STP 1074 Fracture Mechanics: Twenty-First Symposium J P Gudas, J A Joyce, and E M Hackett, editors AsTM 19 l Race Street Philadelphia, PA 19103 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorize ASTM Publication Code Number (PCN): 04-010740-30 ISBN: 0-8031-1299-8 ISSN: 1040-3094 Copyright © 1990 by the American Society for Testing and Materials All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher NOTE The Society is not responsible, as a body, for the statements and opinions advanced in this publication 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 technical editor(s) and the ASTM Committee on Publications 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 dedication and contribution of time and effort on behalf of ASTM Pnnted m Baltimore, Md August 1990 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized Foreword The ASTM Twenty-First National Symposium on Fracture Mechanics was held in Annapolis, Maryland, on 28-30 June 1988 Its sponsor was Committee E-24 on Fracture Testing The co-chairmen for this symposium were John P Gudas, David Taylor Research Center; James A Joyce, United States Naval Academy; and Edwin M Hackett, David Taylor Research Center They have also served as editors of this volume Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions Contents ix Introduction ELASTIC-PLASTIC FRACTURE MECHANICS (I) An Analytical Comparison of Short Crack and Deep Crack C r O D Fracture Specimens of an A36 Steel w.A SOREM, R H DODDS,JR., ANDS T ROLFE Direct J-R Curve Analysis: A Guide to the Methodology R HERRERAAND 24 J D LANDES Application of the Method of Caustics to J-Testing with Standard Specimen Geometries R J SANFORD AND R W JUDY, JR 44 Extrapolation of C(T) Specimen J-R Curves G M WILKOWSKI,C W MARSCHALL, 56 AND M P LANDOW Application of J-Integral and Modified J-Integral to Cases of Large Crack Extension J A JOYCE, D A DAVIS, E M HACKETT, AND R A HAYS 85 DYNAMIC FRACTURE Impact Fracture of a Tough Ductile Steel A s DOUGLASANDM S SUH 109 Dynamic Fracture Behavior of a Structural Steel K CliO, J P SKLENAK,AND 126 143 J DUFFY Discussion Dynamic Key-Curves for Brittle Fracture Impact Tests and Establishment of a Transition T i m e - - w BOHME 144 Explosive Testing of Full Thickness Precracked Weldments L N GI~ORD, J R CARLBERG, A J WIGGS, AND J B SICKLES Magnetic Emission Detection of Crack Iuitiation s R WINKLER 157 178 TRANSITION FRACTURE Effect of Biaxial Loading on A533B in Ductile-Brittle Transition s J CARWOOD, T G DAVEY, AND Y C WONG 195 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized Fracture Toughness in the Transition Regime for A533B-I Steel: The Effect of Specimen Sidegrooving E MORLAND 215 Analysis of Fracture Toughness Data for Modified SA508 C12 in the Ductile-toBrittle Transition Region M T MIGLIN,C S WADE,AND W A VANDER SLUYS Discussion 238 263 Effects of Warm Pre-Stressing on the Transition Toughness Behavior of an A533 Grade B Class Pressure Vessel Steel r) LIDBURYANDP BIRKETT 264 ELASTIC-PLASTIC FRACTURE MECHANICS (II) Unique Elastic-Plastic R-Curves: Fact or Fiction? M R ETEMADAND 289 C E TURNER Adhesive Fracture Testing M F MECKLENBURG, C O ARAH, D McNAMARA, 307 319 H HAND, AND J A JOYCE Discussion Evaluation of Elastic-Plastic Surface Flaw Behavior and Related Parameters Using Surface Displacement Measurements w R LLOYDAND 322 W G REUTER MICROMECHANICS OF FRACTURE Effect of Dynamic Strain Aging on Fracture Resistance of Carbon Steels Operating at Light-Water Reactor Temperatures c w MARSCHALL, M P LANDOW, AND G M WILKOWSKI 339 Prediction of Fracture Toughness by Local Fracture Criterion T MIYATA, A OTSUKA~ M MITSUBAYASHI, T HAZE, AND S AIHARA 361 Microscopic Aspects of Ductile Tearing Resistance in AISI Type 303 Stainless S t e e l - - A SAXENA, D C DALY, H A ERNST, AND K BANE1LII Microstructure and Fracture Toughness of Cast and Forged Ultra-High-Strength, Low-Alloy (UHSLA) Steels J ZEMAN, S ROLC, J BUCHAR, AND J POKLUDA 378 396 COMPUTATIONAL MECHANICS Simulation of Crack Growth and Crack Closure under Large Cyclic Plasticity-K S KIM, R H VAN STONE, J H LAFLEN, AND T W ORANGE 421 Comparison of Elastic-Plastic Fracture Mechanics Techniques F w BRUST, M NAKAGAKI, AND P GILLLES 448 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions autho Treatment of Singularities in a Middle-Crack Tension S p e c i m e n - K N SHIVAKUMAR AND I S RAJU Assessment of Influence Function for Elliptical Cracks Subjected to Uniform Tension and to Pure Bending M PORE 470 490 Finite Element Meshing Criteria for Crack Problems w n GERSTLEAND 509 J E