Crack Paths 2009

1 0 x= +x x ∑ ,

y y y = + ∑ 0 1

and so on. For the central crack geometry subjected to

biaxial loads ( Fig.1,b) the crack path can be determined using the formulae [1]

( ) θ − π

β β =

[

]

()θ−π ∗

 

0 1 a +a − 2

0 0 20 2 c o s r a r

0 sinr a r c s i n . (3) 0

,

0 2 1

1

0

∗

=

a



1

Experimental data

Compact tension shear specimens (CTS) are made from a 30Cr steel and used for

0 = ÷

o o 9 0 0

to the

mixed-mode fracture test with the loading direction to an angle β

initial crack plane. Eight-petal specimens (EPS) are made from aluminum alloys and

η = 05.. The inclined angle

used for mixed-mode fracture test under biaxial stress ratio

β0 of initial crack, , was varied from 0° up to 90°.

Figure 2. Experimental crack paths for compact tension shear and eight-petal specimens

Figure 3. Comparison theoretical (curves) and experimental (points) crack paths for

mixed mode loading (a) compact tension shear specimen, (b,c) eight-petal specimen.

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