SAE STP 982-1988 Mechanics of Fatigue Crack Closure.pdf

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1、STP 982 Mechanics of Fatigue Crack Closure J. C. Newman, Jr. and Wolf Elber, editors # ASTM 1916 Race Street Philadelphia, PA 19103 ASTM Publication Code Number (PCN): 04-982000-30 ISBN: 0-8031-0996-2 Library of Congress Catalog Card Number: 88-6303 Copyright by AMERICAN SOCIETY FOR TESTING AND MATE

2、RIALS 1988 NOTE The Society is not responsible, as a body, for the statements and opinions advanced in this pubUcation. Peer Review Policy Each paper published in this volume was evaluated by three peer reviewers. The authors addressed all of the reviewers comments to the satisfaction of both the te

3、chnical editor(s) and the ASTM Committee on Pubhcations. The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s), but also the work of these peer reviewers. The ASTM Committee on Publications acknowledges with appreciation their

4、dedication and contribution of time and effort on behalf of ASTM. Printed in Baltimore, MD June 1988 Foreword The International Symposium on Fatigue Crack Closure was held in Charleston, SC, on 1-2 May 1986. ASTM Committees E-24 on Fracture Testing and E-9 on Fatigue were co- sponsors. J. C. Newman,

5、 Jr., NASA Langley Research Center, and Wolf Elber, U.S. Army Aerostructures Directorate, presided as symposium chairmen and are editors of this pub lication. Herbert F. Hardrath Dedication Herbert F. Hardrath contributed greatly to the success ofASTM Committee E-9 on Fatigue. He was a member of the

6、 committee from 1958 until his death on 25 September 1985, and was the Chairman of Committee E-9 from 1966 to 1971. Herb grew up in Manitowoc, WI, and joined the Navy during World War 11. He received a Bachelor of Science and a Master of Science degree in Civil Engineering at Tulane University and t

7、he Case Institute in Cleveland, OH. In 1947, he joined the National Advisory Committee on Aeronautics (NACA) as a Structural Engineer to forge a fatigue research effort. In 1952, he became the Head of the embryonic Fatigue Section. Under his leadership, the Fatigue Section became a Branch at the Nat

8、ional Aeronautics and Space Administration (NASA) Langley Research Center. In 1970, he was elevated to Assistant Division Chief of the Materials Division. Also in 1970, he received a Special Achievement Award for his amassed contri butions. Herb retired from NASA in 1980. Herb was very active in AST

9、M Committee E-9 on Fatigue. He received the ASTM Award of Merit in 1970 for his many contributions to fatigue research and for the development of fatigue standards. He was invited, in 1970, to present the AIAA Structures Design Lecture. In 1972, he presented the ASTM Gillett Memorial Lecture and, in

10、 1974, he presented the AIAA Dry den Research Lecture. Because of his expertise in fatigue and fracture mechanics. Herb was chosen to be pari of a select group to visit technical centers in the U.S.S.R. in 1976. Herb was the United States delegate to the International Committee on Aeronautical Fatig

11、ue (ICAF) from 1965 to 1980. In 1971, he hosted an international meeting of ICAF in Miami, FL. He presented the Sixth Plantema Memorial Lecture to open the 1977 ICAF meeting in the Federal Republic of Germany. As an eminent fatigue expert, he was chosen to participate in many investigations of fatig

12、ue problems in military and commercial aircraft, such as the B-47, F-111, C-5, and the DC-10. Herb is remembered for more than his technical accomplishments; he was a model for personal integrity and dedication. Contents Introduction 1 MECHANISMS Fatigue Crack Closure: Observations and Technical Sig

13、nificanceJAAP SCHIJVE 5 On Crack Closure in Fatigue Crack GrowthARTHUR J. MCEVILY 35 Plasticity Induced Fatigue Crack ClosureDAVID L. DAVIDSON 44 Overview of Crack Closure at Near-Threshold Fatigue Crack Growth Levels PETER K. LIAW 62 On the Role of Crack Closure Mechanisms in Influencing Fatigue Cr

