ISO 844:1998
(Main)Cellular plastics — Compression test for rigid materials — Specification
Cellular plastics — Compression test for rigid materials — Specification
Plastiques alvéolaires — Essai de compression des matériaux rigides — Specification
Penjeni polimerni materiali - Tlačni preskus za trde pene - Specifikacija
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INTERNATIONAL ISO
STANDARD 844
Second edition
1998-06-01
Cellular plastics — Compression test for
rigid materials — Specification
Plastiques alvéolaires — Essai de compression des matériaux rigides —
Spécifications
A
Reference number
ISO 844:1998(E)
---------------------- Page: 1 ----------------------
ISO 844:1998(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Principle . 2
6 Apparatus . 2
7 Test specimens . 3
8 Procedure . 4
9 Expression of results . 4
Precision .
10 6
11 Test report . 6
© ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
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©
ISO ISO 844:1998(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.
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.
International Standard ISO 844 was prepared by Technical Committee
ISO/TC 61, Plastics, Subcommittee SC 10, Cellular plastics.
This second edition cancels and replaces the first edition (ISO 844:1978),
which has been technically revised.
iii
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©
INTERNATIONAL STANDARD ISO ISO 844:1998(E)
Cellular plastics — Compression test for rigid materials —
Specification
1 Scope
This International Standard specifies a method of determining
a) the compressive strength and corresponding relative deformation
or
b) the compressive stress at 10 % relative deformation
and
c) when desired, the compressive modulus
of rigid cellular plastics.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 291:1997, Plastics – Standard atmospheres for conditioning and testing.
ISO 1923:1981,Cellular plastics and rubbers – Determination of linear dimensions.
3 Terms and definitions
For the purposes of this International Standard, the following definitions apply.
3.1 relative deformation, ε: The ratio of the reduction (in relation to its initial value) in thickness of the test
specimen to its initial thickness. It is expressed as a percentage.
ε is the relative deformation corresponding to σ (see 3.2).
m m
3.2 compressive strength, σ : The maximum compressive force F divided by the initial cross-sectional area of
m m
the test specimen when the relative deformation ε is < 10 %.
3.3 compressive stress at 10 % relative deformation, σ : The ratio of the compressive force F at 10 % relative
10 10
deformation ε to the initial cross-sectional area of the test specimen.
10
1
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©
ISO 844:1998(E) ISO
3.4 compressive modulus of elasticity, E: The compressive stress divided by the corresponding relative
deformation below the proportional limit, i.e. when the relation is linear.
4 Symbols and abbreviated terms
A initial cross-sectional area, in square millimetres
0
compressive modulus of elasticity, in percent
E
F force corresponding to x (conventional proportional limit), in newtons
e e
F maximum force, in newtons
m
F force at 10 % relative deformation, in newtons
10
h initial thickness of test specimen, in millimetres
0
ε relative deformation corresponding to the compressive strength σ , in percent
m m
σ compressive strength, in kilopascals
m
σ compressive stress at 10 % relative deformation, in kilopascals
10
displacement at in the conventional elastic zone, in millimetres
x F
e e
x displacement at maximum force, in millimetres
m
x displacement at 10 % relative deformation, in millimetres
10
kPa kilopascals
Pa pascals
5 Principle
A compressive force is applied in an axial direction to the faces of a rectangular parallelepiped test specimen. The
maximum stress supported by the test specimen is calculated.
If the value of the maximum stress corresponds to a relative deformation of less than 10 %, it is noted as the
"compressive strength". Otherwise, the compressive stress at 10 % relative deformation is calculated and its value
noted as the "compressive stress at 10 % relative deformation".
6 Apparatus
6.1 Compression-testing machine
Any compression-testing machine suited to the range of force and displacement involved and having two square or
circular plane, parallel plates which are polished and cannot be deformed and of which the length of one side (or the
diameter) is at least 10 cm may be used. One of the plates shall be fixed and the other movable; the latter shall be
capable of moving at a constant rate of displacement in accordance with the conditions laid down in clause 8.
Neither plate shall be self-aligning.
2
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©
ISO ISO 844:1998(E)
6.2 Displacement- and force-measurement devices
6.2.1 Measurement of displacement
The compression-testing machine shall be fitted with a system allowing continuous measurement of the
displacement x of the movable plate with an accuracy of ±5 % or ±0,1 mm if this latter value is a more accurate
measurement (see note to 6.2.2).
