Crack Paths 2006

coefficient, respectively). The plate and crack sizes are:

m m 3.1240 120u u tu hu b ,

initial crack length

6 cm

with different values of the initial orientation

0 a

), measured with respect to the loading direction (Fig. 3a).

(

º90,º45,º30

0 T

From the experimental results, it can be deduced that the environmental temperature

does not heavily influence the crack paths, independent of the initial crack orientation

value, but the failure mode changes from brittle- (for T = -20 ºC) to ductile-type (for T =

+80 ºC). As an example, crack paths for

º30

are shown in Fig. 4a to c.

0 T

actuator

loading direction

link device

specimen holder (rigid)

existing pre-crack

T

0

specimen

a

h

0

C O D

b

link device

load cell

(a)

(b)

Figure 3. Experimental set-up.

(b)

(a)

(c)

Figure 4. Crack paths and final collapsed configurations for aluminium plates with an initial

crack having

º30

, in the case of T equal to : (a) Cº20 , (b) Cº20 , (c) Cº80 .

0 T