Introduction
Experimental Details
Materials
Manufacturing
Interface Observation
Tensile Test
Theoretical Model
Thermo-mechanical Model of SMAs Fiber
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From austenite phase into martensite phase:$$ \left\{ {\begin{aligned} &{\upsigma_{\text{s}}^{\text{cr}} + C_{\text{m}} (T - M_{\text{s}} ) < \upsigma < \upsigma_{\text{f}}^{\text{cr}} + C_{\text{m}} (T - M_{\text{s}} )\quad ( {T \ge M_{\text{s}} })} \hfill \\ &{\upxi = \frac{{1 - \upxi_{0} }}{2}\cos \left\{ {\frac{\pi }{{\upsigma_{\text{s}}^{\text{cr}} - \upsigma_{\text{f}}^{\text{cr}} }}\left[ {\upsigma - \upsigma_{\text{f}}^{\text{cr}} - C_{\text{m}} (T - M_{s} )} \right]} \right\} + \frac{{1 + \upxi_{0} }}{2}} \\ \end{aligned} } \right. $$(3)$$ \left\{ {\begin{aligned} & {\upsigma_{\text{s}}^{\text{cr}} < \upsigma < \upsigma_{\text{f}}^{\text{cr}} \quad \left( {T < M_{\text{s}} } \right)} \hfill \\ & {\upxi = \frac{{1 - \upxi_{0} }}{2}\cos \left[ {\frac{\uppi }{{\upsigma_{\text{s}}^{\text{cr}} - \upsigma_{\text{f}}^{\text{cr}} }}\left( {\upsigma - \upsigma_{\text{f}}^{\text{cr}} } \right)} \right] + \frac{{1 + \upxi_{0} }}{2}} \\ \end{aligned} } \right.. $$(4)
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From martensite phase into austenite phase:where \( \upsigma_{\text{s}}^{\text{cr}} \) and \( \upsigma_{\text{f}}^{\text{cr}} \) are the critical stress at both start and finish of transformation. C m and C a are the material constants describing the relationship between temperature and critical transformation stress. M s, M f, A s, and A f are the phase transformation start and finish temperature in austenite and martensite, respectively. a a is a material constant, and equal to π/(A f − A s).$$ \left\{ \begin{aligned} & C_{\text{a}} (T - A_{\text{f}} ) < \upsigma < C_{\text{a}} (T - A_{\text{s}} )\quad \left( {T > A_{\text{s}} } \right) \hfill \\ &\upxi = \frac{{\upxi_{0} }}{2}\left\{ {\cos \left[ {a_{\text{a}} \left( {T - A_{\text{s}} - \frac{\upsigma }{{C_{\text{a}} }}} \right)} \right] + 1} \right\} \hfill \\ \end{aligned} \right. $$(5)
Effective Modulus of SMAs Composite
Results and Discussion
Interface Analysis
Bilinear Behavior of SMAs Composite
Effective Modulus of SMAs Composite
SMAs |
E
a
| 94.4 GPa |
C
a
| 7.5 |
A
s
| 279.5 K |
\( \upsigma_{\text{s}}^{\text{cr}} \)
| 365.9 MPa |
E
m
| 58.4 GPa |
C
m
| 9.3 |
A
f
| 287.1 K |
\( \upsigma_{\text{f}}^{\text{cr}} \)
| 412.7 MPa | |
\( \upvarepsilon_{\text{L}} \)
| 3.37% |
a
a
| 0.413 K−1
|
M
s
| 280.7 K |
\( \upsigma_{\text{f}}^{\text{u}} \)
| 950.1 MPa | |
\( \upvarepsilon_{\hbox{max} }^{\text{f}} \)
| 4.91% |
a
m
| 0.135 K−1
|
M
f
| 257.4 K |
\( V_{\text{f}} \)
| 0.27 | |
Glass/resin |
E
11
| 9.95 GPa |
V
m
| 0.2 |
\( \upvarepsilon_{\hbox{max} }^{\text{m}} \)
| 4.64% |
\( \upsigma_{\text{m}}^{\text{u}} \)
| 468.3 MPa |
E
22
| 3.2 GPa |
Specimens | Data category | Young’s modulus |
\( \upsigma_{\text{c}}^{\text{u}} \)
|
\( \upvarepsilon_{\text{c}}^{\text{u}} \), % | |
---|---|---|---|---|---|
First stage | Second stage | ||||
Single-SMAs-fiber (V
f = 0.22%) | Experimental | 12.65 GPa | 8.83 GPa | 469.1 MPa | 5.25 |
Theoretical | 10.14 GPa | 10.06 GPa | 469.2 MPa | 4.67 | |
Enhancement | 24.75% | −12.23% | −0.02% | 12.42 | |
Three-SMAs-fiber (V
f = 0.65%) | Experimental | 13.82 GPa | 9.18 GPa | 486.0 MPa | 5.16 |
Theoretical | 10.5 GPa | 10.26 GPa | 470.8 MPa | 4.6 | |
Enhancement | 31.62% | −10.53% | 3.23% | 12.17 | |
Five-SMAs-fiber (V
f = 1.08%) | Experimental | 14.54 GPa | 9.56 GPa | 501.2 MPa | 5.10 |
Theoretical | 10.86 GPa | 10.47 GPa | 472.5 MPa | 4.51 | |
Enhancement | 33.89% | −8.69% | 6.07% | 13.08 |