Advanced Ultrasonic Methods for Material and Structure Inspection E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 518

Veröffentlichungsjahr: 2013

Beschreibung

Ultrasonic signals are increasingly being used for predicting material behavior, both in an engineering context (detecting anomalies in a variety of structures) and a biological context (examining human bones, body parts and unborn fetuses). Featuring contributions from authors who are specialists in their subject area, this book presents new developments in ultrasonic research in both these areas, including ultrasonic NDE and other areas which go beyond traditional imaging techniques of internal defects. As such, both those in the biological and physical science communities will find this an informative and stimulating read.

Leseprobe

Table of Contents

Preface

Chapter 1. An Introduction to Failure Mechanisms and Ultrasonic Inspection

1.1. Introduction

1.2. Issues in connecting failure mechanism, NDE and SHM

1.3. Physics of failure of metals

1.4. Physics of failure of ceramic matrix composites

1.5. Physics of failure and NDE

1.6. Elastic waves for NDE and SHM

1.7. Conclusion

1.8. Bibliography

Chapter 2. Health Monitoring of Composite Structures Using Ultrasonic Guided Waves

2.1. Introduction.

2.2. Guided (Lamb) wave propagation in plates

2.3. Passive ultrasonic monitoring and characterization of low velocity impact damage in composite plates

2.4. Autonomous active damage monitoring in composite plates

2.5. Conclusion

2.6. Bibliography

Chapter 3. Ultrasonic Measurement of Micro-acoustic Properties of the Biological Soft Materials

3.1. Introduction

3.2. Materials and methods

3.3. Results

3.4. Conclusion

3.5. Bibliography

Chapter 4. Corrosion and Erosion Monitoring of Pipes by an Ultrasonic Guided Wave Method

4.1. Introduction

4.2. Ultrasonic guided wave monitoring of average wall thickness in pipes .

4.3. Experimental validation

4.4. Conclusion

4.5. Bibliography

Chapter 5. Modeling of the Ultrasonic Field of Two Transducers Immersed in a Homogenous Fluid Using the Distributed Point Source Method

5.1. Introduction

5.2. Theory

5.3. Numerical results and discussion

5.4. Conclusion

5.5. Acknowledgments

5.6. Bibliography

Chapter 6. Ultrasonic Scattering in Textured Polycrystalline Materials

6.1. Introduction

6.2. Preliminary elastodynamics

6.3. Cubic crystallites with orthorhombic texture

6.4. Attenuation in hexagonal polycrystals with texture

6.5. Diffuse backscatter in hexagonal polycrystals

6.6. Conclusion

6.7. Acknowledgments

6.8. Bibliography

Chapter 7. Embedded Ultrasonic NDE with Piezoelectric Wafer Active Sensors

7.1. Introduction to piezoelectric wafer active sensors

7.2. Guided-wave ultrasonic NDE and damage identification

7.3. PWAS ultrasonic transducers

7.4. Shear layer interaction between PWAS and structure

7.5. Tuned excitation of Lamb modes with PWAS transducers

7.6. PWAS phased arrays

7.7. Electromechanical impedance method for damage identification

7.8. Damage identification in aging aircraft panels

7.9. PWAS Rayleigh waves NDE in rail tracks

7.10. Conclusion

7.11. Acknowledgments

7.12. Bibliography

Chapter 8. Mechanics Aspects of Non-linear Acoustic Signal Modulation due to Crack Damage

8.1. Introduction

8.2. Damage in concrete

8.3. Stress wave modulation

8.4. Summary and conclusion

8.5. Bibliography

Chapter 9. Non-contact Mechanical Characterization and Testing of Drug Tablets

9.1. Introduction

9.2. Drug tablet testing for mechanical properties and defects

9.3. Non-contact excitation and detection of vibrational modes of drug tablets

9.4. Mechanical quality monitoring and characterization

9.5. Conclusions, comments and discussions

9.6. Acknowledgments

9.7. Bibliography

Chapter 10. Split Hopkinson Bars for Dynamic Structural Testing

10.1. Introduction

10.2. Split Hopkinson bars

10.3. Using bar waves to determine fracture toughness

10.4. Determination of dynamic biaxial flexural strength

10.5. Dynamic response of micromachined structures

10.6. Conclusion

10.7. Bibliography

First published in Great Britain and the United States in 2007 by ISTE Ltd

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd

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© ISTE Ltd, 2007

The rights of Tribikram Kundu to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Advanced ultrasonic methods for material and structure inspection/edited by Tribikram Kundu.

    p. cm.

