PSI - Issue 47

Stefano Rodinò et al. / Procedia Structural Integrity 47 (2023) 579–588 Carmine Maletta / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 5. Final prototype

3.2. SMA-composite prototype The final prototype was tested by using the setup shown in Fig. 6. The thermal load is done by Joule’s effect, by applying a DC current with a maximum value of 2 A. This current value was selected based on preliminary experiments made for a full thermo-mechanical characterization [20]. It was shown that a maximum temperature of around 180 °C was obtained in the SMA wire, as directly measured by a type k thermocouple (see Fig. 6(a)), corresponding to maximum deflection of the composite beam of around 120 mm. The silicone sleeve allows to reduce the temperature at the silicone-polymer interface down to 115 °C. It was shown that activation temperatures above this value (180 °C) does not provide any deflection increment and could represent a threat for both SMA and polymer damage.

Fig. 6. Experimental setup developed to characterize the active composite during its activation through electrical current.