When a crack is lodged in an inclusion, the difference between the elastic modulus of the inclusion and matrix material will cause the near-tip stress intensity factor to be greater or less than that prevailing in a homogeneous material. A method is derived for calculation of the near-tip stress intensity factor for the inclusion with arbitrary shape. The derivation of the fundamental formula is based on the transformation toughening theory. The equivalent transformation strain contributed from modulus difference between inclusion and matrix is calculated from Eshelby equivalent inclusion approach. As validated by numerical examples, the developed formula has excellent accuracy.

1.
Hutchinson
,
J. C.
,
1987
, “
Crack Tip Shielding by Micro-Cracking in Brittle Solids
,”
Acta Metall.
,
35
, pp.
1605
1619
.
2.
Steif
,
P. S.
,
1987
, “
A Semi-Infinite Crack Partially Penetrating a Circular Inclusion
,”
ASME J. Appl. Mech.
,
54
, pp.
87
92
.
3.
Erdogan
,
F.
, and
Gaupta
,
G. D.
,
1975
, “
The Inclusion Problem With a Crack Crossing the Boundary
,”
Int. J. Fract.
,
11
, pp.
13
27
.
4.
Li
,
R.
, and
Chudnovsky
,
A.
,
1993
, “
Energy Analysis of Crack Interaction With an Elastic Inclusion
,”
Int. J. Fract.
,
63
, pp.
247
261
.
5.
Evans
,
A. G.
, and
Faber
,
K. T.
,
1981
, “
Toughening of Ceramics by Circumferential Microcracking
,”
J. Am. Ceram. Soc.
,
64
, pp.
394
398
.
6.
McMeeking
,
R. M.
, and
Evans
,
A. G.
,
1982
, “
Mechanics of Transformation Toughening in Bittle Materials
,”
J. Am. Ceram. Soc.
,
65
, pp.
242
246
.
7.
Eshelby
,
J. D.
,
1957
, “
The Determination of the Elastic Fields of an Ellipsoidal Inclusion, and Related Problems
,”
Proc. R. Soc. London, Ser. A
,
241
, pp.
376
396
.
8.
Withers
,
D. J.
,
Stobbs
,
W. M.
, and
Pedersen
,
O. B.
,
1989
, “
The Application of the Eshelby Method of Internal Stress Determination to Short Fibre Metal Matrix Composites
,”
Acta Metall.
,
37
, pp.
3061
3084
.
9.
Moschobidis
,
Z. A.
, and
Mura
,
T.
,
1975
, “
Two Ellipsoidal Inhomegeneities by the Equivalent Inclusion Method
,”
ASME J. Appl. Mech.
,
42
, pp.
847
852
.
10.
Taya
,
M.
, and
Chou
,
T. W.
,
1981
, “
On Two Kinds Ellipsoidal Inhomegeneities in an Infinite Elastic Body: An Application to a Hybrid Composites
,”
Int. J. Solids Struct.
,
17
, pp.
553
563
.
11.
Johnson
,
W. C.
,
Earmme
,
Y. Y.
, and
Lee
,
J. K.
,
1980
, “
Approximation of the Strain Field Associated With an Inhomegeneous Pricipitate
,”
ASME J. Appl. Mech.
,
47
, pp.
775
780
.
12.
Lambropoulos
,
J. C.
,
1986
, “
Shear, Shape and Orientation Effects in Transformation Toughening in Ceramics
,”
Int. J. Solids Struct.
,
22
, pp.
1083
1106
.
13.
Budiansky
,
B.
,
Hutchinson
,
J. W.
, and
Lambropoulos
,
J. C.
,
1983
, “
Continuum Theory of Dilatant Transformation Toughening in Ceramics
,”
Int. J. Solids Struct.
,
19
, pp.
337
355
.
14.
Mura, T., 1987, Micromechanics of Defects in Solids, Second Rev. Ed., Kluwer, Dordrecht, The Netherlands.
You do not currently have access to this content.