14、ack Growth FoUovtlng Tensile Overloads in a Titanium Alloy: Near Threshold Versus Higher AK Behaviorc. M. WARD-CLOSE AND R. O. RITCHIE 93 The Effect of Test Frequency and Geometric Asperities on Crack Closure MechanismsJATIN K. SHETH AND WILLIAM W. GERBERICH 112 The Dependence of Crack Closure on Fa

15、tigue Loading Variables STEPHEN J. HUDAK, JR. AND DAVID L. DAVIDSON 121 Crack Closure: Correlation and ConfusionR. W. HERTZBERG, C. H. NEWTON, AND R. JACCARD 139 Crack-Closure Effects on the Growth of Small Surface Cracks in Titanium- Aluminum AlloysJAMES M. LARSEN, JAMES C. WILLIAMS, AND ANTHONY W.

16、 THOMPSON 149 MEASUREMENTS A Comparison of Measurement Methods and Numerical Procedures for the Experimental Characterization of Fatigue Crack ClosureJOHN E. ALLISON, ROLAND C. KU, AND MARK A. POMPETZKI 171 Effects of Load History and Specimen Geometry on Fatigue Craclc Closure MeasurementsNOEL E. A

17、SHBAUGH 186 Comparison of Metliods for Measuring Fatigue Crack Closure in a Thick Specimens. K. RAY AND ALTEN F. GRANDT, JR. 197 A Method for Determining Crack Opening Load from Load-Displacement Data C. DAVIS CARMAN, C. CHRISTOPHER TURNER, AND BEN M. HILLBERRY 214 A Procedure for Standardizing Crac

18、k Closure Levelsj. KEITH DONALD 222 A Statistical Approach to Crack Closure DeterminationLINDA J. ROBERSON AND MARK T. KIRK 230 Determination of Crack Opening Load by Use of Threshold Behavior H. DOKER AND V. BACHMANN 247 Crack Closure Behavior of Surface Cracks Under Pure BendingREZA FOROUGHI AND J

19、OHN C. RADON 260 Closure Measurements on Short Fatigue CracksJOO-JIN LEE AND WILLIAM N. SHARPE, JR. 270 Closure Behavior of Small Cracks Under High Strain Fatigue Histories R. CRAIG MCCLUNG AND HUSEYIN SEHITOGLU 279 Development of Fatigue Crack Closure with the Extension of Long and Short Cracks in

20、Aluminum Alloy 2124: A Comparison of Experimental and Numerical ResultsR. O. RITCHIE, W. YU, D. K. HOLM, AND A. F. BLOM 300 ANALYSES Analysis of Crack Closure Under Plane Strain ConditionsNORMAN A. FLECK AND JAMES C. NEWMAN, JR. 319 Fatigue Crack Closure Outside a Small-Scale Yielding RegimePAUL L.

21、LALOR AND HUSEYIN SEHITOGLU 342 An Analytical Investigation of Plasticity Induced Closure Involving Short Cracks THEODORE NICHOLAS, ANTHONY N. PALAZOTTO, AND EUGENE BEDNARZ 361 Correlation Between Numerically Predicted Crack Opening Load and Measured Load History Dependent Crack Growth ThresholdLOUI

22、S ANQUEZ AND GEORGES BAUDIN 380 Three-Dimensional Finite-Element Simulation of Fatigue Crack Grovith and ClosureR. G. CHERMAHINI, K. N. SHIVAKUMAR, AND J. C. NEWMAN, JR. 398 Predictions of Fatigue Crack Growth Behavior Using a Crack Closure Ligament ModelFARAMARZ KEYVANFAR AND DREW V. NELSON 414 Ana

23、lysis of Crack Opening Beliavior by Application of a Discretized Strip Yield ModelARIJ U. DE KONING AND GERT LIEFTING 437 Analysis of Fatigue Crack Closure Caused by Asperities Using the Modified Dugdale ModelHARUO NAKAMURA AND HIDEO KOBAYASHI 459 Analytical and Experimental Study of Crack Closure B

