ISO INTERNATIONAL STANDARD 18872 First edition 2007-02-15 Plastics Determination of tensile properties at high strain rates Plastiques Determination des proprietés en traction a hautes vitesses de déformation Reference number ISO 18872:2007(E) @ ISO 2007 ISO 18872:2007(E) PDFdisclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ?ISO2007 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, ISsO's member body in the country of the requester. ISO copyright office Case postale 56. CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ ISO 2007 -All rights reserved ISO 18872:2007(E) Contents Page Foreword iv 1 Scope 2 Normative references 3 Principle. 4 Terms and definitions 5 Apparatus 5.1 Test assembly 5.2 Extensometers 5.3 Data-recording equipment 6 Test specimens.... 6.1 Low-strainmeasurements 6.2 High-strain measurements 7 Conditioning. 8 Test procedure 8.1 General.... 8.2 Test speeds... 8.3 Recording of data 9 Calculationandexpressionofresults. 9.1 Low-strain measurements. 9.2 High-strain measurements 10 Modelling stress versus plastic strain curves. 10.1 Low-strainmeasurements.. 10.2 High-strain measurements ... 11 Determination of properties over a wide range of strain rates ... 11.1 Tensile modulus.... 11.2 Stress/plastic strain curves 6 12 Precision..... Annex A (informative) Modelling true stress against true plastic strain curves: Low-strain measurements... 8 Annex B (informative) Modelling true stress against true plastic strain curves: High-strain measurements .. @Is02007-All rights reserved ii ISO 18872:2007(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 non-governmental,inliaisonwithIsO,also take partin the work.Iso collaborates closely withthe International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 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. 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. ISO 18872 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2, Mechanical properties. iv @IsO2007-Allrightsreserved INTERNATIONAL STANDARD ISO 18872:2007(E) Plastics Determination of tensile properties at high strain rates 1 Scope This International Standard specifies procedures for determining the tensile properties of moulding and extrusion plastics over a wide range of strain rates, including high rates appropriate to impact-loading situations. Properties are determined through a combination of measurements at low and moderate strain rates, the use of mathematical functions to model these results, the rate-dependence of parameters and the measurement of properties at high rates are avoided. The measurement of properties at low and moderate strain rates is based on