6.2.2 Measurement of force
A force sensor shall be fixed to one of the machine plates in order to measure the force F produced by the reaction
of the test specimen upon the plates during the test. This sensor shall be such that its own deformation during the
course of the measurement operation is negligible compared with that being measured and, in addition, it shall allow
the continuous measurement of the force at any point in time with an accuracy of ±1 %.
NOTE – It is recommended that a device be used for the simultaneous recording of the force F and the displacement x that
allows, by plotting a curve
...
SLOVENSKI STANDARD
SIST ISO 844:2000
01-maj-2000
3HQMHQLSROLPHUQLPDWHULDOL7ODþQLSUHVNXV]DWUGHSHQH6SHFLILNDFLMD
Cellular plastics -- Compression test for rigid materials -- Specification
Plastiques alvéolaires -- Essai de compression des matériaux rigides -- Specification
Ta slovenski standard je istoveten z: ISO 844:1998
ICS:
83.100 Penjeni polimeri Cellular materials
SIST ISO 844:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST ISO 844:2000
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SIST ISO 844:2000
INTERNATIONAL ISO
STANDARD 844
Second edition
1998-06-01
Cellular plastics — Compression test for
rigid materials — Specification
Plastiques alvéolaires — Essai de compression des matériaux rigides —
Spécifications
A
Reference number
ISO 844:1998(E)
---------------------- Page: 3 ----------------------
SIST ISO 844:2000
ISO 844:1998(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Principle . 2
6 Apparatus . 2
7 Test specimens . 3
8 Procedure . 4
9 Expression of results . 4
Precision .
10 6
11 Test report . 6
© ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
---------------------- Page: 4 ----------------------
SIST ISO 844:2000
©
ISO ISO 844:1998(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.
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.
International Standard ISO 844 was prepared by Technical Committee
ISO/TC 61, Plastics, Subcommittee SC 10, Cellular plastics.
This second edition cancels and replaces the first edition (ISO 844:1978),
which has been technically revised.
iii
---------------------- Page: 5 ----------------------
SIST ISO 844:2000
---------------------- Page: 6 ----------------------
SIST ISO 844:2000
©
INTERNATIONAL STANDARD ISO ISO 844:1998(E)
Cellular plastics — Compression test for rigid materials —
Specification
1 Scope
This International Standard specifies a method of determining
a) the compressive strength and corresponding relative deformation
or
b) the compressive stress at 10 % relative deformation
and
c) when desired, the compressive modulus
of rigid cellular plastics.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 291:1997, Plastics – Standard atmospheres for conditioning and testing.
ISO 1923:1981,Cellular plastics and rubbers – Determination of linear dimensions.
3 Terms and definitions
For the purposes of this International Standard, the following definitions apply.
3.1 relative deformation, ε: The ratio of the reduction (in relation to its initial value) in thickness of the test
specimen to its initial thickness. It is expressed as a percentage.
ε is the relative deformation corresponding to σ (see 3.2).
m m
3.2 compressive strength, σ : The maximum compressive force F divided by the initial cross-sectional area of
m m
the test specimen when the relative deformation ε is < 10 %.
3.3 compressive stress at 10 % relative deformation, σ : The ratio of the compressive force F at 10 % relative
10 10
deformation ε to the initial cross-sectional area of the test specimen.
10
1
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SIST ISO 844:2000
©
ISO 844:1998(E) ISO
3.4 compressive modulus of elasticity, E: The compressive stress divided by the corresponding relative
deformation below the proportional limit, i.e. when the relation is linear.
4 Symbols and abbreviated terms
A initial cross-sectional area, in square millimetres
0
compressive modulus of elasticity, in percent
E
F force corresponding to x (conventional proportional limit), in newtons
e e
F maximum force, in newtons
m
F force at 10 % relative deformation, in newtons
10
h initial thickness of test specimen, in millimetres
0
ε relative deformation corresponding to the compressive strength σ , in percent
m m
σ compressive strength, in kilopascals
m
σ compressive stress at 10 % relative deformation, in kilopascals
10
displacement at in the conventional elastic zone, in millimetres
x F
e e
x displacement at maximum force, in millimetres
m
x displacement at 10 % relative deformation, in millimetres
10
kPa kilopascals
Pa pascals
5 Principle
A compressive force is applied in an axial direction to the faces of a rectangular parallelepiped test specimen. The
maximum stress supported by the test specimen is calculated.