24、ehavior Based on an S-Shaped Unloading CurveDAI-HENG CHEN AND HIRONOBU NISITANI 475 APPLICATIONS A Simple Crack Closure Model for Predicting Fatigue Crack Growth Under Flight Simulation LoadingDANIEL ALIAGA, ALAIN DAVY, AND HUBERT SCHAFF 491 The Influence of Crack Closure on Fatigue Crack Growth Thr

25、esholds in 2024-T3 Aluminum AlloyEDWARD P. PHILLIPS 505 Correlation of Fatigue Crack Growth Data Obtained at Different Stress Ratios GEOFFREY S. BOOTH AND STEPHEN J. MADDOX 516 Fatigue Crack Closure Behavior of High Stress Ratiosc. CHRISTOPHER TURNER, C. DAVIS CARMAN, AND BEN M. HILLBERRY 528 Using

26、Acoustic Waves for the Characterization of Closed Fatigue Cracks OTTO BUCK, R. BRUCE THOMPSON, AND DAVID K. REHBEIN 536 The Effect of Closure on the Near-Threshold Fatigue Crack Propagation Rates of a Nickel Base SuperalloyLARRY P. ZAWADA AND THEODORE NICHOLAS 548 Influence of Fatigue Crack Wake Len

27、gth and State of Stress on Crack Closure JACK TELESMAN AND DOUGLAS M. FISHER 568 Influence of Some Mechanical Parameters on the Crack Closure Effect in Fatigue Crack Propagation in Aluminum AlloysALAIN CLERIVET AND CLAUDE BATHIAS 583 Three-Dimensional Aspects of Fatigue Crack Closure in Surface Flaw

28、s in Polymethylmethacrylate MaterialWILLIAM A. TROHA, THEODORE NICHOLAS, AND ALTEN F. GRANDT, JR. 598 Effects of Closure on the Fatigue Crack Growth of Small Surface Cracks in a High-Strength Titanium AlloyJAY R. JIRA, TUSIT WEERASOORIYA, THEODORE NICHOLAS, AND JAMES M. LARSEN 617 Summary 637 Index

29、645 STP982-EB/Jun. 1988 Introduction Since the 1950s, the development of the field of “fatigue mechanics“ has been driven by several major observations. First, Irwins crack-tip stress-field analysis and the monumental “stress-intensity factor“ at the Naval Research Laboratory laid the foundation for

30、 future discoveries. Using the “cycUc“ stress-intensity factor range, Paris and Anderson at the Boeing Company produced overwhelming data to support the correlation of fatigue-crack growth rate behavior for metallic materials. At the same time, a group under Hardrath at NACA (later NASA), also study

31、ing the fatigue-crack growth phenomenon, made a similar obser vation concerning a “sharp notch“ stress-field parameter. McEvily and lUgs notch-root stress-field parameter correlated fatigue-crack growth rate data equally as well as the cyclic stress-intensity factor range. Later, it was shown that t

32、he notch-root parameter was directly proportional to the stress-intensity factor. But the eloquence and momentum of the “stress- intensity factor“ quickly displaced the notch-root parameter throughout the aerospace in dustry. Surprisingly, a decade of research on fatigue-crack growth had failed to u

33、ncover the next major discovery. In 1968, Elber at the University of New South Wales observed that fatigue-crack surfaces contact with each other even during tension-tension cyclic loading. This simple observation and the explanation of the crack-closure phenomenon began to explain many other crack-

34、 growth characteristics almost immediately. Hardrath, to whom this symposium and book are dedicated, recognized very quickly the importance of the crack-closure concept in fatigue applications and was instrumental in recruiting Elber to NASA. Since the discovery of “plasticity“ induced closure, seve

35、ral other closure mechanisms have been identified. These new closure mechanisms and the influence of the plastic wake on the local crack-tip strain field have greatly advanced the understanding of fatigue-crack growth and fracture behavior of metallic materials. After nearly 20 years of research, mo

36、st researchers now agree that closure occurs. How ever, no consensus of opinion exists on how to best measure closure effects or crack-opening behavior. Some numerical methods are now available to calculate crack-opening stresses, but they are comphcated to use in practical appUcations. On the other

