Earthquakes and Acoustic Emission BALKEMA – Proceedings and Monographs in Engineering, Water and Earth Sciences Earthquakes and Acoustic Emission Edited by Alberto Carpinteri & Giuseppe Lacidogna Department of Structural Engineering and Geotechnics, Politecnico di Torino, Italy LONDON / LEIDEN / NEW YORK / PHILADELPHIA / SINGAPORE Cover photographs: left; view of the Astesiano Tower, one of the medieval towers still rising in Alba (an ancient town in Piemonte, Italy), right; a thermographic view of the same tower. Photos by courtesy of Professor Alberto Carpinteri and Dr. Giuseppe Lacidogna. Taylor & Francis is an imprint of the Taylor & Francis Group, an informa business This edition published in the Taylor & Francis e-Library, 2007. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.” © 2007 Taylor & Francis Group, London, UK All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without written prior permission from the publishers. Although all care is taken to ensure integrity and the quality of this publication and the information herein, no responsibility is assumed by the publishers nor the author for any damage to the property or persons as a result of operation or use of this publication and/or the information contained herein. Published by: Taylor & Francis/Balkema P.O. Box 447, 2300 AK Leiden, The Netherlands e-mail: [email protected] www.balkema.nl, www.taylorandfrancis.co.uk, www.crcpress.com Library of Congress Cataloging-in-Publication Data Earthquakes and acoustic emission / edited by Alberto Carpinteri & Giuseppe Lacidogna. p. cm. Includes bibliographical references and index. ISBN 978-0-415-44402-6 (hardcover : alk. paper) 1. Fracture mechanics. 2. Concrete—Cracking. 3. Buildings—Earthquake effects. 4. Acoustic emission testing. 5. Seismic waves. I. Carpinteri, A. II. Lacidogna, Giuseppe. TA409.E28 2007 620.1'126—dc22 2007019363 ISBN 0-203-93611-6 Master e-book ISBN ISBN13: 978-0-415-44402-6 (Hbk) ISBN13: (ebook): 978-0-203-93611-5 Contents Preface IX 1 Seismic Mechanics and Earthquakes 1.1 Earthquake phenomenology and dynamics THE SCALING OF GEOLOGICAL FAULTS 3 C.H. Scholz EFFECTS OF NONLINEAR WEAKENING ON EARTHQUAKE SOURCE SCALINGS 9 J.-P. Ampuero SEISMIC ENERGY RADIATION FROM DYNAMIC FAULTING 17 R. Madariaga DAMAGE RHEOLOGY MODEL AND DECAY LAW OF AFTERSHOCK ACTIVITY 23 V. Lyakhovsky & Y. Ben-Zion SPECTRAL ELEMENT SIMULATION OF RUPTURE DYNAMICS 33 J.-P. Vilotte & G. Festa 1.2 Mechanics of friction and faulting NON-LINEAR SLIP-WEAKENING IN A ROTARY GOUGE FRICTION EXPERIMENT 43 G. Chambon, J. Schmittbuhl & A. Corfdir DOES ELASTIC REBOUND THEORY APPLY TO SEISMIC FAULTS? 51 A. Ziv, A. Cochard & J. Schmittbuhl CORRELATIONS OF STRESS DISTRIBUTIONS ALONG THE FAULT: FROM LABORATORY FRACTURE ROUGHNESS TO FAULT ASPERITY SQUEEZE 57 J. Schmittbuhl, G. Chambon, A. Hansen & M. Bouchon VI Contents DETACHMENT WAVES AND THE ONSET OF FRICTIONAL SLIP 65 S.M. Rubinstein, G. Cohen & J. Fineberg CRACK-LIKE AND PULSE-LIKE DYNAMIC FRICTIONAL SLIDING 71 D. Coker, G. Lykotrafitis, A. Needleman & A.J. Rosakis 2 Structural Failure and Acoustic Emission 2.1 AE theoretical studies IDENTIFICATION OF MICROCRACKING PROCESS IN FRACTURE PROCESS ZONE BY AE 79 M. Ohtsu CONSEQUENCES OF ACOUSTIC EMISSION ON CRACK SPEED AND ROUGHNESS EXPONENT IN BRITTLE DYNAMIC FRACTURE 89 A. Parisi & R.C. Ball FAILURE TIME, CRITICAL BEHAVIOUR AND ACTIVATION PROCESSES IN CRACK FORMATION 95 S. Ciliberto, S. Deschanel, A. Guarino, S. Santucci, R. Scorretti & L. Vanel RESPONSE OF FRACTURE NUCLEATION SITE TO WEAK MECHANICAL PULSES 103 V.S. Kuksenko & E.E. Damaskinskaya FRACTURE IN TWO DIMENSIONS (IN PAPER): ACOUSTIC EMISSION STUDIES AND THEORETICAL LESSONS 109 L.I. Salminen, J. Rosti, J.M. Pulakka & M.J. Alava 2.2 AE testing