ISO INTERNATIONAL STANDARD 23788 First edition 2012-07-01 Metallic materials Verification of the alignment of fatigue testing machines Materiaux metalliques Verification de I'alignement axial des machines d'essai de fatigue Reference number ISO 23788:2012(E) ISO @ISO2012 I by IHS under lic No reproduction or networking permitted without license from IHS Not for Resale ISO 23788:2012(E) COPYRiGHTPROTECTEDDOCUMENT ISO 2012 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 either ISO at the address below or ISO'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 @ ISO 2012 - All rights reserved No reproduction or networking permited withoutlicense from IHS Not for Resale ISO 23788:2012(E) Contents Page Foreword Introduction 1 Scope 2 Normative references 3 Terms and definitions. 4 Symbols 5 Measurement requirements. 5.1 Testing machine.. 5.2 Alignment cell... 5.3 Design and manufacturing .. 5.4 Machining .. 5.5 Inspection before attaching the strain gauges 5.6 Instrumentation with strain gauges 5.7 System checks. 6 Alignment measurement calculations 6.1 General 6.2 Cylindrical alignment cell. 6.3 Thick rectangular alignment cell. 9 6.4 Thin rectangular alignment cell... 9 6.5 Classification of machine alignment. 9 7 Procedure for verification of machine alignment. 10 7.1 Purpose and frequency 10 7.2 Procedure. .10 8 Reporting.. 11 8.1 Basicinformation... 11 8.2 Specialinformation 12 Annex A (informative) Causes of specimen bending and misalignment in fatigue testing machines ... 17 Annex B (normative) Evaluating uncertainty in the alignment measurement. .19 Annex C (informative) Method for measuring machine lateral stiffness .. .22 Annex D (informative) Three-strain gauge configuration . ...24 Annex E (informative) Determination of bending contribution due to inherent imperfections in a cylindrical alignment cell device. .26 Annex F (informative) Numerical example. 27 Annex G (normative) Alignment gauge - -Amethodforqualitativeassessmentofalignmentoftest systems for cylindrical specimens. 28 Bibiiography .30 ili ed without license from IHS Not for Resale