Experimental Characterization of Advanced Composite Materials Third Edition Donald F.AdamsLeif A.CarlssonR.Byron Pipes CRC CRC PRESS Boca Raton London New York Washington,D.C
CRC PRESS Boca Raton London New York Washington, D.C. Donald F. Adams • Leif A. Carlsson • R. Byron Pipes Third Edition Experimental Characterization of Advanced Composite Materials
Library of Congress Cataloging-in-Publication Data Carlsson,Leif A.,1952- Experimental characterization of advanced composite materials/Leif Carlsson, Donald F.Adams,R.Byron Pipes.-3rd ed. p.cm. Includes bibliographical references and index. ISBN1-58716-100-1 1.Composite materials-Testing.I.Adams,Donald Frederick,1935-II.Pipes,R. Byron.III.Title. TA418.9.C6C3242002 620.118'0287-dc21 2002073579 CIP This book contains information obtained from authentic and highly regarded sources.Reprinted material is quoted with permission,and sources are indicated.A wide variety of references are listed.Reasonable efforts have been made to publish reliable data and information,but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical,including photocopying,microfilming,and recording,or by any information storage or retrieval system,without prior permission in writing from the publisher. The consent of CRC Press LLC does not extend to copying for general distribution,for promo- tion,for creating new works,or for resale.Specific permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC,2000 N.W.Corporate Blvd.,Boca Raton,Florida 33431. Trademark Notice:Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation,without intent to infringe. Visit the CRC Press Web site at www.crcpress.com ©2003 by CRC Press LLC No claim to original U.S.Government works International Standard Book Number 1-58716-100-1 Library of Congress Card Number 2002073579 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper
This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage or retrieval system, without prior permission in writing from the publisher. The consent of CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC, 2000 N.W. Corporate Blvd., Boca Raton, Florida 33431. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Visit the CRC Press Web site at www.crcpress.com © 2003 by CRC Press LLC No claim to original U.S. Government works International Standard Book Number 1-58716-100-1 Library of Congress Card Number 2002073579 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper Library of Congress Cataloging-in-Publication Data Carlsson, Leif A., 1952– Experimental characterization of advanced composite materials / Leif Carlsson, Donald F. Adams, R. Byron Pipes. — 3rd ed. p. cm. Includes bibliographical references and index. ISBN 1-58716-100-1 1. Composite materials—Testing. I. Adams, Donald Frederick, 1935– II. Pipes, R. Byron. III. Title. TA418.9.C6 C324 2002 620.1′18′0287—dc21 2002073579 CIP TX001_FM_Frame Page 4 Tuesday, September 24, 2002 11:19 AM
Dedications D.F.A.:To my wife and very best friend,Roberta, mother of our four children,Dave,Dan,Doug,and Jayne L.A.C.:To the memory of Dr.Alf de Ruvo, coadvisor of my Ph.D.dissertation and long-time friend. R.B.P.:To the memory of Professor Roy McCullough for his three decades of warm and supportive friendship. ©2003 by CRC Press LLC
Dedications D.F.A.: To my wife and very best friend, Roberta, mother of our four children, Dave, Dan, Doug, and Jayne L.A.C.: To the memory of Dr. Alf de Ruvo, coadvisor of my Ph.D. dissertation and long-time friend. R.B.P.: To the memory of Professor Roy McCullough for his three decades of warm and supportive friendship. TX001_FM_Frame Page 5 Saturday, September 21, 2002 4:46 AM © 2003 by CRC Press LLC
Preface The experimental characterization of composite materials has been an elusive topic,because it has been a continually evolving one.As new types of com- posites have been developed and new applications found,new testing chal- lenges have continually evolved.For example,in the 1960s the primary structural composite material available to compete with metals consisted of carbon fiber in a brittle epoxy matrix,a material of relatively low toughness. Thus,toughness as a property was de-emphasized by the composite materials community.However,by the beginning of the 1980s,many new matrix mate- rials,e.g.,toughened epoxies and high-temperature thermoplastics,were being incorporated to produce toughened composites.Obviously,the need quickly arose to develop test methods for ranking the relative toughness of composite materials.But there are multiple definitions of toughness,damage tolerance,and the effect of defects.Soon many test methods not previously applied to composites were being proposed,including Mode I,II,and mixed- mode fracture mechanics,beam and plate impact,compression after plate impact,and open-hole tension and