Biomedical Engineering Reference
In-Depth Information
Table 23.1
Material
properties for shear test
R
=
8
.
3145 Nmm
/
mmolK
T
=
298 K
E
=
90
.
0MPa
ν
=
0
.
20
φ
i
=
10
−
3
mm
4
/
Ns
0
.
80
K
=
0
.
28
·
c
ex
10
−
3
mmol
/
mm
3
c
fc
i
10
−
3
mmol
(
eq
)/
mm
3
=
0
.
15
·
=−
0
.
2
·
10
−
3
mm
3
/
Ns
K
d
=
0
.
28
·
G
c
=
0
.
002 N
/
mm
τ
ult
=
0
.
4MPa
10
−
3
l
a
=
0
.
2mm
v
=
1
.
5
·
mm
/
s
Fig. 23.7
Distribution of
chemical potential
(d
t
=
16
.
6 s). Crack-path is
independent of mesh. Across
thecracklineajumpin
chemical potential is
observed
The result is that the stress at the crack tip is lower and, therefore, crack growth is
slightly slower, but more constant. This has effect on the fluid flow. Decreasing the
nonlocal length and the discretization size by a factor 2 causes faster crack growth.
23.4.2 Delamination Using Continuous Chemical Potential
(Case 2)
A delamination test is performed with a predefined angle of 0
◦
. An initial defect
of length 13 mm is inserted on the left hand side, Fig.
23.9
. The sample is fixed
on the right hand side and is in contact with a filter (
μ
f
0). Crack propagation is
initiated by pulling the sample on the top and bottom over approximate 8 mm with
a fixed velocity of 1
.
0
=
10
−
3
·
mm
/
s. The local fluid distribution is determined by
Eqs. (
23.28
) and (
23.29
).