  Includes bibliographical references and index.

  ISBN-13: 978-1-905209-69-9

  ISBN-10: 1-905209-69-X

  1. Ultrasonic testing. I. Kundu, T. (Tribikram)

  TA417.4.A38 2006

  620.1'1274--dc22

2006032329

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN 10: 1-905209-69-X

To my wife, Nupur, our daughters, Ina and Auni and our parents, Makhan Lal Kundu, Sandhya Rani Kundu, Jyotirmoy Naha and Rubi Naha

Preface

Today, the ultrasonic signal is being used for predicting material behavior, characterizing (detecting internal anomalies in) a variety of engineering structures, as well as for inspecting human body parts like tumors, bones, and unborn fetuses. Because of the ever-increasing popularity of the ultrasonic techniques in a wide range of applications, this technology has received a lot of attention from the research community. This book presents some new developments in ultrasonic research for material and structure inspection. Application areas cover both engineering and biological materials.

Some of the recent advances in the science and technology of ultrasonic NDE and other areas of research on ultrasonic technology that go beyond the traditional imaging techniques of internal defects are covered in this book. New inspection and material characterization techniques applied to engineering structures, as well as biological materials, are presented here. Ten chapters cover a wide range of application areas of the ultrasonic technology. From the first chapter the reader will learn various failure mechanisms associated with different types of engineering materials and will get an overview of the current ultrasonic NDE/SHM techniques. This chapter will help to bridge the gap between the materials scientists and the mechanics community in their understanding and approach to the nondestructive evaluation and health monitoring of engineering materials and structures. From the subsequent chapters the reader will learn:

– how to measure and predict the impact damage in composite panels by analyzing the impact damage generated ultrasonic signals: a combined experimental and theoretical study of the Lamb wave propagation and generation by the low velocity impact in composite panels is important for this purpose, and is presented here in the hope that it will eventually develop an impact monitoring system in the future;

– how to measure and interpret the ultrasonic properties of soft biological tissues: scanning acoustic microscopes can measure attenuation and wave speed in soft tissues. From these properties the biomechanics of the tissues can be assessed that might improve our understanding of diseases from a micro-mechanical point of view;

– how to monitor corrosion and erosion damages in pipelines using cylindrical guided waves, which guided wave mode is most efficient to detect the wall thickness reduction over a long range and how to generate this mode in the pipe;

– how to accurately model the ultrasonic field generated by multiple transducers: in defect detection and health monitoring applications when multiple sensors are used, the accurate modeling of the ultrasonic pressure and velocity fields in the near field region is important. The distributed point source method (DPSM) for modeling the ultrasonic fields including the interaction effects is presented;

– how the ultrasonic wave propagation characteristics, often used for microstructure inspection, are influenced by the texture. The propagation and scattering of ultrasonic waves in textured polycrystals are discussed in Chapter 6. This is important for material microstructure inspection by ultrasonic waves;

– how embedded piezoelectric ultrasonic sensors are used for health monitoring of large plate type structures. A rigorous study of the interaction between ultrasonic Lamb waves and embedded piezoelectric wafer active sensors is necessary for this purpose;

– what is the effect of cracks on the acoustic signal modulation. What material properties, signal characteristics and crack dimensions affect this modulation. This study is important for gaining knowledge about the material damage and geometric non-linearity from the modulation of the signal propagated through the material;

– how to measure the dynamic response of materials using split Hopkinson bars and what issues are important and how to design the experiments for accurately measuring these dynamic properties.

