the same mass. Unfortunately, such aspects can hardly be formalised and, thus, are not covered by this part of ISO

10813.

If the equipment is expected to be used for test of different types, all possible applications should be accounted

when selecting. Thus, if the vibration generator is acquired to be applied during both environmental and dynamic

structural testing, Parts 1 and 21) of ISO 10813 should be used simultaneously. It is presumed in this part of ISO

10813 that the system to be selected will enable to drive the object under the test up to a specified level. In order to

generate an excitation without undesired motions, a suitable control system should be used. The selection of a

control system will be considered in a further International Standard.

It should be emphasized that vibration generating systems are complex machines, so the correct selection always

demands a certain degree of engineering judgement. As a consequence, the purchaser, when selecting the

vibration test equipment, can resort to the help of a third party. In such a case, this part of ISO 10813 can help the

purchaser to ascertain, if the solution proposed by the third party is acceptable or not. Besides, designers and

manufacturers can use this part of ISO 10813 to assess the market environment.
To be published.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 10813-1
Vibration-generating machines — Guidance for selection —
Part 1:
Equipment for environmental testing
1 Scope

This part of ISO 10813 gives guidance for the selection of vibration generating equipment used for vibration

environmental testing – dependent on the test requirements.
This guidance covers such aspects of the selection as
 selection of the equipment type (6.1);
 selection of the model (6.2);
 selection of some critical components (6.3), excluding the control system.
Some examples of the selection are given in annex A.
2 Normative references

The following normative documents contain provisions, which through reference in this text constitute provisions of

this part of ISO 10813. For dated references, subsequent amendments to, or revisions of, any of these publications

do not apply. However, parties to agreements based on this part of ISO 10813 are encouraged to investigate the

possibility of applying the most recent editions of the normative documents indicated below. For undated

references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain

registers of currently valid International Standards.
ISO 2041:1990, Vibration and shock — Vocabulary.
ISO 5344:- , Electrodynamic vibration generating systems — Performance.

ISO 8626:1989, Servo-hydraulic test equipment for generating vibration — Methods of describing characteristics.

1)
ISO 15261:- , Vibration and shock generating systems — Vocabulary.
3 Terms and definitions

For the purposes of this part of ISO 10813 the terms and definitions given in ISO 2041, ISO 5344, ISO 8626 and

ISO 15261 apply.
To be published.
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ISO/DIS 10813-1
4 Requirements for vibration tests
4.1 Vibration test purposes

The purpose of vibration tests is to estimate the capability of an object to maintain its operational characteristics

and to stay intact under vibration loading of defined severity. The tests are subdivided, in accordance with their

tasks, into functional, strength and endurance tests.

Strength tests are carried out to estimate the capability of an object to withstand vibration of defined severity and to

stay in working order when excitation is removed. In these tests vibration might cause mechanical damage (fatigue)

and may be used to predict lifetime of the object under vibration.

Endurance tests are carried out to estimate the capability of an object to function and maintain the operation

parameters within the acceptable limits under vibration. Usually during those tests the object is working for a

defined period in its normal condition and is being exposed to vibration not causing mechanical damage to it. Faults

and malfunctions in the operation of the object are registered.
4.2 Test methods
4.2.1 General

Laboratory test methods may use both sinusoidal and multifrequency excitation in various forms such as sinusoidal

at a fixed frequency, swept sinusoidal, random (narrow-band or wide-band), etc., as well as in a mixed mode. The

excitation may be multidirectional and/or multipoint.
Test specifications usually deal with the following waveforms:
 sinusoidal at a fixed frequency;
 swept sinusoidal;
 wide-band random;
 time history;
 sine-beat.

In this clause, above waveforms are briefly described primarily in aspects as standardised by IEC (see [1-4]),

however the user should be aware that other variants of a waveform can be used for specific applications.

Requirements to the test excitation (and, hence, to the test equipment) as having their origin in test method

standardised by IEC are given for information in annex B.
4.2.2 Sinusoidal vibration
4.2.2.1 Sinusoidal vibration at fixed frequencies

This excitation consists of a set of discrete-frequency sinusoidal processes of defined amplitude, applied

sequentially to the tested object within the frequency range of interest. Frequency and amplitude are adjusted

manually. A control system maintains displacement or acceleration amplitude. The test conditions include the

frequency range (bands) and individual fixed frequencies, test duration and displacement, velocity or acceleration

amplitude.
4.2.2.2 Swept sinusoidal vibration

This excitation is a sinusoidal signal of a constant amplitude, commonly defined in displacement terms at the low

frequencies and in acceleration terms at the high frequencies. The frequency is continuously swept from the lower

