FLAW GROWTH AND FRACTURE

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Proceedings of the Tenth National Synnposium on Fracture Mechanics

A symposiunn sponsored by ASTM Committee E-24 on Fracture Testing of Metals American Society for Testing and Materials Philadelphia, Pa., 23-25 Aug. 1976

ASTM SPECIAL TECHNICAL PUBLICATION 631 J. M. Barsom, symposium chairman

List price $49.75 04-631000-30

AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race Street, Philadelphia, Pa. 19103

© by AMERICAN SOCIETY FOR TESTING AND MATERIALS 1977

Library of Congress Catalog Card Number: 77-73543

NOTE The Society is not responsible, as a body,

for the statements and opinions advanced in this publication.

Printed in Baltimore, Md, October 1977

Foreword This publication, Flaw Growth and Fracture, contains papers presented at

the Tenth National Symposium on Fracture Mechanics which was held 23-25 August 1976 at Philadelphia, Pa. The American Society for Testing and Materials' Commitee E-24 on Fracture Testing of Metals sponsored the symposium. J. M. Barsom, U. S. Steel Corporation, Monroeville, Pa., served as symposium chairman.

Related ASTM Publications

Properties of Materials for Liquefied Natural Gas Tankage, STP 579 (1975), $39.75 (04-579000-30)

Mechanics of Crack Growth, STP 590 (1976), $45.25 (04-590000-30)

Fractography—Microscopic Cracking Process, STP 600, (1976), $27.50 (04-600000-30)

A 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 ASTM publica­tions is a direct function of their respected opinions. On behalf of ASTM we acknowledge with appreciation their contribution.

ASTM Committee on Publications

Editorial Staff

Jane B. Wheeler, Managing Editor Helen M. Hoersch, Associate Editor

Ellen J. McGlinchey, Senior Assistant Editor Kathleen P. Zirbser, Assistant Editor

Sheila G. Pulver, Assistant Editor

Contents

Introduction 1

Fracture Mechanics in the Elastic-Plastic Regime—p. c. PARIS 3 J-Integral—What Is It? 4 Crack-Tip Stress and Strain Fields 9 Linear-Elastic Crack-Tip Stress and Strain Fields 10 Elastic-Plastic Crack-Tip Stress and Strain Fields 10 The Intensely Deformed Nonlinear Zone 12 J-Integral Analysis for Monotonic Loading with Abrupt Failure

or Stable Tearing 14 J-Integral Rate for Time-Dependent Plasticity 15 Application of J-Integral Analysis to Fatigue-Crack Growth 17 Computation Methods and Estimates for J Determination 19 Summary of the Comprehensive Nature of J-Integral Analysis 24 Comparative Applicability of J-Integral and Other Methods 25 Conclusions 26

Path Dependence of the J-Integral and the Role of / as a Parameter Characterizing the Near-Tip Field—R. M. MCMEEKING 2 8

Definition of the J-Integral 30 Path Dependence of the J-Integral 31 Path Dependence of the J-Integral in a Rigid-Plastic Model 35 Crack and Notch-Tip Blunting 38 Deformation Near Notch Tips in Incremental and Deformation

Theory Materials 39

Fracture Analysis Under Large-Scale Plastic Yielding: A Finite Deformation Embedded Singularity, Elastoplastic Incremental Finite-Element Solution—s. N. ATLURI,

MICHIHIKO NAKAOAKI, AND WEN-HWA CHEN 4 2

Brief Description of Formulation 44 Problem Definition 52 Results for J-Integral 53 Conclusions 60

Comparison of Compliance and Estimation Procedures for Calculating J-Integral Values—j. p. HICKERSON, JR. 62

Procedures 65 Results and Discussion 68 Conclusions 70

Evaluation of the Toughness of Tliick Medium-Strength Steels by Using Linear-Elastic Fracture Mechanics and Correlations Between Ki^ and Charpy V-Notch—B. MARANDET AND G. SANZ 72

Steels Studied—Heat Treatments 73 Experimental Results 78 Correlations Between ATje and Other Brittleness Parameters 88 Conclusions 94

Correlation Between the Fatigue-Crack Initiation at the Root of a Notch and Low-Cycle Fatigue Data—A. BAUS, H. P. LIEURADE,

G. SANZ, AND M. TRUCHON 9 6 Materials 97 Experiments 98 Results of Initiation Tests 99 Behavior of Metal at Notch Root 101 Calculation of the Duration of the Initiation Phase 107 Comparison of Different Analyses 108 Conclusions 109

Ductile Rupture Blunt-Notch Fracture Criterion—j. A. BEGLEY,

w. A. LOGSDON, AND J. D. LANDES 112

Experimental Procedures 113 Results 116 Discussion 119 Summary and Conclusions 119

Stress-Corrosion Crack Initiation in High-Strength Type 4340 Steel—W. G. CLARK, JR. 121

Material and Specimen Preparation 123 Experimental Procedure 124 Analysis of Blunt-Notch Specimens 126 Experimental Results 128 Discussion 133 Summary and Conclusions 136

Fatigue-Crack Growth Rate Testing at Higli Stress Intensities— N. E. DOWLING 139

Laboratory Investigation 140 Discussion 148 Conclusions 155

Fatigue-Cracli Propagation in Electroslag Weldments—B. M. KAPADIA AND E. J. IMHOF, JR. 159

