Crack Paths 2006

2500

]

0.5

2000

Pa m m

[M

1500

v a l u e o f S I F

no-web

1000

middle-web

a x i m u m

end-web

50

500 0

100

150

200

M

Area of initial crack:

2

1 8,16286,0mm A ˜

Crack area [mm2]

Figure 5. MaximummodeI stress intensity factor at crack fronts versus crack area.

Figure 6 shows the extended crack geometry after nine steps of simulation for two

various web arrangements. For design without web and the middle-web is resemblance

between them. The maximumextension occurred in the middle of crack front (Figure

6a). The crack growth is quite uniform. Predicted failure mode is a tooth breakage. For

case with end-web it is evidently that crack propagates non-symmetric with maximum

extension at web side (Figure 6b). From this it is clear that this design can lead to rim

breakage at non web side.

a) Middle-web

b) End-web

Figure 6. Simulated crack propagation paths for various web arrangements.