Structural Performance of Precast Diaphragms Connected with Shape Memory Alloy Connectors

In precast construction, a building's structural integrity largely depends on the floor, usually composed of individual precast panels. These panels are typically connected along their length using mechanical connectors, which can experience significant residual deformations when subjected to seismic forces. These deformations can render the structure unrepairable. This paper aims to investigate the feasibility of using shape memory alloys (SMA) as connectors in precast concrete floors to enhance the earthquake resilience of precast structures. SMA connectors show promise due to their ability to withstand substantial deformations and return to their original state, thereby mitigating the large residual deformations associated with conventional steel connectors. This study modelled and analysed a precast structure under an earthquake ground motion obtained from the PEER Ground Motion Database to examine the seismic behaviour of SMA connectors compared to traditional steel connectors. Results of the numerical model show that the SMA connectors exhibit similar trends in relative shear and tension deformations at locations across the diaphragm but with magnitudes higher by 2–3 times. Following the seismic motion, the SMA connectors resulted in much reduced residual deformations than the case of steel connectors, with a reduction factor of up to 16.