1、FATIGUE CRACK GROWTH UNDER SPECTRUM LOADS A symposium presented at the Seventy-eighth Annual Meeting AMERICAN SOCIETY FOR TESTING AND MATERIALS Montreal,Canada,23-24 June 1975 ASTM SPECIAL TECHNICAL PUBLICATION 595 R.P.Wei and R.I.Stephens symposium cochairmen List price$34.50 04-595000-30 AMERICAN
2、SOCIETY FOR TESTING AND MATERIALS 1916 Race Street,Philadelphia,Pa.19103 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.?9 AMERICAN SOCIET
3、Y FOR TESTING AND MATERIALS 1976 Library of Congress Catalog Card Number:75-32902 NOTE The Society is not responsible,as a body,for the statements and opinions advanced in this publication.Printed in Tallahassee,Fla.May 1976 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56 EST 2015Dow
4、nloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Foreword The Symposium on Fatigue Crack Growth Under Spectrum Loads was held on 23-24 June 1975 at the Seventy-eighth Annual Meeting of the American Society for Testi
5、ng and Materials in Montreal,Quebec,Canada.Committee E-24 on Fracture Testing of Metals and Committee E-9 on Fatigue sponsored the symposium.R.P.Wei,Lehigh University,and R.I.Stephens,The University of Iowa,served as the symposium cochairmen.Serving as members of the Symposium Organizing/Program Com
6、mittee and as session chairmen were J.M.Barsom,U.S.Steel Corp.;W.G.Clark,Jr.,Westinghouse R&D Center;N.E.Dowling,Westinghouse R&D Center;C.M.Hudson,NASA Langley Research Center;E.K.Walker,Lockheed California Co.;and Howard Wood,AFFDL/FBR,Wright-Patterson AFB.Copyright by ASTM Intl(all rights reserve
7、d);Mon Dec 21 11:17:56 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Related ASTM Publications Handbook of Fatigue Testing,STP 566(1974),$17.25,04-566000-30 Fatigue at Elevated Temperatures,STP 520(197
8、3),$45.50,04-520000-30 Probabilistic Aspects of Fatigue,STP 511(1972),$19.75,04.511000-30 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.A
9、 Note of Appreciation to Reviewers This publication is made possible by the authors and,also,the unheralded efforts of the reviewers.This body of technical experts whose dedication,sacrifice of time and effort,and collective wisdom in reviewing the papers must be acknowledged.The quality level of AS
10、TM publications is a direct function of their respected opinions.On behalf of ASTM we acknowledge with appreciation their contribution.ASTM Committee on Publications Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56 EST 2015Downloaded/printed byUniversity of Washington(University of Wa
11、shington)pursuant to License Agreement.No further reproductions authorized.Editorial Staff Jane B.Wheeler,Managing Editor Helen M.Hoersch,Associate Editor Charlotte E.DeFranco,Senior Assistant Editor Ellen J.McGlinchey,Assistant Editor Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56
12、EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Contents Introduction Observations on the Prediction of Fatigue Crack Growth Propa.gation Under Variable.Amplitude Loading-J.SCHIJVE Loads in Service Diffe
13、rences Between Crack Growth Studies Definition and Measurement of Interaction Effects Interaction Effects in Tests with Overloads or Step Load-ing Interaction Effects in Tests with Program Loading,Ran-dom Loading,or Flight-Simulation Loading Prediction Methods for Variable-Amplitude Loading Conclusi
14、ons SIMPLE SPECTRA:EFFECT OF LOADING VARIABLES Fatigue Crack Growth with Negative Stress Ratio Following Single Overloads in 2024-T3 and 7075-T6 Aluminum Alloys-R.I.STEPHENS,D.K.CHEN,AND B.W.HOM Material and Experimental Procedures Test Results Discussion of Results Summary and Conclusions Effect of
15、 Single Overload/Underload Cycles on Fatigue Crack Propagation-W.X.ALZOS,A.C.SKAT,JR.,AND B.M.HILLBERRY Test Program Experimental Procedure Data ReductionwNumerical Differentiation Test Results Comparison with Crack Closure Conclusions Discussion 3 4 6 8 10 13 16 19 27 28 29 36 37 41 42 43 45 49 53
16、56 58 Copyright by ASTM Intl(all rights reserved);Mon Dec 21 11:17:56 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Effects of Rest Time on Fatigue Crack Retardation and Observa-tions of Crack Closure-W.N.SHARPE,JR.,D.M.CORBLY,AND A.F.GRANDT,JR.Retardation Measurements Surface Measurement of Opening Loads Ultrasonic Measurements Conclusions Discussion Mechanisms of Overload Retardation During Fatig