Nonlinear static analyses based on either inelastic or elastic spectra with equivalent viscous damping: A parametric comparison

This paper specifically deals with the latter and proposes a parametric comparison between two wide classes of methods formally based on conceptually alternative approaches for defining the demand spectra in nonlinear static analyses of dissipative structures. First of all, the paper outlines the main conceptual aspects of such alternative methods and reports their key operational details. Particularly, it proposes a dimensionless formulation of their relationships and demonstrates that both methods are based upon a small and almost common set of dimensionless parameters. Therefore, a wide parametric analysis is proposed to compare the ductility demand obtained by means of these two alternative methods with the aim of describing and quantifying the different predictions obtained by applying such methods. Finally, the results of nonlinear time-history analyses are proposed for assessing the two aforementioned methods.