Crack Paths 2012

1 (1+ 21 i 4v)cos(1—7t1)0+ X1 (1 —7t1)cos(1 + ltl)0

(i) 9 :

f1

2 % 1‘1'7\'1‘1'X1(1_7"1)

(12)

f(._.)(e)_

l (1+7»2 i4v)sin(l—7\.2)0+X2(1+7\.2)sin(1+7t2)0

2

2 m 1—7t2+X2(1+7t2)

and 7t, [13, 14] are the eigenvalues of the V-notchproblem, while X, are coefficients

dependent on the notch angle [15].

40

300

mOK[K[-4O594O]9M,]Pa12

3 0 '

. 0

0.3K[3M3]Pmam3

_ F < —60

7 % ? ; — > F .0.‘ 1 2 0 0

.‘i

1

20

2 0 _

. Q . \ K 3

1

'

' M 100 1 o o o o o 0 o G O O O O O o O O o O O O O o O O O O Q O

O

6

10

K2

0

|

|

|

I

l

|

|

I

l

l

l

I

l

|

|

l

|

|

l

0

0

0.2

0.4

0.6

0.8

l

2z/t

Figure 6. Plot of Ki along the thickness for a shouldered plate with t:80 m m .

Due to the assumption that the crack initiation growth direction is perpendicular to

01, the angles of crack initiation, 00 and 010, can be determined from the following

conditions:

8261

n _

2

< 0

(13)

a 9 9 : 9 0

9 : 9

and:

l - 2K3 13-1 (V0 = 5 A r gKlr f1 ( % ) - K g 2 ( G O ) + Z E I00501090 7.1-1 (—) >~.—1 (—)

(14)

It is evident from Eq. (13) and (14) that the angles 0* and 01* are independent of the

distance from the notch tip only for the crack case (71127122713205).

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