compression. This evolution of test methods to meet new demands has continued over the years as additional aspects have risen in importance;e.g.,influences of temperature,moisture,solvents,and other factors affecting durability. Improvements in fiber-matrix interfacial bonding,the introduction of organic fibers such as aramid,polyethylene,liquid crystal polymer,and natural forms such as hemp and jute,and ultrahigh modulus inorganic fibers,particularly carbon,also have occurred.Likewise,new classes of matrix materials such as bismalimides,polyimides,and many others have necessitated still more test methods,or revisions of existing ones. As we now enter the 21st century,applications of all types of composite materials to commercial products are being emphasized.In anticipation of this development,the 1990s were a period of consolidation of test methods, and attempts to better understand those methods being used.Thus,the present text comes at an opportune time,i.e.,when the evolution of test methods is in a relatively stable period and definitive recommendations can be made.The goal of this text is to present primarily only those mechanical test methods that have achieved some consensus as being the best presently available,recognizing that "best"is often subjective. The primary audience for this text will be university,junior college,and technical school undergraduate students,and beginning university graduate students,taking a course in experimental mechanics of composite materials. However,this text also addresses a much larger audience.Quite frequently, engineers and technicians in industry and government laboratories are ©2003 by CRC Press LLC
Preface The experimental characterization of composite materials has been an elusive topic, because it has been a continually evolving one. As new types of composites have been developed and new applications found, new testing challenges have continually evolved. For example, in the 1960s the primary structural composite material available to compete with metals consisted of carbon fiber in a brittle epoxy matrix, a material of relatively low toughness. Thus, toughness as a property was de-emphasized by the composite materials community. However, by the beginning of the 1980s, many new matrix materials, e.g., toughened epoxies and high-temperature thermoplastics, were being incorporated to produce toughened composites. Obviously, the need quickly arose to develop test methods for ranking the relative toughness of composite materials. But there are multiple definitions of toughness, damage tolerance, and the effect of defects. Soon many test methods not previously applied to composites were being proposed, including Mode I, II, and mixedmode fracture mechanics, beam and plate impact, compression after plate impact, and open-hole tension and compression. This evolution of test methods to meet new demands has continued over the years as additional aspects have risen in importance; e.g., influences of temperature, moisture, solvents, and other factors affecting durability. Improvements in fiber–matrix interfacial bonding, the introduction of organic fibers such as aramid, polyethylene, liquid crystal polymer, and natural forms such as hemp and jute, and ultrahigh modulus inorganic fibers, particularly carbon, also have occurred. Likewise, new classes of matrix materials such as bismalimides, polyimides, and many others have necessitated still more test methods, or revisions of existing ones. As we now enter the 21st century, applications of all types of composite materials to commercial products are being emphasized. In anticipation of this development, the 1990s were a period of consolidation of test methods, and attempts to better understand those methods being used. Thus, the present text comes at an opportune time, i.e., when the evolution of test methods is in a relatively stable period and definitive recommendations can be made. The goal of this text is to present primarily only those mechanical test methods that have achieved some consensus as being the best presently available, recognizing that “best” is often subjective. The primary audience for this text will be university, junior college, and technical school undergraduate students, and beginning university graduate students, taking a course in experimental mechanics of composite materials. However, this text also addresses a much larger audience. Quite frequently, engineers and technicians in industry and government laboratories are TX001_FM_Frame Page 7 Saturday, September 21, 2002 4:46 AM © 2003 by CRC Press LLC
