Fatigue Crack Paths 2003

crack, starting from welded joint, propagates firstly in mode II and then, by a crack path

deviation realised in a kinking or branching, switches to modeI propagation.

As the starting mode of propagation is mode II, it would be important to analyse the

influence of the position of the welded joint in the rail on the variation of ΔKII. In all the

cases considered here, the weld were always at the middle between two sleepers.

Furthermore, it would be important to analyse crack grow rate, in order to define the

inspection intervals for welded rails.

160

KI

final kinking

140

KII

120

100

80

60

40

20

0

-100

-50

0

50

100

αα[degree]

Figure 9. Leading tip at Step 3: Variation of KI and KII with the kink angle (the final

1.

kinking angle maximises KI).

2.

R E F E R E N C E S

3.

Kondo, K., Yoroizaka, K. and Sato, Y.(1996) Wear 191, 199-203.

4.

Ishida, M. and Abe, N. (1996) Wear 191, 65-71.

Akama, M. and Mori, T. (2002) Wear 253, 35-41.

5.

Bold, P.E., Brown, M.W.and Allen, R.J. (1991) Wear 144, 307-317.

Bogdanski, S. and Brown, M. W. (2002) Wear 253, 17-25.

6.

Jung-Kyu, Kimand Chul-Su, Kim(2002) Materials Science and Engineering A338,

7.

191-201.

Melin, S. (1986) Int. Journal ofFract 30, 103-114.

8.

Wong,S.L, Bold, P.E., Brown, M.W.and Allen, R.J. (1996) Wear 191, 45-53.

9. Murakami, Y. and Takahashi, K. (1998) Fatigue Fract. Engng Mater Struct 17,

201-219.

10.

Murakami, Y, Sakae, C. and Hamada, S. (1999) In: Fracture, pp.473-485, Beynon,

J.H. (Ed.), Balkema, Rotterdam.

11.

A S MMetal Handbook (1997) Ninth Edition, Vol 12, Fractography.

12.

A S MHandbook (1996) Vol 19, Fatigue and Fracture.

13.

A B A Q U(S2000) User’s Manual. Hibbit, Karlsson & Sorensen Inc.

14. Anderson, T.L (1995) Fracture Mechanics, C R CPress, Boca Raton.