ISO INTERNATIONAL STANDARD 12107 Second edition 2012-08-15 Metallic materials Fatigue testing Statistical planning and analysis of data Materiaux métalliques Essais de fatigue Programmation et analysestatistiquededonnees Reference number ISO 12107:2012(E) ISO @ISO2012 I by IHS under lic No reproduction or networking permitted without license from IHS Not for Resale ISO 12107:2012(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 copyright@iso.org Web www.iso.org Published in Switzerland ISO 2012-All rights reserved or networking permited withoutlicense from IHS Not for Resale ISO 12107:2012(E) Contents Page Foreword .iv Introduction 1 Scope.. 1.1 Objectives 1.2 Fatigue properties to be analysed 1.3 Limit of application .. 2 Normative references. 3 Terms and definitions... 3.1 Terms related to statistics. 3.2 Terms related to fatigue Statistical distributions in fatigue properties 3 4.1 Concept of distributions in fatigue... 3 4.2 Distribution of fatigue life... 4 4.3 Distribution of fatigue strength . 5 5 Statistical planning of fatigue tests.. 5.1 Sampling... 5 5.2 Allocation of specimens for testing . 6 6 Statistical estimation of fatigue life at a given stress .. 6.1 Testing to obtain fatigue life data... 6 6.2 Plotting data on normal probability paper... 6.3 Estimating distribution parameters.... 6.4 Quantitativeevaluationoftheassumptionofnormality 6.5 Estimating the lower limit of the fatigue life ... 7 Statistical estimation of fatigue strength at a given fatigue life 8 7.1 Testing to obtain fatigue strength data ... 8 7.2 Statistical analysis of test data... 8 7.3 Estimating the lower limit of the fatigue strength. 9 7.4 Modified method when standard deviation is known. 8 Statistical estimation of the S-N curve.. 9 8.1 Introduction.. 9 8.2 Estimation of regression parameters. 13 8.3 Analysis approach .. 15 8.4 Calculation of the lower tolerance limit. 21 8.5 Experimental plan for the development of S-N curves .... .22 9 Test report ... .22 9.1 Presentation of test results 22 9.2 Fatigue strength at a given life. .22 9.3 S-N curve. 23 Annex A (informative) Examples of applications .24 Annex B (informative) Statistical tables .34 Bibliography. 36 ili ed without license from IHS Not for Resale