Investigating the behaviour of steel end-plate connections with shape memory alloy bolts

Conventional extended end-plate connections with normal high-strength steel (HSS) bolts show considerable residual deformation following an earthquake. The application of shape memory alloys (SMAs) has recently been considered in seismic regions because of their capabilities, such as the ability to tolerate cyclic deformations and dissipate energy. In this paper, extended end-plate connections equipped with SMA bolts are investigated. A hybrid extended end-plate connection utilising SMA bolts only for the outer rows and conventional HSS bolts for the remaining rows is a new and viable alternative to existing connections. Finite-element models of connections with different bolt lengths and pre-stressing levels have been developed using Ansys software. The cyclic performance of the models has been assessed and compared. Results indicated that conventional and hybrid connections have better capabilities in energy absorption compared to SMA connections. The hybrid connections and also connections with 69 mm long SMA bolts are classified as high-ductility connections according to the American Institute of Steel Construction (AISC). Increasing pre-stressing over 50% fy has no significant effect on the cyclic performance of connections.