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ISO/DIS 10813-1

to the upper limit of the frequency range of interest and vice versa. Cross-over frequency usually lies in the range of

10 Hz to 500 Hz. A control system maintains the displacement or acceleration amplitude. During the frequency

sweep, the mechanical resonances and undesirable mechanical and functional behaviour of the test object can be

observed and identified. The test conditions include the frequency range of interest, displacement and acceleration

amplitudes, cross-over frequency, sweep rate and test duration.
4.2.3 Wide-band random vibration

The wide-band random excitation, specified by the shape of spectral density of acceleration to be close to real

operation conditions in the frequency range of interest, is generated at the control point of the table/object. The test

conditions include the acceleration spectral density levels for the frequency bands in which tests are carried out.

4.2.4 Time-history method

The test consists of subjecting the specimen to a time-history specified by a response spectrum with characteristics

simulating the effects of short-duration random-type forces. A time-history may be obtained from a natural event

(natural time-history) or from a random sample or as a synthesized signal (artificial time-history). The use of a time-

history allows a single test wave to envelop a broad-band response spectrum, simultaneously exciting all modes of

the specimen with the account of the combined effects of the coupled modes.

This test is applied to specimens, which in service can be subjected to short-duration random-type dynamic forces

induced, for example, by earthquakes, explosions or transportation.

The test conditions include the frequency range of interest, required response spectrum, number and duration of

time-histories, number of high peaks of the response.
4.2.5 Sine-beat method

In this test the specimen is excited at fixed frequencies (to be experienced in the practical application or to be

changed with a step of not greater than one-half octave) with a preset number of sine beats (see Figure 1). These

fixed frequencies may be critical frequencies identified by means of vibration response investigation.

Key
1 Carrier wave (test frequency)
2 Envelope curve (modulating frequency)
Figure 1 — Typical sequence of sine beats

The test conditions include the frequency range, test level, number of cycles in the sine beat, number of sine beats.

A control system maintains the displacement amplitude below the cross-over frequency and the acceleration

amplitude above the cross-over frequency.
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ISO/DIS 10813-1
5 Types and characteristics of vibration generators
5.1 Main types of vibration generators
5.1.1 General

A vibration generator is the final control element of a vibration generating system, providing generation of desired

vibration and transmission of it to the object being tested. The type and performance of a vibration generator

determine the main system characteristics such as force generation capabilities, permissible loads,

displacement/velocity/acceleration amplitudes, frequency ranges and accuracy characteristics (tolerances,

distortions, transverse motions, etc.). Depending on their design, vibration generators are subdivided into

electrodynamic, servohydraulic, mechanical, electromagnetic, piezoelectric, magnetostrictive, etc. The most

common types of vibration generators being used for environmental testing are electrodynamic, servohydraulic and

mechanical.
5.1.2 Electrodynamic vibration generator

This type of vibration generators produces a vibration force by interaction of a static magnetic field and an

alternating magnetic fields. The alternating magnetic field is produced by an alternating current in the moving coil

which is an actuator.

A vibration generating system including an electrodynamic vibration generator is called an electrodynamic system.

It consists of power amplifier, input signal source and control system, measuring instrumentation, field power

supply, and auxiliaries. The system may also include an auxiliary table.
5.1.3 Servohydraulic vibration generator

This type of vibration generators produces a vibration force by application of a liquid pressure being changed in a

predetermined manner. In servohydraulic vibration generators, force and motion are transmitted to the object by a

hydraulic actuator (piston pushed by fluid) controlled by servovalves.

A vibration generating system including a servohydraulic vibration generator is called a servohydraulic system. It

consists of hydraulic power supply system, signal source, close loop control system, measurement and auxiliary

equipment.
5.1.4 Mechanical vibration generator

This type of vibration generators produces a vibration force by transformation of mechanical rotation energy.

Mechanical vibration generators are classified into kinematic and reaction-type vibrators.

In kinematic vibrators, the tested object is moved by some control unit directly, for example by a crank, a rocker or

a cam.

In reaction-type vibrators, the centrifugal force is generated by rotational movement (sometimes by reciprocal

movement) of unbalanced masses.

A vibration generating system including a mechanical vibration generator is called a mechanical system.

