Reinforcement of Masonry Walls under Cyclic Loads using Shape Memory Alloys

Unreinforced masonry construction is particularly susceptible to failure under severe external loading, with consequences that can extend well beyond structural damage to significant socio-economic loss. Among emerging retrofitting strategies, smart materials such as shape memory alloys (SMAs) offer a novel avenue for passive structural control, capable of recovering deformations of up to 10% through their superelastic behavior while simultaneously dissipating energy. This work examines the response of an SMA-reinforced masonry wall subjected to cyclic loading, with a peak intensity of 200 kN/m² applied at 10-second intervals. The wall geometry corresponds to an interior partition of a residential building in Oran, Algeria, modelled in Building Information Modelling (BIM) software and subsequently transferred to a structural analysis platform. Nonlinear finite element simulations were performed in Ansys APDL, with the inelastic response of brick and mortar captured through a rate-independent plasticity formulation. Incorporating a single nickel–titanium (NiTi) SMA device is shown to lower the wall's maximum displacement from 2.37 mm to 1.18 mm (a 50% reduction) and its peak stress from 2.40 MPa to 1.66 MPa, with residual stress in the retrofitted wall falling below 0.8 MPa by the end of the loading cycle. These outcomes highlight shape memory alloys as a viable, cost-effective means of enhancing the seismic safety of masonry structures.