PSI - Issue 64

2080 Sizhe Wang et al. / Procedia Structural Integrity 64 (2024) 2075–2082 Author name / Structural Integrity Procedia 00 (2019) 000–000 by the activation results: the temperatures of anchorage parts were maintained below without any special cooling measures, and the prestress was successfully generated and sustained in the bonded Fe-SMA strip, having no debonding. After the activation, the specimens were either covered with an additional carbon fiber reinforced polymer (CFRP) sheet to form a Fe-SMA/CFRP composite patch. Subsequently, the specimens underwent a series of fatigue tests. More details on the experimental program, fatigue test results, and analysis can be found elsewhere (Wang et al. (2023b), Wang et al. (2024a)). 6

A-150-a

SG3 SG2 SG4 SG1

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(b)

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Fig. 4. Measured strain results. (a) Typical strain history during the cooling process (A-150-a). (b) Final strains along steel plate mid-section width at the end of activation process (c) Average strain of steel plates after activation for specimens with different activation lengths. 4. Conclusions This study presents the activation tests of the repair solution for cracked steel plates using adhesively bonded Fe SMA patches. Prestrained Fe-SMA strips were bonded on both sides of steel plates using a ductile nonlinear adhesive, covering the cracks. Different Fe-SMA strip lengths ranging from 100 to 500 mm were involved, and the middle half areas were activation parts whereas the two ends worked as anchorage parts. A total of six specimens were tested to study the effect of patch length and activation length on the final Fe-SMA prestress level. The electrical resistive heating technique was utilized for activation. In approximately 20‒60 seconds, the electricity heated the Fe-SMA activation part to the target temperature o f 180 ℃, and subsequently the specimens cooled down to the room temperature. Without specific cooling measures, the temperatures of anchorage parts were maintained below the adhesive glass transition temperature.