Fatigue Crack Paths 2003

1 2

Cotterell csutarbvl d

1680

unstable

curved

024

Present Work

stable

straight

0

0.2

0.4

0.6

0.8

1

a/w

Figure 4. Classification map of crack path (in)stability

for TPB-type specimen.

Figure 5 shows the S E Dcontours for the D C Bspecimen having W=15cm,h=1.5cm and

a=1.5cm. This gives a/W=0.1 and h/W=0.1. The path O Gcorresponds to the stable

curved crack trajectory that falls to the region further to the left in Fig. 4. The case of

straight and stable crack is predicted in Figure 6 where a/W= 0.80 and h/W= 0.53.

This falls into the right region in Figure 4.

Figure 5. Contours map of (dW/dV) and crack path O Gin DCB-type specimen with

a/W=0.1 and h/W=0.1.