ABDALLA, JR FRACTURE MECHANICS APPLICATIONS Application of the CEGB Failure Assessment Procedure, R6, to Surface F l a w s - 525 G G CHELL Method and Models for R-Curve Instability Calculations T w ORANGE 545 FRACTURE MECHANICS TESTING Closure Measurements via a Generalized Threshold Concept -G MARCI, D E CASTRO, AND V BACHMANN 563 Use of the Direct-Current Electric Potential Method to Monitor Large Amounts of Crack Growth in Highly Ductile Metals c w MARSCHALL,P R HELD, M P LANDOW, AND P N MINCER 581 Load-Point Compliance for the Arc-Bend/Arc-Support Fracture Toughness Specimen F I BARATTA, J A KAPP, AND D S SAUNDERS 594 Author Index 613 Subject Index 615 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized Introduction The success of the Twenty-First National Symposium on Fracture Mechanics, held on 28-30 June 1988 in Annapolis, Maryland, and sponsored by ASTM Committee E-24 on Fracture Testing, demonstrated the continued rapid development occurring in this field Papers were solicited from all areas of fracture mechanics and its applications Contributions representing a wide range of topics came from the United States and six foreign countries New work is presented in elastic-plastic fracture, dynamic fracture, transition fracture in steels, micromechanical aspects of the fracture process, computational mechanics, fracture mechanics testing, and applications of this technology Each area poses its own challenges, and developments proceed somewhat independently This volume aids the researcher in keeping abreast of these varied aspects of the discipline of fracture mechanics The diligent work of the Symposium Organizing Committee, the authors, and the reviewers is gratefully appreciated We would particularly like to recognize the efforts of the ASTM staff including Mr Hans Greene, Ms Kathy Friend, Ms Wendy Dyer, Ms Kathy Greene, Ms Monica Armata, Ms Rita Harhut, and Mr Allan Kleinberg Finally, the assistance of Mrs Mary Cropley and Ms Amanda Ewen of the David Taylor Research Center is gratefully acknowledged J P Gudas J A Joyce E M Hackett Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions Elastic-Plastic Fracture Mechanics (I) Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized IV A Sorem, ~R H Dodds, Jr., and S T Rolf8 An Analytical Comparison of Short Crack and Deep Crack CTOD Fracture Specimens of an A36 Steel REFERENCE: Sorem, W A., Dodds, R H., Jr., and Rolfe, S T., "An Analytical Comparison of Short Crack and Deep Crack CTOD Fracture Specimens of an A36 Steel," Fracture Mechanics: Twenty-First Symposium, ASTM STP 1074, J P Gudas, J A Joyce, and E M Hackett, Eds., American Society for Testing and Materials, Philadelphia, 1990, pp 3-23 ABSTRACT: The effect of crack-depth to specimen-width ratio on crack tip opening displacement (CTOD) fracture toughness is an important consideration in relating the results of laboratory tests to the behavior of actual structures Deeply cracked three-point bend specimens with crack-depth to specimen-width ratios (a/W) of 0.50 are most often used in laboratory tests However, to evaluate specific weld microstructures or the behavior of structures with shallow surface cracks, specimens with a~W ratios much less than 0.50 often are required Laboratory tests reveal that three-point bend specimens with short cracks (a/W = 0.15) exhibit significantly larger critical CTOD values than specimens with deep cracks (a/W = 0.5) up to the point of ductile initiation In this study, finite element analyses are employed to compare the elastic-plastic behavior of square (cross-section) three-point bend specimens with crack-depth to specimen-width ratios (a/W) ranging between 0.50 and 0.05 The two-dimensional analysis of the specimen with an a/Wratio of0.15 reveals a fundamental change in the deformation pattern from the deep crack deformation pattern The plastic zone extends to the free surface behind the crack concurrent with the development of a plastic hinge For shorter cracks (a/W = l0 and 0.05), the plastic zone extends to the free surface behind the crack pnor to the development of a plastic hinge For longer cracks (a/W > 0.20), a plastic hinge develops before the plastic zone extends to the free surface behind the crack These results prompted further study of specimens with an a/W ratio of 0.15 using threedimensional, elastic-plastic finite element analyses Results of the short crack (a/W = 0.15) analysis are compared to the results of the deep crack (a/W = 0.50) analysis reported previously by the authors In the linear-elastic regime (characterized by small-scale