Crack Paths 2009

modeI into mixed mode crack, the double peak residual stress aggregates crack growth

in modeII.

45 0

2.8-40-weld

2.8-40-noweld

3 0

2 0

1 0

0

0 10 2 0 30 40 50 60 70 80 90 1 0 0 1 1 0 1 2 0 1 3 0 140 1 5 0 1 6 0

-10

-20

-30

-40

-50

Fig 7 The effect of weld on crack path with the hole

2.2.2 The Effect of Pad-up Parameter on Crack Growth Rate and Crack Path

For different pad-up size welded samples, crack growth rates of effective

I a were

compared with each other and parent material in Fig. 8. Compared with crack growth

rates shown in Fig3, crack growth rates increase for all samples and the effect of pad-up

sizes become smaller. Even this, the effect of pad-up thickness still can be pointed out:

crack grows slower with thin pad-up (2.2mmx40mm) than thick pad-up

(2.8mmx40mm),similar to the results without the hole on. Crack paths of different pad

up size were distributed in Fig. 9.

1.00E-09876543 1

10

100

2.8-40-hole-weld

2.8-20-hole-weld

2.2-40-hole-weld 198-Parent Material

deltk-I (MPam^0.5)

Fig 8 Crack growth rates versus

K  for the different pad-up sizes

660