It is my hope that both biological and physical science communities will gain some new knowledge from this book that will stimulate new research resulting in the development of more innovative ultrasonic technology applications.

I would like to thank the authors for timely submission of their chapters. My special thanks go to Professor Dominique Placko for encouraging me to take this project and to the publisher for giving me this opportunity.

Tribikram Kundu University of Arizona, USA

Chapter 1

An Introduction to Failure Mechanisms and Ultrasonic Inspection1

1.1. Introduction

Future inspections of aerospace systems and other engineering structures are expected to be based on a combination of non-destructive evaluation (NDE) and structural health monitoring (SHM) technologies. Here SHM will be employed online or in real-time to detect damage at a global level and then NDE will be used to characterize the damage in terms of size and physics of the damage mode (or failure mechanism). Proper implementation, correct interpretation of the results and advancement of both these technologies for the analysis of engineering failures will require a certain amount of understanding of material behavior and material damage modes. This chapter is written with this in mind and the objective is to give the reader an overview of various failure mechanisms that can occur in structural metallic materials and ceramic matrix composites. This is then followed with a brief discussion of damage detection techniques using ultrasonic waves in metals and composites. Organic matrix composites have been intentionally omitted due to the limited scope of the chapter.

Continuous, autonomous, real-time, in-service monitoring of the condition of a structure with minimum manual intervention is known as structural health monitoring or SHM. In recent years SHM has received much attention from different disciplines of science and engineering including NDE. Real-time NDE-based sensing methodologies for structural damage and material state are being developed and in order to monitor these states it is important to know what damage and material states are being sensed and how the material state change may be progressing. Without such knowledge the sensor output generated during flight or during system operation may prove to be of little value.

The purpose of this chapter is not to review the SHM-related investigations that have been carried out so far, but to bridge the gap between the mechanics and materials community on SHM-related knowledge and understanding. The mechanics community often fails to see the importance of the type of material used when designing an SHM system for a specific structural component or material. As an example, the analysis and design-based on Young's modulus and Poisson's ratio does not necessarily produce two SHM systems for two different materials because the failure mechanisms for the two materials can be completely different. A good understanding of different failure mechanisms for various materials is needed for designing efficient SHM systems for different structural components made of various types of material. Similarly, it is also important for materials scientists to understand the basic mechanics behind SHM systems for better communication and collaboration with the mechanics community. This collaboration is important for jointly developing appropriate SHM systems. This chapter has been written with this goal in mind.

1.2. Issues in connecting failure mechanism, NDE and SHM

Microcrack nucleation, macrocrack formation and crack extension are well understood in metals, ceramics, ceramic matrix composites (CMC), polymer matrix composites and carbon-carbon (C-C) composites. Most of this understanding is based on tests on laboratory samples in well controlled environments and many new materials have been developed in recent years based on such understanding. However, when alloys are scaled up from laboratory samples to large-scale product forms or when the environment changes from that of a laboratory to that of a near-operational environment, an undesired rate of failure progression may occur. The contribution of materials to this undesired effect can be due to composition and processing deviations. For example, chemical composition is not as easy to control in large ingots (e.g. 10,000 lb) as in a small laboratory size ingot (e.g. 100 lb). Similarly, larger variations in properties occur while processing large ingots during component manufacturing (e.g. mid-thickness properties can vary substantially from surface properties). Manufacturing processes can also introduce, for example, tensile residual stresses or unintentional sharp radii which may curtail ductility or cause faster crack propagation rates. Fracture modes can thus be different or accentuated in components as compared to those in the laboratory samples. Life prediction models also exist for many of the materials to predict their fatigue life in laboratory setting and to some extent in operational/service environments. Here again, chemical composition variations, impurity segregation, and manufacturing processes can introduce large scatter and a reduction in mechanical properties compared to that in the laboratory samples. This, combined with unanticipated changes or ill-defined operational environments, can lead to inaccurate estimations of service life.