_STP_486-1971.pdf

DAMAGE TOLERANCE IN AIRCRAFT STRUCTURES A symposium presented at the Seventy-third Annual Meeting AMERICAN SOCIETY FOR TESTING AND MATERIALS Toronto,Ontario,Canada,21-26 June 1970 ASTM SPECIAL TECHNICAL PUBLICATION 486 List price$19.50 04-486000-30 lj AMERICAN SOCIETY FOR TESTING AND MATERIALS 1 916 Race Street,Philadelphia,Pa.19103 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:01:21 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.()BY AMERICAN SOCIETY FOR TESTING AND MATERIALS 1971 Library of Congress Catalog Card Number:74-152130 ISBN O-8031-0072-8 NOTE The Society is not responsible,as a body,for the statements and opinions advanced in this publication Printed in Lutherville-Timonium,Md.May 1971 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:01:21 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Foreword The Symposium on Damage Tolerance in Aircraft Structures was con-ducted in two sessions at the Seventy-third Annual Meeting of the American Society for Testing and Materials,held in Toronto,Ontario,Canada,21-26 June 1970.The symposium was sponsored by ASTM Committee E-9 on Fatigue.M.S.Rosenfeld,of the Naval Air Development Center,served as symposium chairman,with P.C.Paris,Del Research Corp.,Hellertown,Pa.,and R.J.Hebert,Canadair,Ltd.,Montreal,Ontario,presiding as chairmen of the first and second sessions,respectively.Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:01:21 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Related ASTM Publications Structural Fatigue in Aircraft,STP 404(1966),$18.50 Fatigue at High Temperature,STP 459(1969),$11.25 Effects of Environment and Complex Load History on Fatigue Life,STP 462(1970),$22.00 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:01:21 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Contents Introduction vii The Dependence of Fatigue Crack Propagation on Strain Energy Release Rate and Crack Opening Displacement-J.M.nARSOM 1 Effect of Thickness on the Fracture Toughness of 7075 Aluminum in the T6 and T73 Conditions-F.c.ALLEN 16 The Influence of Curvature on Stress Intensity at the Tip of a Circumferential Crack in a Cylindrical Shell-N.J.L ADAMS 39 Evaluation and Prediction of the Re,dual Strength of Center Cracked Tension Panels-c.E.FEDDERSEN 50 Fatigue Crack Propagation in Stiffened Panels-c.c.PoE,JR.79 Material Toughness and Residual Steagth of Damage Tolerant Aircraft Structures-A.F.LIU AND J.C.EKVALL 98 An Approach to Predicting the Growth to Failure of Fatigue Cracks Sub-jected to Arbitrary Uniaxial Cyclic Loading-T.R.BRUSSAT 122 Initiation and Growth of Fatigue Cracks in and Residual Strength of the F-100 Wing-w.o.GRAZIANO AND(3.E.FITCH,JR.144 Development of the Fail-safe Design Features of the DC-10-T.SWXFT 164 The Ballistic Damage Characteristics and Damage Tolerance of Wing Struc-tural Elements-J.E.JENSEN 215 The Significance of Fatigue Crack Closure-WOLF ELBER 230 Crack Propagation in Helicopter Rotor Blades-M.J.RICH 243 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:01:21 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Introduction In the past aircraft were designed for maximum performance,with par-ticular attention given to range,altitude,speed,and pay load.Structural concepts and materials which provided minimum weight were used with little consideration for damage tolerance or,in the case of military aircraft,structural vulnerability.The current emphasis on safety,with longer intervals between maintenance periods to increase aircraft availability,has required more intensive consideration on the part of the designer of crack propagation characteristics and residual strength of flight structures.Information on the growth of cracks in engineering structures and the residual strength of cracked structures is necessary for the prediction of service lives of structures subjected to fatigue loading and for the establish-ment of safe inspection intervals.This symposium provided an effective means of exchanging technological advances in fatigue crack propagation and fracture theory.The specific objectives of the symposium were 1.To review the state of aircraft structural analysis for structures with propagating cracks.2.To present recent advancements in research into basic mechanisms of crack propagation and residual strength of aircraft structures.3.To provide a review of fracture mechanics as applied to the assessment of structural vulnerability and residual strength of materials and structures.Because of the limited time avai