ABSTRACT
The shape memory effect of iron-based shape memory alloys (Fe-SMA) can be utilised for prestressing active strengthening of damaged concrete structures. Under cyclic loading, detecting fatigue damage in the alloy is crucial for the long-term fatigue performance evaluation of the Fe-SMA-reinforced structure. This study introduces the piezomagnetic effect as a novel non-destructive method for detecting fatigue damage in Fe-SMA. Uniaxial static and cyclic tensile tests were conducted on Fe-SMA, during which the magnetic field strength and distribution changes on the alloy’s surface were analysed and compared with traditional fatigue damage indicators. The results show that, similar to traditional fatigue damage indicators, the piezomagnetic signal on the surface of Fe-SMA follows a three-stage variation under cyclic loading. Both the magnetic field strength and distribution changes are closely related to material damage. The findings of this study offer promising insights into fatigue damage detection in Fe-SMA-reinforced concrete structures.
