ISO INTERNATIONAL STANDARD 7626-2 Secondedition 2015-04-01 Mechanical vibration and shock - Experimental determination of mechanical mobility Part 2: Measurements using single-point translation excitation with an attached vibration exciter Vibrationsetchocs-Déterminationexpérimentaledelamobilite mecanique- Partie 2: Mesurages avec utilisation d'une excitation de translation en un seul point, au moyen d'un génerateur de vibrations solidaire de ce point Referencenumber IS0 7626-2:2015(E) LSO Intermational Organization for Standardization @IS02015 t license from IHS IS0 7626-2:2015(E) COPYRIGHTPROTECTEDDOCUMENT ISO2015 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 Case postale 56.CH-1211 Geneva 20 Tel. +4122 749 0111 Fax +41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland PrganizationforStandardization networking permited without license from IHS NotforResale, 2015/6/207:55:59 IS0 7626-2:2015(E) Contents Page Foreword ..iv Introduction.. 1 Scope. 2 Normative references 3 Terms and definitions ..1 4 Overall configurationofthemeasurementsystem 5 Support of the structure under test. .3 5.1 General .3 5.2 Grounded measurements .3 5.3 Ungrounded measurements .3 6 Excitation. .4 6.1 General .4 6.2 Excitation waveforms 4 6.3 Vibration exciters. 6.4 Avoidanceofspuriousforcesandmoments .8 7 Measurement of the exciting force and resulting motionresponse .9 7.1 General 7.2 Attachment oftransducers .9 7.3 Mass loading and mass cancellation .10 7.4 Signal amplifiers ..10 7.5 Calibrations .11 8 Processing of the transducer signals ..14 8.1 Determinationofthefrequency-responsefunction ..14 8.2 Filtering. .14 8.3 Avoidance of saturation .15 8.4 Frequency resolution. .15 Control of theexcitation .16 9.1 General. .16 9.2 Time required for sinusoidal excitation .16 9.3 Time requiredfor random excitation ..17 9.4 Dynamic range. ..18 10 Tests for valid data .18 11 Modal parameteridentification .19 AnnexA(normative)Testsforvalidityofmeasurementresults .21 Annex B (normative) Requirements for excitationfrequency increments and duration ..24 AnnexC(informative)Modalparameteridentification .26 Bibliography .27 iii ithout license from IHS