EN ISO 899-1:1996
(Main)Plastics - Determination of creep behaviour - Part 1: Tensile creep (ISO 899-1:1993)
Plastics - Determination of creep behaviour - Part 1: Tensile creep (ISO 899-1:1993)
Kunststoffe - Bestimmung des Kriechverhaltens - Teil 1: Zeitstand-Zugversuch (ISO 899-1:1993)
1.1 Dieser Teil von ISO 899 legt eine Methode zur Bestimmung des Kriechverhaltens von Kunststoffen unter Zugbeanspruchung fest. Es werden Standardprobekörper unter festgelegten Bedingungen von Vorbehandlung, Temperatur und Feuchtigkeit verwendet.
Plastiques - Détermination du comportement au fluage - Partie 1: Fluage en traction (ISO 899-1:1993)
Polimerni materiali - Določanje lezenja - 1. del: Lezenje pri natezni obremenitvi (ISO 899-1:1993)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 899-1:2000
01-maj-2000
3ROLPHUQLPDWHULDOL'RORþDQMHOH]HQMDGHO /H]HQMHSULQDWH]QLREUHPHQLWYL
,62
Plastics - Determination of creep behaviour - Part 1: Tensile creep (ISO 899-1:1993)
Kunststoffe - Bestimmung des Kriechverhaltens - Teil 1: Zeitstand-Zugversuch (ISO 899-
1:1993)
Plastiques - Détermination du comportement au fluage - Partie 1: Fluage en traction (ISO
899-1:1993)
Ta slovenski standard je istoveten z: EN ISO 899-1:1996
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 899-1:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 899-1:2000
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SIST EN ISO 899-1:2000
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SIST EN ISO 899-1:2000
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SIST EN ISO 899-1:2000
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SIST EN ISO 899-1:2000
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SIST EN ISO 899-1:2000
ISO
INTERNATIONAL
8994
STANDARD
First edition
1993-12-15
- Determination of creep
Plastics
behaviour -
Part 1:
Tensile creep
Plas tiques - Determination du comportement au fluage -
Partie 1: Fluage en traction
Reference number
ISO 899-1 :1993(E)
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SIST EN ISO 899-1:2000
ISO 899=1:1993(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. Esch 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 patt in the work. ISO
collaborates closely with the International Electrotechnical Commission
(1 EC) 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 899-1 was prepared by Technical Committee
lSO/TC 61, Plastics, Sub-Committee SC 2, Mechanical properties.
Together with ISO 899-2, it cancels and replaces ISO 899:1981 and
ISO 6602:1985, which have been technically revised.
ISO 899 consists of the following Parts, under the general title
- Determination of creep behaviour:
Plas tics
- Part 1: Tensile creep
- Part 2: Flexural creep b y three-Point loading
Annexes A and B of this patt of ISO 899 are for information only.
0 ISO 1993
All rights reserved. NO part of this publication may be reproduced or utilized in any form or
by any means, electronie or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1 211 Geneve 20 l Switzerland
Printed in Switzerland
ii
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SIST EN ISO 899-1:2000
ISO 899=1:1993(E)
INTERNATIONAL STANDARD
Plastics - Determination of creep behaviour -
Part 1:
Tensile creep
possibility of applying the most recent editions of the
1 Scope
Standards indicated below. Members of IEC and ISO
maintain registers of currently valid International
1.1 This part of ISO 899 specifies a method for de-
Standards.
termining the tensile creep of plastics in the form of
Standard test specimens under specified conditions
- Standard atmospheres for
ISO 291: 1977, Plastics
such as those of pretreatment, temperature and hu-
conditioning and testing.
midity.
ISO 472:1988, Plastics - Vocabulary.
1.2 The method is suitable for use with rigid and
ISO 527-1:1993, Plastics - Determination of tensile
semi-rigid non-reinforced, filled and fibre-reinforced
properties - Part 1: General principles.
plastics materials (see ISO 472 for definitions) in the
form of dumb-hell-shaped test specimens moulded
ISO 527-2:1993, Plastics - Determination of tensile
directly or machined from sheets or moulded articles.
properties - Part 2: Test conditions for moulding and
extrusion plas tics.
1.3 The method is intended to provide data for
engineering-design and research and development
purposes.
3 Definitions
1.4 Tensile creep may vary significantly with differ-
For the purposes of this patt of ISO 899, the defi-
ences in specimen preparation and dimensions and in
nitions given in ISO 472 and the following definitions
the test environment. The thermal history of the test
aPPlY l
specimen tan also have profound effects on its creep
behaviour (see annex A). Consequently, when precise
3.1 creep: The increase in strain with time when a
comparative results are required, these factors must
constant forte is applied.
be carefully controlled.
3.2 initial stress, 0: The tensile forte per unit area
1.5 If tensile-creep properties are to be used for
of the initial Cross-section within the gauge length.
engineering-design purposes, the plastics materials
lt is given by the equation
should be tested over a broad range of Stresses,
times and environmental conditions.
F
o=-
A
2 Normative references
where
The following Standards contain provisions which,
F is the forte, in newtons;
through reference in this text, constitute provisions
of this part of ISO 899. At the time of publication, the
A is the initial Cross-sectional area of the
editions indicated were valid. All Standards are subject
specimen, in Square millimetres.
to revision, and Parties to agreements based on this
The stress is expressed in megapascals.
part of OS0 899 are encouraged to investigate the
1
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SIST EN ISO 899-1:2000
ISO 899=1:1993(E)
Stresses in the loaded section of the specimen may
3.3 extension, (hL),: The increase in the distance
be assumed to be uniformly distributed over cross-
between the gauge marks, expressed in millimetres,
sections perpendicular to the direction of the applied
at time t.
load.
