The effect of the interaction of multiple flaws on ductile fracture is studied numerically by Gurson’s constitutive equation. Based on experimental results, two parallel flaw and three parallel flaw problems are simulated. Flaw coalescence does not occur in some problems but does occur in other cases. In all cases, ductile fracture processes are obtained, and the results are compared with the experimental results. The fracture pattern and load-displacement curves agree well with the experimental results. The void growth term is found to be dominant for the coalescence of flaws. The slant flaw problem and the nonuniform length flaw problem are simulated and an evaluation method for the multiple flaws problem is discussed.

References

1.
Erdogan
,
F.
, and
Sih
,
G. C.
, 1963, “
On the Crack Extension in Plates Under Plane Loading and Transverse Shear
,”
ASME J. Basic Eng.
,
85
, pp.
519
527
.
2.
Yates
,
J. R.
, 1991, “
Fatigue Threshold Under Mixed-Mode (I + III)Loading
,”
Int. J. Fatigue
,
13
(
5
), pp.
383
388
.
3.
Pook
,
L. P.
, 1985, “
The Fatigue Crack Direction and Threshold Behavior of Mild Steel Under Mixed Mode I and III Loading
,”
Int. J. Fatigue
,
7
(
1
), pp.
21
30
.
4.
Kishimoto
,
K.
,
Aoki
,
S.
, and
Takeuchi
,
N.
, 1992, “
An Elastic-Plastic Finite Element Analysis of a Blunting Interface Crack With Micro Void Damage
,”
Int. J. Fract.
,
55
, pp.
363
374
.
5.
Tohgo
,
K.
, and
Ishii
,
H.
, 1992, “
Elastic-Plastic Fracture Toughness Test Under Mixed Mode I-II Loading
,”
Eng. Fract. Mech.
,
41
(4), pp.
529
540
.
6.
Kikuchi
,
M.
, and
Sannoumaru
,
S.
, 2007, “
Study on the Ductile Fracture Including the Shear-Lip Fracture
,”
Trans. Jpn. Soc. Mech. Eng. A
,
73
(
732
), pp.
98
105
(in Japanese).
7.
Kikuchi
,
M.
, and
Sannoumaru
,
S.
, 2008, “
Study on the Ductile Fracture Under Mixed Mode Loading Condition
,”
Trans. Jpn. Soc. Mech. Eng. A
,
74
(
745
), pp.
1235
1241
(in Japanese).
8.
Kikuchi
,
M.
, and
Sannoumaru
,
S.
, 2009, “
Study on the Ductile Fracture Under Mixed Mode Loading Condition: 2nd Report, Effect of Specimen Thickness
,”
Trans. Jpn. Soc. Mech. Eng. A
,
75
(
751
), pp.
353
359
(in Japanese).
9.
Gurson
,
A. L.
, 1977, “
Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part I—Yield Criteria and Flaw Rules for Porous Ductile Media
,”
ASME J. Eng. Mater. Technol.
,
99
, pp.
2
15
.
10.
Tvergaard
,
V.
, 1988, “
3D-Analysis of Localization Failure in a Ductile Material Containing Two Size-Scales of Spherical Particles
,”
Eng. Fract. Mech.
,
31
, pp.
421
436
.
11.
JSME S Nal-2004, “Codes for Nuclear Power Generation Facilities,” 2004 (in Japanese).
12.
Miyazaki
,
K.
,
Saito
,
K.
,
Hasegawa
,
K.
, and
Bezensek
,
B.
, 2009, “
Experimental Study of Ductile Fracture for Non-Aligned Multiple Flaws in a Plate
,” 2009 ASME Pressure Vessels and Piping Division Conference, PVP2009-77103.
13.
Hasegawa
,
K.
,
Saito
,
K.
,
Miyazaki
,
K.
, and
Bezensek
,
B.
, 2009, “
Evaluation of Alignment Rules Using Stainless Steel Pipes With Non-Aligned Flaws
,” 2009 ASME Pressure Vessels and Piping Division Conference, PVP2009-77068.
14.
Ghosal
,
A. K.
, and
Narasimhan
,
R.
, 1996, “
Numerical Simulations of Hole Growth and Ductile Fracture Initiation Under Mixed-Mode Loading
,”
Int. J. Fract.
,
77
, pp.
281
304
.
15.
Betegon
,
C.
,
Rodriguez
,
C.
, and
Belzunce
,
F. J.
, 1997, “
Analysis and Modelisation of Short Crack Growth by Ductile Fracture Micromechanisms
,”
Fatigue Fract. Eng. Mater. Struct.
,
20
(
5
), pp.
633
644
.
16.
Chu
,
C. C.
, and
Needleman
,
A.
, 1980,
Void Nucleation Effects in Biaxially Stretched Sheets
,”
ASME J. Eng. Mater. Technol.
,
102
, pp.
249
256
.
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