Previous studies have shown that there is an increase in cleavage fracture toughness of laboratory specimens with shallow flaws compared with those laboratory specimens having deep flaws. Typical crack depths in real structures generally are very small relative to the member width. Therefore, the crack depth to structural member width (a/W) ratios are very small (less than 0.1). Accordingly, the effect of this observation on the behavior of larger structures that actually represent typical engineering applications could be significant. Using experimental and analytical results from previous studies on A533-B steel specimens, the effect of the shallow flaw behavior with respect to very large specimens was examined. Using the Dodds and Anderson constraint correction, predictions of the cleavage fracture toughness of large-scale wide-plate tests and full thickness clad beams from an actual reactor pressure vessel were shown to compare favorably with actual test results. The results of these studies suggest the possibility of predicting the increase in fracture toughness for low constraint structural geometries using high-constraint laboratory test specimen results. The ability to take advantage of this increase in toughness in analysis of actual structures could be very useful in estimating the actual safety and reliability of existing structures with service cracks.

1.
ASME Boiler and Pressure Vessel Code, 1972, Section III, Nuclear Power Plant Components, ASME, New York, NY.
2.
ASME Boiler and Pressure Vessel Code, 1989, Section XI, Rules for Inservice Inspection of Nuclear Power Plant Componants, Appendix A, ASME, New York, NY.
3.
Anderson
T. L.
, and
Dodds
R. H.
,
1991
, “
Specimen Size Requirements for Fracture Toughness Testing in the Transition Region
,”
Journal of Testing and Evaluation
, JTEVA, Vol.
19
, No.
2
, pp.
123
134
.
4.
Anderson
T. L.
,
1989
, “
Crack Tip Parameters for Large Scale Yielding and Low Constraint Configurations
,”
International Journal of Fracture
, Vol.
41
, pp.
79
104
.
5.
ASTM, 1983, “Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials,” ASTM E399-83, American Society for Testing and Materials, Philadelphia, PA.
6.
ASTM, 1989, “Standard Test Method for JIc, a Measure of Fracture Toughness,” ASTM E813-89, American Society for Testing and Materials, Philadelphia, PA.
7.
Barsom, J. M., and Rolfe, S. T., 1987, Fracture and Fatigue Control in Structures, 2nd Edition, Prentice-Hall, Englewood Cliffs, NJ.
8.
Dodds, R. H., Jr., 1993, ASTM E08.08.04 meeting, Atlanta, GA.
9.
Dodds, R. H., Jr., 1994, “Constraint Effects on Fracture Initiation Loads in HSST Wide-Plate Tests,” a Report to the Heavy-Section Steel Technology Program Oak Ridge National Laboratory, SRSN 591, University of Illinois, Urbana, IL.
10.
Dodds
R. H.
,
Anderson
T. L.
, and
Kirk
M. T.
,
1991
, “
A Framework to Correlate a/W Ratio Effects on Elastic-Plastic Fracture Toughness (Jc)
,”
International Journal of Fracture
, Vol.
48
, pp.
1
22
.
11.
Keeney, J. A., Bass, B. R., McAfee, W. J., and Iskander, S. K., 1994, “Preliminary Assessment of the Fracture Behavior of Weld Material in Full-Thickness Clad Beams,” NUREG/CR-6228 ORNL/TM-12735, U.S. Nuclear Regulatory Commission, Washington, DC.
12.
Kirk, M. T., Koppenhoefer, K. C., and Shih, C. F., 1993, “Effects of Constraint on Specimen Dimensions Needed to Obtain Structurally Relevant Toughness Measures,” Constraint Effects in Fracture, E. M. Hackett, K. H. Schwalbe, and R. H. Dodds, eds., American Society for Testing and Materials, pp. 79–100.
13.
Koppenhoefer, K. C., and Dodds, R. H., 1995, “Size and Deformation Limits to Maintain Constraint in KIc and Jc Testing of Bend Specimens,” NUREG/CR-6191, U.S. Nuclear Regulatory Commission, Washington, DC.
14.
