An efficient numerical tool for 1-dof nonlinear systems towards large-scale seismic structural health monitoring of masonry buildings

A nonlinear constitutive model, combined with an ad-hoc developed numerical strategy, is proposed to study the nonlinear dynamics of masonry buildings approached through single degree-of-freedom systems (1-dof). This proposal is explicitly aimed at providing enhancements in designing tools for seismic structural health monitoring in large-scale urban contexts. The model incorporates plasticity and damage induced by friction and wear, and it is capable of capturing the nonlinear response of structures subject to general external time-dependent loads. A numerical algorithm to solve the ensuing piecewise nonlinear equations is devised and explicitly implemented in a low-level language, thus being optimized for specific hardware systems for structural health monitoring. The proposed formulation is initially tested to validate the model’s constitutive parameters by identifying them in pseudo-static regimes, according to the experimental behavior of a real-scale single-storey masonry building. Then, the numerical stability of the proposed code is examined in comparison with traditional numerical solvers. Finally, the effects of real seismic actions are investigated, with particular emphasis on the accumulated damage when subsequent quakes are considered.