If the value of the maximum stress corresponds to a relative deformation of less than 10 %, it is noted as the
"compressive strength". Otherwise, the compressive stress at 10 % relative deformation is calculated and its value
noted as the "compressive stress at 10 % relative deformation".
6 Apparatus
6.1 Compression-testing machine
Any compression-testing machine suited to the range of force and displacement involved and having two square or
circular plane, parallel plates which are polished and cannot be deformed and of which the length of one side (or the
diameter) is at least 10 cm may be used. One of the plates shall be fixed and the other movable; the latter shall be
capable of moving at a constant rate of displacement in accordance with the conditions laid down in clause 8.
Neither plate shall be self-aligning.
2
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SIST ISO 844:2000
©
ISO ISO 844:1998(E)
6.2 Displacement- and force-measurement devices
6.2.1 Measurement of displacement
The compression-testing machine shall be fitted with a system allowing continuous measurement of the
displacement x of the movable plate with an accuracy of ±5 % or ±0,1 mm if this latter value is a more accurate
measurement (see note to 6.2.2).
6.2.2 Measurement of force
A force sensor shall be fixed to one of the machine plates in order to measure th
...
NORME ISO
INTERNATIONALE 844
Deuxième édition
1998-06-01
Plastiques alvéolaires — Essai de
compression des matériaux rigides —
Spécifications
Cellular plastics — Compression test for rigid materials — Specification
A
Numéro de référence
ISO 844:1998(F)
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ISO 844:1998(F)
Sommaire Page
1 Domaine d'application . 1
2 Références normatives . 1
3 Définitions . 1
4 Symboles et abréviations . 2
Principe .
5 2
6 Appareillage . 2
7 Éprouvettes . 3
8 Mode opératoire . 4
9 Expression des résultats . 4
Fidélité .
10 6
11 Rapport d'essai . 6
© ISO 1998
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publi-
cation ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun pro-
cédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord
écrit de l'éditeur.
Organisation internationale de normalisation
Case postale 56 • CH-1211 Genève 20 • Suisse
Internet central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Imprimé en Suisse
ii
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©
ISO ISO 844:1998(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération
mondiale d'organismes nationaux de normalisation (comités membres de
l'ISO). L'élaboration des Normes internationales est en général confiée aux
comités techniques de l'ISO. Chaque comité membre intéressé par une
étude a le droit de faire partie du comité technique créé à cet effet. Les
organisations internationales, gouvernementales et non gouvernementales,
en liaison avec l'ISO participent également aux travaux. L'ISO collabore
étroitement avec la Commission électrotechnique internationale (CEI) en
ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques
sont soumis aux comités membres pour vote. Leur publication comme
Normes internationales requiert l'approbation de 75 % au moins des
comités membres votants.
La Norme internationale ISO 844 a été élaborée par le comité technique
ISO/TC 61, Plastiques, sous-comité SC 10, Plastiques alvéolaires.
Cette deuxième édition annule et remplace la première édition
(ISO 844:1978), dont elle constitue une révision technique.
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©
NORME INTERNATIONALE ISO ISO 844:1998(F)
Plastiques alvéolaires — Essai de compression des matériaux
rigides — Spécifications
1 Domaine d'application
La présente Norme internationale prescrit une méthode pour la détermination
a) de la résistance à la compression et de la déformation relative correspondante
ou
b) de la contrainte en compression à 10 % de déformation relative
et
c) lorsque cela est souhaitable, du module de compression
des matériaux alvéolaires rigides.
2 Références normatives
Les normes suivantes contiennent des dispositions qui, par suite de la référence qui en est faite, constituent des
dispositions valables pour la présente Norme internationale. Au moment de la publication, les éditions indiquées
étaient en vigueur. Toute norme est sujette à révision et les parties prenantes des accords fondés sur la présente
Norme internationale sont invitées à rechercher la possibilité d'appliquer les éditions les plus récentes des normes
indiquées ci-après. Les membres de la CEI et de l'ISO possèdent le registre des Normes internationales en vigueur
à un moment donné.
ISO 291:1977, Plastiques — Atmosphères normales de conditionnement et d'essai.
