A NEW METHOD FOR THE SEISMIC DESIGN OF STRUCTURES WITH BILINEAR ISOLATORS USING INELASTIC SPECTRA

This paper presents the concept of inelastic capacity design spectra for the design of base-isolated structures; particularly those structures using isolators with a bilinear hysteretic behavior when subjected to dynamic loading. The inelastic capacity design spectra relate peak nonlinear accelerations, velocities, displacements and effective isolated natural periods for bilinear systems with a given yield strength and post yield stiffness. Inelastic capacity design spectra could be useful for the design of base isolators with bilinear hysteretic behavior, as these devices can be designed for a fixed yield strength and post yield stiffness. The concept of inelastic capacity design spectra and its application for the design of base isolated structures is illustrated with the case study of a particular structure.