Link, R. E., and Joyce, J. A., 1994, “Experimental Investigation of Fracture Toughness Scaling Models,” Constaint Effects in Fracture: Theory and Applications, ASTM STP 1244, Mark Kirk and Ad Bakker, eds., American Society of Testing and Materials, Philadelphia, PA.
15.
Naus, D. J. et al., 1987, Martin Marietta Energy Systems, Inc., Oak Ridge National Lab., “Crack-Arrest Behavior in SEN Wide Plates of Quenched and Tempered A533 Grade B Steel Tested Under Nonisothermal Conditions,” USNRC Report NUREG/CR-4930 (ORNL/TM-6388).
16.
Neale
B. K.
,
Sherry
A. H.
, and
Wardle
G.
,
1994
, “
The Implications of Imposing the Anderson and Dodds Size Requirement in Fracture Toughness Testing Procedures
,”
Fatigue Fracture Engineering Material Structure
, Vol.
17
, No.
8
, pp.
931
938
.
17.
O’Dowd
N. P.
, and
Shih
C. F.
,
1991
, “
Family of Crack-Tip Fields Characterized By a Triaxiality Parameter: Part I—Structure of Fields
,”
Journal of Mechanics and Physics of Solids
, Vol.
39
, pp.
989
1015
.
18.
O’Dowd
N. P.
, and
Shih
C. F.
,
1992
, “
Family of Crack-Tip Fields Characterized By a Triaxiality Parameter: Part II—Fracture Applications
,”
Journal of Mechanics and Physics of Solids
, Vol.
40
, pp.
939
963
.
19.
PVRC Ad Hoc Group on Toughness Requirements, 1972, “PVRC Recommendations on Toughness Requirements for Ferritic Materials,” WRC Bulletin No.175.
20.
Smith, J. A., and Rolfe, S. T., 1994, “The Effect of Crack Depth (a) and Crack Depth to Width Ratio (a/W) on the Fracture Toughness of A533-B Steel,” ASME JOURNAL OF PRESSURE VESSEL TECHNOLOGY.
21.
Smith, J. A., and Rolfe, S. T., 1995, “An Analytical Study of the Effect of Crak Depth (a) and Crack-Depth to Width (a/W) Ratio on the Fracture Toughness of A533-B Steel,” presented at the 27th National Symposium on Fatigue and Fracture Mechanics, Williamsburg, VA; to be published in Fatigue and Fracture Mechanics: 27th Vol. ASTM STP 1296.
22.
Sorem, W. A., Dodds, R. H., Jr., and Rolfe, S. T., 1990, “An Analytical Comparison of Short and Deep Crack CTOD Fracture Specimens of an A36 Steel,” WRC Bulletin No. 351.
23.
Tang, M., Dodds, R. T., Jr., and Anderson, T. L., 1994, “Effects of Ductile Crack Growth on Constraint Models for Cleavage Fracture,” Report to the U.S. Nuclear Regulatory Commision Office of Nuclear Regulatory Research Division of Engineering, SRSN 585, University of Illinois, Urbana, IL.
24.
Theiss, T. J., Shum, D. K., and Rolfe, S. T., 1992, “Experimental and Analytical Investigation of the Shallow-Flaw Effect in Reactor Pressure Vessels,” NUREG/CR-5886 ORNL/TM-12115, U.S. Nuclear Regulatory Commission, Washington, DC.
25.
Wallin, K., 1993, “Statistical Aspects of Constraint With Emphasis on Testing and Analysis of Laboratory Specimens in the Transition Region,” Constraint Effects in Fracture, ASTM STP 1171, E. M. Hackett, K. H. Schwalbe, and R. H. Dodds, eds., American Society of Testing and Materials, pp. 264–288.
26.
Wallin
K.
,
1995
, “
The Size Effect in KIc Results
,”
Engineering Fracture Mechanics
, Vol.
22
, No.
1
, pp.
149
163
.
27.
Whorley, R. A., and Rolfe, S. T., 1993, “The Significance of the a/W ratio on Fracture Toughness of A36 Steel,” WRC Bulletin No. 375.
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