assigned composite material testing responsibilities,but have little or no prior experience.These individuals are associated with a wide range of organizations,including corporate research,federal laboratories,university research,material suppliers,contract design organizations,and custom fabrication shops.They need to choose among competing test methods,to perform or supervise the performance of mechanical testing,and then inter- pret the experimental data obtained.In this sense this text complements American Society for Testing and Materials (ASTM)and other standards This text is sufficiently straightforward and concise in its presentation to appeal to this group if individuals who need a quick start. Another potential audience includes those who attend composite material characterization short courses and tutorials.The present text,because of its concise wording and numerous figures and tables,will serve both as a set of course notes and a permanent reference source of topics covered. The 14 chapters of the text are organized to meet the class laboratory schedule needs of a one-semester or one-quarter course.Specific topics (chapters)can be deleted as required to fit the actual time available.The text is intended to be self-contained,with no reference texts required. The first four chapters provide an introduction to the special terminology and conventions that have evolved related to composite materials(Chapter 1), a summary of the unique analysis methods and data reduction formulas required(Chapter 2),sufficient laminate processing information to permit the reader to fabricate his or her own composites for testing (Chapter 3),and details of specimen preparation and testing equipment required(Chapter 4). Chapters 5 through 10 each cover a specific aspect of lamina testing, including tension,compression,shear,flexure,off-axis tension,and ther- moelastic response.Extensions of these principles to laminate mechanical and thermoelastic response are covered in Chapters 11 and 12,respec- tively.The composite durability issues referred to previously are detailed in Chapter 13(effects of defects)and Chapter 14(fracture mechanics).Of particular note among the appendices is Appendix C,which contains a sample laboratory report.This is intended to serve as a guide for the reader in the preparation of an acceptable form of data analysis and presentation. D.F.A.,Laramie,WY L.A.C.,Boca Raton,FL R.B.P.,Akron,OH ©2003 by CRC Press LLC
assigned composite material testing responsibilities, but have little or no prior experience. These individuals are associated with a wide range of organizations, including corporate research, federal laboratories, university research, material suppliers, contract design organizations, and custom fabrication shops. They need to choose among competing test methods, to perform or supervise the performance of mechanical testing, and then interpret the experimental data obtained. In this sense this text complements American Society for Testing and Materials (ASTM) and other standards. This text is sufficiently straightforward and concise in its presentation to appeal to this group if individuals who need a quick start. Another potential audience includes those who attend composite material characterization short courses and tutorials. The present text, because of its concise wording and numerous figures and tables, will serve both as a set of course notes and a permanent reference source of topics covered. The 14 chapters of the text are organized to meet the class laboratory schedule needs of a one-semester or one-quarter course. Specific topics (chapters) can be deleted as required to fit the actual time available. The text is intended to be self-contained, with no reference texts required. The first four chapters provide an introduction to the special terminology and conventions that have evolved related to composite materials (Chapter 1), a summary of the unique analysis methods and data reduction formulas required (Chapter 2), sufficient laminate processing information to permit the reader to fabricate his or her own composites for testing (Chapter 3), and details of specimen preparation and testing equipment required (Chapter 4). Chapters 5 through 10 each cover a specific aspect of lamina testing, including tension, compression, shear, flexure, off-axis tension, and thermoelastic response. Extensions of these principles to laminate mechanical and thermoelastic response are covered in Chapters 11 and 12, respectively. The composite durability issues referred to previously are detailed in Chapter 13 (effects of defects) and Chapter 14 (fracture mechanics). Of particular note among the appendices is Appendix C, which contains a sample laboratory report. This is intended to serve as a guide for the reader in the preparation of an acceptable form of data analysis and presentation. D.F.A., Laramie, WY L.A.C., Boca Raton, FL R.B.P., Akron, OH TX001_FM_Frame Page 8 Tuesday, September 24, 2002 11:20 AM © 2003 by CRC Press LLC