Materials and Experimental Procedure 160 Results and Discussion 164 Summary 172

Fatigue Growtli of Surface Craclcs—T. A. CRUSE, G. J. MEYERS, AND R. B. WILSON 174

Surface Flaw Specimen Correlation 175 Corner Crack Specimen Correlation 182 Conclusions 188

Stress Intensities for Craclis Emanating from Pin-Loaded Holes— C. W. SMITH, M. JOLLES, AND W. H. PETERS 190

Analytical Considerations 191 Conclusions 200

Dependence of /i^ <>n tlie Meclianical Properties of Ductile Materials—j. LANTEIGNE, M. N. BASSIM, AND D. R. HAY 202

J-Integral as a Function of Compliance 203 Plastic Zone Correction 205 Dependence of 7,̂ on the Mechanical Properties 207 Experimental Results 208 Discussion 213 Summary and Conclusions 215

Effect of Specimen Size on J-Integral and Stress-Intensity Factor at the Onset of Crack Extension—H. P. KELLER AND D. MUNZ 217

General Remarks on the Effect of Specimen Size 218 Materials and Experimental Procedure 221 Experimental Results 223 Conclusions 229

Determination of Stress Intensities of Through-Cracks in a Plate Structure Under Uncertain Boundary Conditions by Means of Strain Gages—H. KITAGAWA AND H. ISHIKAWA 232

Procedures of Analysis 233 Calculating Table for Stress-Intensity Factors 238 Examination of Accuracy of the Present Calculation 238 Examples of Determination of K by the Experiments of Strain

Measurement and Examination of Availability of the Present Method 241

Summary 242

Determination of R-Curves for Structural Materials by Using Nonlinear Mechanics Methods—D. E. MCCABE 245

Specimen 247 Equipment 247 Cryogenic Tests 251 Instrumentation 252 Test Procedure 254 Summary and Discussion 263

Fracture Behavior of Bridge Steels—R. ROBERTS, G. V. KRISHNA,

AND G. R. IRWIN 267

General Fracture Behavior of Structural Steels 268 Experimental Details 270 Experimental Results 274 AASHTO Requirements and Fracture Safe Bridge Design 281

Fracture Characteristics of Plain and Welded 3-In.-Thick Aluminum Alloy Plate at Various Temperatures—F. G. NELSON AND D. J. BROWNHILL 285

Material 286 Procedure 288 Discussion of Results 293 Conclusions 306

Fracture Toughness of Random Glass Fiber Epoxy Composites: An Experimental Investigation—SATISH GAGGAR AND L. J. BROUTMAN 3 1 0

Material Preparation and Experimental Procedure 311 Results and Discussion 312 Conclusion 329

Effect of Cold Working on Kj^ in a 4340 Steel—w. G. CLARK, JR. 331 Material and Specimen Preparation 332 Experimental Procedure 334 Experimental Results 335 Discussion 342 Conclusions 343

Corrosion Fatigue Properties of Ti-6Al-6V-2Sn (STOA)— W. E. KRUPP, J. T. RYDER, D. E. PETTIT, AND D. W. HOEPPNER 345

Material Characterization 346 Fatigue Crack Propagation Test Procedure 348 Results 351 Discussion 359 Conclusions 362

Effect of Thickness on Retardation Behavior of 7074 and 2024 Aluminum Alloys—G. R. CHANANI 365

Experimental Procedure 366 Results and Discussion 367 Summary and Conclusions 385

Spectrum Loading—A Useful Tool to Screen Effects of Microstructure on Fatigue Crack-Growth Resistance— R. J. Bucci 388

Fatigue-Crack Propagation Through a Measured Residual Stress Field in Alloy Steel—j. H. UNDERWOOD, L. P. POCK, AND

J. K. SHARPLES 4 0 2

Test Procedures 404 Test Results and Analysis 407 Closing 414

Automated Design of Stiffened Panels Against Crack Growth and Fracture Among Other Design Constraints—c. s. DA vis 416 Crack Growth and Fracture 419 Automated Design Procedure 431 Design Problems and Results 432 Conclusions 442

Evaluation of Current Procedures for Dynamic Fracture-Toughness Testing—w. L. SERVER, R. A. WULLAERT, AND J. W. SHECKHERD 446

Material and Specimen Preparation 447 Testing Equipment 448 Discussion of EPRI Dynamic Test Procedures 448 Results 451 Conclusions and Recommendations 456

Experimental Verification of the / , , and Equivalent Energy Methods for the Evaluation of the Fracture Toughness of Steels—B. MARANDET AND G. SANZ 4 6 2

Materials and Experimental Methods 463 Experimental Results 469 Application of the Equivalent Energy Method 473 Conclusions 474

Dynamic Fracture Toughness of SA533 Grade A Class 2 Base Plate and Weldments—w. A. LOGSDON AND J. A. BEGLEY 477

Material, Mechanical Properties, and Weld Parameters 478 Experimental Procedures 482 Results 486 Discussion 489 Conclusions 491

Prediction of Fracture Toughness K^^ of 2 ViCr-lMo Pressure Vessel Steels for Charpy V-Notch Test Results—T. IWADATE,

T. KARAUSHI, AND J. WATANABE 4 9 3

Materials and Experimental Procedure 494 Results and Discussion 498 Summary 504

Analysis of Stable and Catastrophic Crack Growth Under Rising Load—s. R. VARANASI 507

Finite Element Analysis 508 Results 511 Concluding Remarks 518