on concrete and concrete structures MICROMECHANICS OF CORROSION CRACKING IN REINFORCED CONCRETE BY AE 119 F. Uddin A.K.M. & M. Ohtsu DAMAGE MECHANICS OF CARBONATED CONCRETE BY AE RATE-PROCESS ANALYSIS 129 T. Suzuki, G. Komeno & M. Ohtsu Contents VII BRAZILIAN TEST OF CONCRETE EVALUATED BY AE 139 H.W. Reinhardt, F. Finck, C. Grosse & J. Kurz 2.3 AE testing on steel, composites and other materials EVOLUTION OF DAMAGE ACCUMULATION IN LOW-CARBON STEEL IN TENSION CONDITION 149 M.R. Tyutin, L.R. Botvina, N.A. Zharkova, T.B. Petersen & J.A. Hudson FATIGUE PERFORMANCE OF SANDWICH COMPOSITES 155 B. Shafiq, A. Quispitupa & F. Just ON-PROCESS MONITORING OF CERAMICS AND CERAMIC COATINGS BY LASER AE 163 M. Enoki & S. Nishinoiri FRACTURING, ACOUSTIC EMISSION, AND NUMERICAL SIMULATION OF GRANITE UNDER MODE II LOADING 171 O. Stephansson, S. Stanchits, T. Backers, G. Dresen & B. Shen 2.4 AE structural monitoring and damage assessment DAMAGE QUANTIFICATION FOR CONCRETE STRUCTURES BY IMPROVED b-VALUE ANALYSIS OF AE 181 T. Shiotani, X. Luo, H. Haya & M. Ohtsu STRUCTURAL MONITORING AND LIFE-TIME ASSESSMENT OF MEDIEVAL TOWERS 191 A. Carpinteri & G. Lacidogna Author index 201 Preface An earthquake is a sudden movement of the ground caused by the release of elas- tic energy stored in the Earth’s Crust. It causes vibrations that propagate outwards from the source as seismic waves. A similar phenomenon occurs – on a different scale – in structural materials under load and is called Acoustic Emission (AE). While the techniques used in seismology have been well developed over the years, the AE technique has not been fully defined. It can be shown, on the other hand, that the AE method can use many seismic analysis techniques, including the localization of the sources or the inversion of source parameters. The contributions proposed in this book, selected among those presented in Special Sessions at the 11th International Conference on Fracture, Torino (Italy), March 20-25, 2005, aim at providing an outline of the theory and the latest relevant developments on topics related to Earthquakes and Acoustic Emission. During the last few years, numerous experimental techniques have been employed to evaluate fracture processes, and a number of modelling approaches have been developed to predict fracture behaviour. The non-destructive method based on the Acoustic Emission (AE) technique has proved highly effective, espe- cially to check and measure the damage phenomena that take place inside a struc- ture subjected to mechanical loading. The acoustic emission is a consequence of micro-cracks forming and propagat- ing in the material and should thus provide an indirect measure of the damage accumulating in the system. For this reason, AE is often used as a non-destructive tool in material testing and evaluation. Beside these practical applications, under- standing the statistical properties of AE has become a challenging theoretical problem. The distribution of AE amplitudes follows a power law, suggesting an interpretation in terms of critical phenomena and scaling theories. This behaviour has been observed in several materials such as concrete, masonry and rocks, to name just a few. On the other hand, another common and familiar example of this behaviour is the occurrence of earthquakes in a particular seismic zone, where the event amplitudes span from the smallest almost imperceptible vibration of the crust to the largest destructive catastrophic events. The AE monitoring technique is simi- lar to the one employed in earthquake control, where seismic waves reach the monitoring stations placed on the surface of the Earth. Though they take place on very different scales, these two families of phenomena – damage in structural