Environmental Engineering Reference
In-Depth Information
a
−
2ln10
,
M
a
=
b
=
( 15 )
M
M
MM
−
C
s
f
M
The shape functions for phase transition are valid on certain stress-dependent
temperature domains which can thus be plotted on the
T
,
s
-plane (see Fig. 13).
s
M
C
M
C
A
A
M
f
M
s
A
s
A
f
T
Figure 13:
T
,
s
-phase diagram from the Tanaka model. The arrows indicate in
which direction of the
T
,
s
-path the phase change occurs.
Here the graphical representation of the Clausius Clapeyron constant can
also be seen. Tanaka actually defi nes
b
A
and
b
M
in terms of the height of the
transition band:
2ln10
b
Δ=
s
( 16)
A
A
s
−
2ln10
b
Δ=
( 17)
M
M
This constitutes the same as eqns (14) and (15) because of the defi nition of the
Clausius Clapeyron constants:
Δ
s
A
C
=
( 18)
A
AA
−
f
s
Δ
s
M
C
=
( 19)
M
MM
−
s
f
Liang and Rogers propose a similar model, but with a cosine-shaped dependency
of
x
on
T
and
s
.
For
CTM
(
−−
)
(
p
/ |
b
|)
≤≤
s
CTM
(
−
) :
M
f
M
M
f
1
−
x
1
+
x
(20)
A
A
x
=
cos(
aTM
(
−
)
+
b
s
)
+
M
f
M
2
2
for the AM transition. For the MA transition the following holds.
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