Design and Development of a SMA-Based Device for the Protection of Masonry Arches and Vaults: Investigation On the Use of Different Types of SMAs

Arches and vaults are structural systems widely used in ancient times especially in civil and religious masonry buildings. Metallic tie-rods are commonly used in these structures to absorb the lateral thrusting forces due to gravity loads or inertial forces caused by the vertical component of a seismic event but with some limitations (e.g. sensitivity to temperature variations, buckling under compression, etc.). Shape memory alloys (SMA’s) may be used in series with metallic tie-rods in order to improve the overall behaviour of the structure both under service and ultimate loading conditions. In the present work the results of a wide experimental program aimed at verifying the effectiveness of the proposed SMA-based device prototype are reported. In the experimental tests both NI-Ti and Cu-based SMA wires have been examined in order to optimize the performances of the SMA-based device based on the seismic hazard and expected thermal variations of the site.