5.2 Major parameters

ISO 5344 and ISO 8626 deal with characteristics of electrodynamic and servohydraulic vibration generators

respectively. They cover the following main characteristics:
 rated force;
 permissible static load;
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ISO/DIS 10813-1
 frequency range;
 limits for displacement, velocity and acceleration;
 total distortion;
 transverse motion ratio;
 uniformity of table motion;
resonance frequencies.
5.3 Features
5.3.1 Electrodynamic vibration generator

Typical parameters for electrodynamic vibration generators are given in the Table 1. Manufacturers offer various

series or steps of force ratings for the vibration generating system. When a system is being purchased from a

manufacturer, or being selected for usage from several systems of purchaser's own, it is recommended to use

actual specification sheets.
Table 1 — Typical parameters for electrodynamic vibration generators
Rated force, Output of the Frequency Maximum Maximum Maximum Maximum Mass of
N power range, Hz displacement, velocity, acceleration load, kg moving
amplifier, VA mm m/s without load, system, kg
m/s
31,5 6,3 5 to 13 000 2,5 0,4 200 1,0 0,16
63 19 5 to 10 000 2,5 0,4 300 1,5 0,2
125 62,5 5 to 8 000 5,0 0,8 500 2,0 0,25
250 165 5 to 8 000 8,0 1,3 650 4,0 0,38
500 400 5 to 7 000 8,0 1,3 800 10,0 0,62
1 000 1 000 5 to 5 000 12,5 2,0 1 000 25,0 1,0
2 000 2 000 5 to 5 000 12,5 2,0 1 000 75,0 2,0
4 000 4 000 5 to 4 000 12,5 2,0 1 000 200,0 4,0
8 000 8 000 5 to 3 500 12,5 2,0 1 000 300,0 8,0
16 000 16 000 5 to 3 000 12,5 2,0 1 000 400,0 16,0
32 000 32 000 5 to 2 500 12,5 2,0 1 000 500,0 32,0
64 000 64 000 5 to 2 000 12,5 2,0 1 000 1 000,0 64,0
128 000 128 000 5 to 1 800 12,5 2,0 1 000 2 000,0 128,0
200 000 200 000 5 to 1 600 12,5 2,0 1 000 3 125,0 200,0

NOTE Upper limits for different vibration parameters can not be achieved simultaneously

The main features of electrodynamic vibration generators are the following:

 possibility of any type of excitation: sinusoidal (at fixed frequencies and swept), random (broad-band and

narrow-band), etc.;
 ease of control (manual and automatic);
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ISO/DIS 10813-1

 wide frequency range: 0,5 Hz up to 15 000 Hz (typically 5 to 5 000 Hz), the lower the rated force the higher is

the upper limit of the frequency range;

 high displacement: up to ± 25 mm (typically up to 12,5 mm), and acceleration: up to 1 500 m/s (typically up to

1 000 m/s );
 high force: up to 400 kN (typically up to 200 kN);
 relatively large permissible load: up to 4 000 kg (typically up to 1 000 kg);

 low harmonic distortion: about 5 %, excluding frequency bands where distortion increases because of

resonances of the vibration generator and the load;

 acceptable transverse motion and uniformity of table motion: about 10 %, excluding frequency bands where an

undesired motion arises due to moving system resonances or off-set test loads;

 possibility of connecting two vibration generators (acting in push-pull mode) to one vibrating table from

opposite sides.

One disadvantage of electrodynamic generator is caused by the presence of a magnetic field in the area of the

vibration table, which, however, may be reduced to the order of 0,001T by means of special compensation

devices.

Also rated force can not be generated over the whole frequency range. It is limited by rated travel at low

frequencies, by rated voltage at middle frequencies and by resonances of the moving system at high frequencies.

Rated acceleration and displacement depend on load mass. ISO 5344 states six test loads m , m , m ,

0 1 4

m , m , m , where the first load is zero and the following are those permitting maximal accelerations of 10

10 20 40
2 2 2 2 2

m/s , 40 m/s , 100 m/s , 200 m/s and 400 m/s respectively. Figure 2 shows typical curves of acceleration

(displacement, velocity) against frequency for various loads.
2 2

In the case of random vibration rated force is defined in terms of Φ ()f , in (m/s ) /Hz (see ISO 5344):

Φ ()f = 0; f < 20 Hz
Φ ()f =()f 100 Φ ; 20 Hz < f < 100 Hz
a 0
Φ ()f = Φ ; 100 Hz < f < 2000 Hz
a 0
4 -4
Φ ()f < Φ()2000 f or 10 Φ ; f > 2000 Hz
a 0 0

The corresponding curve of acceleration spectral power density for electrodynamic vibration generator is shown in