ISO 1923:1981, Plastiques et caoutchoucs alvéolaires — Détermination des dimensions linéaires.
3 Définitions
Pour les besoins de la présente Norme internationale, les définitions suivantes s'appliquent:
3.1 déformation relative, e: Rapport de la diminution d'épaisseur (par rapport à sa valeur initiale) de l'éprouvette
à son épaisseur initiale. Elle est exprimée en pourcentage.
La déformation relative correspondant à s (voir 3.2) est désignée par e .
m m
3.2 résistance à la compression, s : Rapport de la force maximale de compression F atteinte lorsque la
m m
déformation relative e est inférieure à 10 %, à l'aire initiale de la section transversale de l'éprouvette.
3.3 contrainte en compression à 10 % de déformation relative, s : Rapport de la force de compression F à
10 10
10 % de déformation relative e , à l'aire initiale de la section transversale de l'éprouvette.
10
1
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©
ISO
ISO 844:1998(F)
3.4 module d'élasticité en compression, E: Rapport de la contrainte en compression à la déformation relative
correspondante en deçà de la limite proportionnelle, c'est-à-dire quand la relation est linéaire.
4 Symboles et abréviations
aire initiale de la section transversale, en millimètres carrés, de l'éprouvette
A
0
E module d'élasticité en compression,
F force, en newtons, correspondant à x (limite proportionnelle conventionnelle)
e e
F force maximale, en newtons
m
F force, en newtons, correspondant à 10 % de déformation relative
10
h épaisseur initiale, en millimètres, de l'éprouvette
0
e déformation relative, en pourcentage, correspondant à la résistance à la compression s
m m
s résistance à la compression, en kilopascals
m
s contrainte en compression, en kilopascals, à 10 % de déformation relative
10
x déplacement, en millimètres, correspondant à F dans la zone conventionnelle d'élasticité
e e
x déplacement, en millimètres, correspondant à la force maximale
m
x déplacement, en millimètres, correspondant à 10 % de déformation relative
10
kPa kilopascal
Pa pascal
5 Principe
Une force de compression est appliquée en direction axiale sur les faces d'une éprouvette parallélépipédique
rectangle. La contrainte maximale supportée par l'éprouvette est calculée.
Si la valeur de la contrainte maximale correspond à une déformation relative inférieure à 10 %, elle est notée
comme étant la «résistance à la compression». Sinon, la contrainte en compression à 10 % de déformation relative
est calculée et sa valeur est notée comme étant la «contrainte en compression à 10 % de déformation relative».
6 Appareillage
6.1 Machine d'essai de compression
On peut utiliser toute machine d'essai de compression appropriée au domaine de force et de déplacement à mettre
en œuvre, munie de deux plateaux parallèles indéformables, de surface plane et polie, et de forme carrée ou
circulaire, dont le côté (ou le diamètre) est au moins égal à 10 cm. L'un des plateaux doit être fixe et l'autre mobile,
ce dernier devant pouvoir être animé d'une vitesse de déplacement constante, conformément aux conditions
prescrites dans l'article 8. Aucun des plateaux ne doit être à alignement automatique.
2
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©
ISO
ISO 844:1998(F)
6.2 Dispositifs de mesurage du déplacement et de la force
6.2.1 Mesurage du déplacement
La machine d'essai de compression doit être pourvue d'un système permettant le mesurage en continu du
déplacement x du plateau mobile avec une exactitude de – 5 % ou – 0,1 mm, si cette dernière valeur correspond à
une valeur de mesurage plus exacte (voir la note après 6.2.2).
6.2.2 Mesurage de la force
Un capteur de force doit être fixé à l'un des plateaux de la machine afin de mesurer la force engendrée par la
F
réaction de l'éprouvette sur les plateaux au cours de l'essai. Ce capteur doit être tel que sa propre déformation au
cours du mesurage soit négligeable en comparaison avec celle qui est à mesurer. En outre, il doit permettre le
mesurage en continu de la charge à chaque instant avec une exactitude de – 1 %.
NOTE — Il est recommandé d'utiliser un dispositif d'enregistrement simultané de la force F et du déplacement x, permettant,
par l'obtention de la courbe F = f(x), la détermination graphique des couples de valeurs F, x indiqués dans l'article 9, avec
l'exactitude exigée en 6.2.1 et dans le présent paragraphe, tout en fournissant des indicatio
...
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