Displacement Demand for Nonlinear Static Analyses of Masonry Structures: Critical Review and Improved Formulations

This paper discusses different formulations for calculating earthquake-induced displacement demands to be associated with nonlinear static analysis procedures the assessment of masonry structures. Focus is placed on systems fundamental periods between 0.1 and 0.5 s, which inelastic amplification usually more pronounced. The accuracy predictive equations assessed based results from time-history analyses, carried out single-degree-of-freedom oscillators hysteretic force–displacement relationships representative First, study demonstrates some limitations two established approaches equivalent linearization concept: capacity spectrum method Dutch guidelines NPR 9998-18, its version outlined in FEMA 440, both overpredict maximum displacements. Two codified relying spectra are also evaluated, namely N2 Eurocode 8 coefficient ASCE 41-17: former proves significantly unconservative, while latter affected by excessive dispersion. A non-iterative procedure, using an linear system calibrated optimal stiffness viscous damping, then proposed overcome problems identified earlier. recently developed modified formulation shown improve limiting dispersion predictions.