A Simplified Multivariant SMA Model Based on Invariant Plane ...

Figure 9: Effective stress at the onset of transformation vs. the hydrostatic stress at the onset of
transformation for a polycrystalline Cu71Zn25Al4 (wt%) <strong>SMA</strong> with a volume change of - 0.3% at a
temperature of 25 °C. Each number corresponds to a 1D or 3D loading in table 4 (after Gall et al. (Gall et
al., 1998)).
Effective Stress (x10 6 Pa)
400
300
200
100
0
0
5
10 15 20
Effective Strain (x10 -3
)
34
Pure Tension (#1)
Zero Hydrostatic Pressure (#2)
Pure Compression (#3)
Triaxial Compression (#4)
Triaxial Compression (#5)
Triaxial Compression (#6)
Figure 10: <strong>Simplified</strong> <strong>Multivariant</strong> model predictions for effective stress-strain plots for a polycrystalline
Cu71Zn25Al4 (wt.%) with a volume change of - 0.3%. The test temperature is at 25 °C with the equilibrium
temperature T0= - 3 °C, and T0′= - 24 °C. Each one of the curves corresponds to a 1D or 3D loading shown
in table 4. See text for details.
25
30