37、 hand, the crack- closure concept has been extremely useful in many practical applications such as the cor relation of crack-growth rate data and for predicting crack growth under variable-amplitude loading. Therefore, in hopes of advancing the state-of-the-art, an International Symposium 1 Copyrigh

38、t 1988 byASFM International www.astm.org 2 FATIGUE CRACK CLOSURE on Fatigue Crack Closure was organized to provide a forum for exchanging information and experiences on crack-closure measurement techniques, on crack-closure analysis methods, and on practical appUcations of the crack-closure concept.

39、 The symposium was divided into four major topic areas: Mechanisms, Measurements, Analyses and Applications. R. O. Ritchie, A. J. McEvily, E. R Phillips, and J. M. Potter served as respective session chair men. A panel discussion was held in a well-attended evening session. The panelists were A. J.

40、McEvily, P. C. Paris, R. O. Ritchie, and J. Schijve. Keynote addresses were given on “Observations on Understanding Fatigue Crack Growth Through Crack-Closure Effects“ by P. C. Paris and “Fatigue Crack Closure: Observations and Technical Significance“ by J. Schijve. Dr. Paris crack-growth “law“ has

41、revolutionized the treatment of fatigue-crack growth, and this concept has provided a foundation for damage-tolerance analyses. Even Elbers effective stress-intensity factor range has its basis in the cyclic stress-intensity factor range. Professor Schijve has been a leading proponent of the crack-c

42、losure concept, and he has made many lasting contributions to its understanding. The symposium and book are dedicated to the memory of Herbert F. Hardrath. At the symposium, an engraved dedication plaque was presented to Mrs. Gladys Hardrath, his wife, and to his son and daughter. Bill and Janice. A

43、 Special Achievement Award was also presented to Dr. Wolf Elber for his discovery of the fatigue-crack closure mechanism and for his significant contributions to fatigue and fracture mechanics. The award consisted of an engraved wooden plaque to which the “orig inal“ Elber-displacement gage was moun

44、ted. /. C. Newman, Jr. NASA Langley Research Center Hampton, VA 23665; Symposium co-chairman and editor. Mechanisms Jaap Schijve Fatigue Crack Closure: Observations and Technical Significance REFERENCE: Schijve, J., “Fatigue Crack Closure: Observations and Technical Signifi cance,“ Mechanics of Fati

45、gue Crack Closure, ASTM STP 982, J. C. Newman, Jr. and W. Elber, Eds., American Society for Testing and Materials, Philadelphia, 1988, pp. 5-34. ABSTRACT: The meaning of crack closure for fatigue crack growth resistance is discussed under different headings: (1) mechanistic aspects of crack closuree

46、ssential differences be tween microcracks and macrocracks, microstructural influences; (2) direct methods and indirect methods to measure crack closure; (3) numerical aspects of crack closure relations for constant- amplitude loading; and (4) crack closure and variable-amphtude loading. The paper su

47、m marizes the present state of the art. Attention is paid to microstructural aspects, changing crack growth mechanisms under threshold conditions and 3-dimensional aspects including plane strain/plane stress problems. KEY WORDS: fatigue, crack growth, fatigue mechanism, crack closure, constant-ampUt

48、ude loading, variable ampUtude loading, microstructure, survey Nomenclature CA CCT CT K OL S VA UL Constant-amplitude Center cracked tension Compact tension Stress intensity factor Overload Stress Variable-amplitude Underload Subscripts Used for S and K cl Closure eff Effective op Opening th Thresho

49、ld Introduction The historical development of the present knowledge on fatigue crack initiation and fatigue crack growth is marked by a number of characteristic observations and analytical concepts. A brief listing should serve here to set the scope of the present paper. Professor of aircraft materials, Faculty of Aerospace Engineering, Delft University of Technology, 2629 HS Delft, The Netherlands. 5 Copyright 1988 by ASTM International www.astm.org 6 FATIGUE CRACK CLOSURE Microscopical Observations The first observations on early