It is given by the equation
NOTE 1 It is recommended that grips be used that will
W),=L,--L,
allow the specimen to be fixed in place, correctly aligned,
Prior to applying the load. Self-locking grips which allow the
where
specimen to move as the load increases are not suitable for
this test.
Lt is the gauge length, in millimetres, at any
given time t during the test;
4.2 Loading System, capable of ensuring that the
L. is the original gauge length, in millimetres,
load is applied smoothly, without causing transient
of the specimen after application of a preload
overloading, and that the load is maintained to within
but Prior to application of the test load.
+ 1 % of the desired load. In creep-to-rupture tests,
provision shall be made to prevent any shocks which
3.4 tensile-creep strain, Er: The Change in length
occur at the moment of rupture being transmitted to
per unit original length of the gauge length produced
adjacent loading Systems. The loading mechanism
by the applied load at any given time during a creep
shall allow rapid, smooth and reproducible loading.
test. lt is expressed as a dimensionless ratio or as a
percentage.
4.3 Extension-measuring device, comprising any
lt is given by the equation
contactless or contact device capable of measuring
the extension of the specimen gauge length under
W),
=-
load without influencing the specimen behaviour by
Et
L,
mechanical effects (e.g. undesirable deformations,
notches), other physical effects (e.g. heating of the
specimen) or Chemical effects. In the case of
contactless (Optical) measurement of the strain, the
W),
=-x 100 (%)
Et
longitudinal axis of the specimen shall be perpen-
LO
dicular to the Optical axis of the measuring device. The
accuracy of the extension-measuring device shall be
3.5 tensile-creep modulus, E,: The ratio of initial
within + 0,Ol mm.
-
stress to creep strain, calculated as in 7.1.
For creep-to-rupture tests, it is recommended that the
3.6 isochronous stress-strain curve: A Cartesian extension be measured by means of a contactless
Optical System operating on the cathetometer prin-
plot of stress versus creep strain, at a specific time
ciple. Automatic indication of time to rupture is highly
after application of the test load.
desirable. The gauge length shall be marked on the
either by attaching (metal) Clips with
specimen,
3.7 time to rupture: The period of time which
scratched-on gauge marks, or by gauge marks ruled
elapses between the Point in time at which the
with an inert, thermally stable paint.
specimen is fully loaded and the rupture Point.
Electrical-resistance strain gauges are suitable only if
3.8 creep-strength limit: That initial stress which
the material tested is of such a nature as to permit
will just Cause rupture (0s J or will produce a specified
such strain gauges to be attached to the specimen
strain (a,,J at a specified ti’me t, at a given temperature
by means of adhesive and only if the adhesion quality
and relative humidity.
is constant during the duration of the test.
3.9 recovery from creep: The decrease in strain at
any given time after completely unloading the speci-
44 . Time-measurement device, accurate to 0,l %.
men, expressed as a percentage of the strain just
Prior to the removal of the load.
4.5 Micrometer, reading to 0,Ol mm or closer, for
measuring the thickness and width of the test speci-
men.
4 Apparatus
4.1 Gripping device, capable of ensuring that the 5 Test specimens
direction of the load applied to the test specimen co-
incides as closely as possible with the longitudinal Use test specimens of the Same shape and dimen-
axis of the specimen. This ensures that the test sions as specified for the determination of tensile
specimen is subjected to simple stress and that the properties (see ISO 527-2).
2
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SIST EN ISO 899-1:2000
ISO 899=1:1993(E)
6.5.2 Loading
6 Procedure
Load the test specimen progressively so that fuli
loading of the test specimen is reached between 1 s
Conditioning and test atmosphere
6.1
and 5 s after the beginning of the application of the
load. Use the same rate of loading for each of a series
Condition the test specimens as specified in the ln-
of tests on one material.
ternational Standard for the material under test. In the
absence of any information on conditioning, use the
Take the total load (including the preload) to be the
most appropriate set of conditions specified in
test load.
ISO 291, unless otherwise agreed upon by the inter-
ested Parties.
6.6 Extension-measurement schedule
NOTE 2 The creep behaviour will be affected not only by
the thermal history of the specimen under test, but also by
Record the Point in time at which the specimen is
the temperature and (where applicable) humidity used in
fully loaded as t = 0. Unless the extension is auto-
conditioning.
matically and/or continuously recorded, choose the
times for making individual measurements as a func-
Conduct the test in the same atmosphere as used for
tion of the creep curve obtained from the particular
conditioning, unless otherwise agreed upon by the
material under test. lt is preferable to use the follow-
interested Parties, e.g. for testing at elevated or low
ing measurement schedule:
temperatures. Ensure that the Variation in tempera-
ture during the duration of the test remains within
1 min, 3 min, 6 min, 12 min and 30 min;
+ 2 “C.
-
1 h, 2 h, 5 h, 10 h, 20 h, 50 h, 100 h, 200 h,
500 h, 1 000 h, etc.
6.2 Measurement sf test-specimen
dimensions
If discontinuities are suspected or encountered in the
creep-strain versus time Plot, take readings more fre-
Measure the dimensions of the conditioned test
quently than recommended above.
specimens in accordance with ISO 527-1 :1993, sub-
clause 9.2.
6.7 Time measurement
Measure, to within + 0,l % or + 2 s (whichever is the
6.3
...
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