PSI - Issue 33

5

Emanuele Sgambitterra et al. / Procedia Structural Integrity 33 (2021) 1073–1081 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1077

a)

b)

Fig. 2. a) Isothermal (T=25 °C) stress-strain curve of the SMA wire; b) differential scanning calorimetry thermogram of the SMA with measured transformation temperatures. Figure 3.b summarizes the results in terms of activation temperatures, one-way and two-way shape recovery strain.

a)

b)

Fig. 3. a) Recovery strain,  rec , as a function of the activation temperature; b) transformation temperatures TTs as a function of the applied pre strain.

2.3. SMA-polymer sample: manufacturing and testing SMA-polymer samples were manufactured for pull-out tests to measure the adhesion strength under different thermo-mechanical loading conditions. Samples are made of a SMA wire embedded along the central axis of a cylindrical polymer block with diameter of 10 mm and axial length of 20 mm. A special Teflon mold was used for sample manufacturing, that allows precise SMA wire alignment in the polymer block. Polymer setting was carried out according to the manufacturer recommendations: curing at 25 °C for 48 h.