Computational validation of dissipative device for the seismic upgrade of historic buildings

The lack of effective connections between sets of perpendicular walls often determines the local or global failure of heritage structures in case of seismic event. In order to address this problem, the paper focuses on retrofitting systems for masonry structures undergoing seismic load. Particularly, it concerns the behavior of two different types of anchoring stabilization systems that avoid the out-of-plane collapse mechanism of a masonry wall and restore the boxlike behavior. The response of the corner connection between two walls was investigated by numerical simulations. Initially, the model was tested in its original configuration to determine the type and the extent of the failure mode when a base acceleration is imposed. Afterwards, a traditional steel anchoring system was implemented in the corner connection to prevent the relative detachment of the walls for the same seismic input. Finally, a friction-based dissipative device was added to the steel ties to provide ductility to the system by allowing for a controlled relative displacement of the walls and reducing the concentration of stresses. The computational analysis showed that implementation of a dissipative device integrated with traditional steel anchors is effective in delaying the complete failure of the anchoring system. Moreover, it provides energy dissipation capacity through controlled displacement, reducing the stress in the surrounding material and allowing the model to withstand a larger intensity input