plastic deformation) the relationship of stress ahead of the crack tip to CTOD is identical for the short crack and the deep crack specimens At identical CTOD levels in the elastic-plastic regime (largescale plasticity, hinge formation), the crack tip stress is significantly lower for specimens with a~W = 0.15 than for specimens with a~W = 0.50 Correspondingly, at equivalent stress levels, the CTOD for the short crack is approximately 2.5 times the CTOD for the deep crack This observation has considerable significance in the application of CTOD results to failure analysis or specification development where the fracture mechanism is cleavage preceded by significant crack tip plasticity KEY WORDS: elastic-plastm fracture mechanics, CTOD, crack depth, short crack, toughness, finite element, constraint University of Kansas, Lawrence, KS 66045; currently at Exxon Production Research Company, Houston, TX 77252 University of Illinois, Urbana, IL 61801 University of Kansas, Lawrence, KS 66045 Copyright9 1990by ASTM International www.astm.org Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized BARATTA ET AL ON ARC-BEND/ARC-SUPPORT SPECIMEN 605 t~ N C- N r'F- D ~ r ~ I II II II ~ s ~_ N-~ II ~-~ II X sd ILl ~ H"' H E H,~, H,~ ~ ~ ~ ~ T2 ~-~ C ~ I [] ,~ , IIIIIII I I IIIIIIII I IHIII iii ~IJJIILIIIJ I llliiiiI -~',,dll~JI I 1111111 ~],1!!!!! ! ! IIII IIIII I k0~ll !1111II ~ !1~11 0 0 c- IIIIII I1!! "I:D I IIIii r~l 0 0 c d d "r= d d d ~.-~ d ('xl d d O O ~1~ Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized 606 FRACTURE MECHANICS: TWENTY-FIRST SYMPOSIUM L , o N (~ N ~ ~:~ x2 ~ I-'- ~-g ~-E ~E , ~ ,q- g ,'i- I I " I m o [] II ~,!11 IIII IIIIII II IIitl II o 0 ~ III i ! O % o I~1\1111 I1 ~1111 0 0 o ~% O o ~ o ~ 0 Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions authorized BARATTA ET AL ON ARC-BEND CARC-SUPPORT SPECIMEN 607 5000 V/ 3000 Load (Pounds) 2000 1000 / 0.0 / / J // J // 4000 I /, ( I // IX/ Y/ I//I Y /A // V~ I// / 2.0 4.0 6.0 8.0 0.0 12.0 Displacement (Thounsandth's of an Inch) FIG Typical load-line displacement versus appfied load traces when using the experimental arrangement for three-point bending samples suggested m A S T M E 399 The radius ratio was 2.0, Oowas 36*, and the normalized crack lengths were (from left to rlgh 0.35, 0.45, and 0.55 The discrepancy in the K solutions with modeling is also very confusing As stated the two models for the specimen are statically equivalent Therefore the stresses produced by either loading condition should be the same Of the three specimen parameters reported in this paper, K should be the parameter most closely associated with stress Therefore it would be expected that the parameter most insensitive to modeling should be K This is apparently not the case A possible explanation is that the additional displacement introduced by the idealized boundary conditions would cause the resultant bending stress on the uncracked ligament to change If the stress on the uncracked ligament changes, certainly the stress intensity factor would change Experimental Procedure Experimental measurements of load-line compliances for the arc-bend/arc-support sample in several possible specimen geometries were obtained Two sets of experiments were run In the first, as shown in Fig 3, great pains were taken to position the fixtures of the reaction rollers The rollers were fixed in space, but were supported in bearings such that free rotation of the supports was allowed Although not shown in Fig 3, the columns supporting the rollers and bearings were stiffened during testing in the horizontal direction to minimize lateral deflection of the fixture In the second study, the rollers were positioned as suggested in ASTM E 399 In this second case, the rollers are fixed so that they cannot move in the direction of the applied load, but are free to move perpendicular to the direction of the applied load This is another way to accommodate rotation of the roller supports Also, in the first study cracks were approximated by machined saw cuts or by fatigue cracking, while in the second group of experiments the cracks were produced by fatigue cracking only The material used in the first study was a brittle martensitic steel whose properties are presented in Copyright by ASTM Int'l (all rights reserved); Tue Dec 15 12:58:27 EST 2015 Downloaded/printed by University of Washington (University of Washington) pursuant to License Agreement No further reproductions auth 608 FRACTURE MECHANICS: TWENTY-FIRST SYMPOSIUM -~ o~ - ~'c E I N~ U 14- ~ E 14.1 O L.~ LO ,.O O L~ If) O L~ O O O Uh @