Estudio paramétrico de estructuras con aislación sísmica considerando el uso de factores de reducción de resistencia mediante modelos de 2GDL.

Abstract

His project analyzes the impact of reduction factors (R) on seismically isolated structures using two-degree-of-freedom (2DOF) models implemented in OpenSeesPy. The main objective is to optimize structural design and ensure safe and efficient seismic performance, addressing uncertainties related to the R-values recommended by international standards, such as ASCE 7-16. For this purpose, simplified mathematical models of 1 and 2 degrees of freedom were developed for structures with and without isolation systems. Nonlinear time-history analyses were performed using real seismic records to evaluate dynamic responses such as displacement, forces, and ductility. The study employed elastic response spectra, direct integration algorithms, and proportional damping to simulate the structural behavior under seismic loads. The results demonstrate that isolation systems significantly reduce displacements and ductility demands in most cases. However, when R-factors exceed certain values, ductility demands in isolated structures may surpass those of fixed-base structures, depending on the isolator’s characteristics and the natural period. This highlights the need for careful design considerations. It is concluded that seismic isolation is effective in optimizing structural performance, although its effectiveness diminishes with longer periods or higher R-factors. It is recommended to extend the analysis with additional seismic records and explore variations in the stiffness of isolation systems to enhance their design. Keywords: Seismic isolation, reduction factors, ductility, parametric analysis, OpenSeesPy