Characterisation and optimisation of shape memory alloys for seismic applications

Abstract
The mechanical properties of Shape Memory Alloys (SMA.), used properly in seismic retrofit could achieve an efficient protection of structures subject to earthquakes. In this paper a series of experiments are carried out to characterise different materials given by various manufacturers. In the available literature the references of Shape Memory Alloys used for seismic protection is poor, and the test results do not show clearly the main capacities of these materials, namely the super-elasticity and the energy dissipation. Static and dynamic properties of SMA are given herein, and as the experiments show, a selection of materials was suited to our applications. Given that the dynamical behaviour is rate sensitive, an improvement of the shape memory device is also proposed, giving good results for futures applications. Finally, an example of application on a masonry wall tested in real scale and under severe earthquake records, in ELSA. Laboratory, with the pseudo dynamic method, shows the efficiency to reinforce part of structures with SMA. devices.