ISO 18488:2015

Polyethylene (PE) materials for piping systems — Determination of Strain Hardening Modulus in relation to slow crack growth — Test method

ISO 18488:2015 specifies a method for the determination of the strain hardening modulus which is used as a measure for the resistance to slow crack growth of polyethylene. The strain hardening modulus is obtained from stress-strain curves on compression moulded samples. This International Standard describes how such measurement is performed and how the strain hardening modulus shall be determined from such a curve. Details of the required equipment, precision, and sample preparation for the generation of meaningful data are given. ISO 18488:2015 provides a method that is valid for all types of polyethylene, independent from the manufacturing technology, comonomer, catalyst type, that are used for pipes and fittings applications. NOTE This method could be developed for materials for other applications.

Matériaux polyéthylène (PE) pour systèmes de canalisations — Détermination du module d'écrouissage en relation avec la propagation lente de fissures — Méthode d'essai

General Information

• Status: Published
• Publication Date: 19-Aug-2015
• ICS: 23.040.20 - Plastics pipes
• ICS: 23.040.45 - Plastics fittings
• Technical Committee: ISO/TC 138/SC 5 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
• Drafting Committee: ISO/TC 138/SC 5/WG 20 - Slow crack growth (SCG)

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18488
First edition
2015-09-01
Polyethylene (PE) materials for piping
systems — Determination of Strain
Hardening Modulus in relation to slow
crack growth — Test method
Matériaux polyéthylène (PE) pour systèmes de canalisations —
Détermination du module d’écrouissage en relation avec la
propagation lente de fissures — Méthode d’essai
Reference number
ISO 18488:2015(E)
©
ISO 2015

---------------------- Page: 1 ----------------------
ISO 18488:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 18488:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 3
6 Test specimens. 4
6.1 Test specimen geometry and dimensions . 4
6.2 Test specimen preparation . 4
7 Test procedure . 5
8 Data analysis . 6
9 Test report . 6
Annex A (informative) Neo-Hookean constitutive model . 8
Bibliography .10
© ISO 2015 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 18488:2015(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. I
...