_STP_842-1984.pdf

DAMAGE TOLERANCE OF METALLIC STRUCTURES:ANALYSIS METHODS AND APPLICATIONS A symposium sponsored by ASTM Committee E-24 on Fracture Testing Los Angeles,CA,29 June 1981 ASTM SPECIAL TECHNICAL PUBLICATION 842 James B.Chang,The Aerospace Corp.,and James L.Rudd,Air Force Wright Aeronautical Laboratories,editors ASTM Publication Code Number(PCN)04-842000-30 181 1916 Race Street,Philadelphia,PA 19103 Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Copyright by AMERICAN SOCIETY FOR TESTING AND MATERIALS 1984 Library of Congress Catalog Card Number:83-73440 NOTE The Society is not responsible,as a body,for the statements and opinions advanced in this pubUcation.Printed in Ann Artor,MI July 1984 Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Foreword The symposium on Damage Tolerance Analysis was presented at Los Angeles,CA,29 June 1981.The symposium was sponsored by ASTM Committee E-24 on Fracture Testing.James B.Chang,The Aerospace Corp.,presided as chairman of the symposium and is coeditor of the publication;James L.Rudd,Wright Aeronautical Laboratories is coeditor of the publication.Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Related ASTM Publications Fatigue Mechanics:Advances in Quantitative Measurement of Physical Damage,STP 811(1983),04-811000-30 Probabilistic Fatigue Mechanics and Fatigue Methods:Applications for Struc-tural Design and Maintenance,STP 798(1983),04-798000-30 Design of Fatigue and Fracture Resistant Structures,STP 761(1982),04-761000-30 Methods and Models for Predicting Fatigue Crack Growth Under Random Load-ing,STP 748(1981),04-748000-30 Effect of Load Variables on Fatigue Crack Initiation and Propagation,STP 714(1980),04-714000-30 Fatigue of Composite Materials,STP 569(1975),04-568000-33 Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.A Note of Appreciation to Reviewers The quality of the papers that appear in this publication reflects not only the obvious efforts of the authors but also the unheralded,though essential,work of the reviewers.On behalf of ASTM we acknowledge with appreciation their dedication to high professional standards and their sacrifice of time and effort.ASTM Committee on Publications Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.ASTM Editorial Staff Janet R.Schroeder Kathleen A.Greene Rosemary Horstman Helen M.Hoersch Helen P.Mahy Allan S.Kleinberg Susan L.Gebremedhin Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Contents Introduction 1 Introduction to Damage Tolerance Analysis Methodology 3 ALTEN F.GRANDT,JR.Damage Accumulation Techniques in Damage Tolerance Analysis 25 ROBERT M.ENGLE,JR.Crack Growth Retardation and Acceleration ModelsCHARLES R.SAFF 36 ASTM Fatigue Life Round-Robin PredictionsJAMES B.CHANG 50 Fracture Analysis of Stiffened StructureTHOMAS SWIFT 69 Application of Fracture Mechanics on the Space Shuttle 108 ROYCE G.FORM AN AND TIANLAI HU Air Force Damage Tolerance Design PhilosophyJAMES L.RUDD 134 Summary 143 Index 147 Copyright by ASTM Intl(all rights reserved);Wed Dec 23 18:09:55 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.STP842-EB/JUI.1984 Introduction In the late 1960s and early 1970s,a number of aircraft structural failures occurred both during testing and in-service.Some of these failures were attrib-uted to flaws,defects,or discrepancies that were either inherent or introduced during the manufacturing and assembly of the structure.The presence of these flaws was not accounted for in design.The design was based on a safe-life fatigue analysis.Mean life predictions were made that were based upon mate-rials unflawed fatigue test data and a conventional fatigue analysis.A scatter factor of four was used to account for initial quality,environment,variation in material properties,and so forth.However,this conventional fatigue(safe-life)analysis approach did not adequately account for the presence and the growth of these flaws.In order to ensure the safety of the aircraft structure,the U.S.Air For