Figure 3.
Crest factor should not be less than 3.
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Key
1 Displacement limit
2 Velocity limit
3 Maximum acceleration
Figure 2 — Typical curves for electrodynamic vibration generators
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Figure 3 — Shape of acceleration power spectral density for electrodynamic vibration generator (ISO 5344)

5.3.2 Servohydraulic vibration generator

Typical features for servohydraulic vibration generators are given in the Table 2. Manufacturers offer various series

or steps of force ratings for the vibration generating system. When a system is being purchased from a

manufacturer, or being selected to use from several systems of purchaser's own, it is recommended to use actual

specification sheets.
The main features of servohydraulic vibration generators are the following:
 possibility of any type of excitation;
 ease of control (manual and automatic);

 frequency range extended down to D.C. and limited at high frequencies by 800 Hz; (typically not exceeding

100 Hz);

 high displacement: up to 200 mm, acceleration: up to 1 000 m/s ; velocity: up to 10 m/s (typically up to 2 m/s);

 very high force: up to 10 MN (typically up to 1 MN);
 very large permissible load: up to several tonnes;
 low transverse motion: about 5 % to 10 %;
 absence of a magnetic field in the area of table;
 low sensitivity to load misalignment;

 increased harmonic distortion at the low-frequency range (below the natural frequency of the actuator): up to

15 % and more;

 low harmonic distortion at frequencies above the natural frequency: in the order of 5 %.

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Table 2 — Typical parameters for servohydraulic vibration generators
Rated force, N Frequency range, Maximum Maximum Maximum Mass of moving
Hz displacement, velocity, m/s acceleration, system, kg
mm m/s
5 000 0,1 to 140 100 2,0 1 000 5
8 000 0,1 to 100 100 2,0 1 000 8
10 000 0,1 to 100 100 2,0 1 000 10
15 000 0,1 to 100 100 2,0 1 000 15
20 000 0,1 to 100 100 2,0 1 000 20
30 000 0,1 to 60 100 2,0 1 000 30
50 000 0,1 to 60 100 2,0 1 000 50
100 000 0,1 to 60 100 1,7 600 167
200 000 0,1 to 60 100 0,8 300 667
500 000 0,1 to 30 100 0,3 100 5 000
1 000 000 0,1 to 30 100 0,1 30 33 333

Curves for servohydraulic system characteristics are presented in Figure 4. They are the same as those for

electrodynamic vibration generators excluding the sharp fall in force (acceleration) at high frequencies.

In the case of random vibration the rated values are similar to those for electrodynamic vibration generators. The

2 2

rated force is defined in terms of acceleration spectral power density Φ ()f , in (m/s ) /Hz, or displacement

spectral power density Θ()f , in m /Hz :
Φ ()f = 0; Θ()f = 0; f < f
a 1
Φ ()f = Φ ; Θ()f = Θ ; f < f < f
a 0 0 1 2
f f
2 3
2 2
f f
Φ ()f = Φ ; Θ()f = Θ ; f < f < f
a 0 0 2 3
2 2
f f
()f f
2 2
Φ ()f = Φ ; Θ()f = ; f < f < f
a 0 3 4
f ()f f f
4 4 3 2
Φ ()f = Φ ; Θ()f = Θ ; f < f < f
a 0 0 4 5
2 6
f f
2 2
()f f ()f f f f
4 5 5 4 3 2
Φ ()f = Θ()f = Θ ; f < f < f
a 0 5 6
4 8
f f
Φ ()f = 0; Θ()f = 0; f > f
a 6
where
f is the lower limit of the frequency range;

f is the cross-over frequency between constant displacement and constant velocity ranges;

f is the cross-over frequency between constant velocity and constant acceleration ranges;

f is the frequency of the first spectral power density limitation;
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f is the frequency of the second spectral power density limitation;
f is the upper limit of the frequency range.
Θ = Φ
0 0
()2πf
Key
1 Displacement limit
2 Velocity limit
3 Maximum acceleration
Figure 4 — Typical curves for servohydraulic vibration generators

The curve of acceleration spectral power density for servohydraulic vibration generator is shown in Figure 5.

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The crest factor should not be less than 3.

Figure 5 — Shape of acceleration power spectral density for servohydraulic vibration generator (ISO 8626)

5.3.3 Mechanical vibration generator
Typical parameters for mechanical vibration generators are given in Table 3.
Table 3 — Typical parameters for mechanical vibration generators

Rated load, kg Frequency range, Hz Max. displacement, Max. acceleration, Mass of moving

...