NEHRP Clearinghouse

Title
Stochastic Response of Single Degree-of-Freedom Hysteretic Oscillators.
File
PB88232624.pdf
Author(s)
Maldonado, G. O.; Singh, M. P.; Casciati, F.; Faravelli, L.
Source
National Science Foundation, Washington, DC., April 1987, 93 p.
Identifying Number(s)
VPI-E-87-5
Abstract
During strong ground shaking structures often become inelastic and respond hysteretically. Therefore, in the study some hysteretic models commonly used in seismic structural analysis are studied. In particular the characteristics of a popular endochronic model proposed by Bouc and Wen are examined in detail. In addition, analytical expressions have also been developed for most commonly used bilinear model as well as another model, herein called as the hyperbolic model. As stochastic response analysis with such models commonly use the stochastic linearization approach which is necessarily iterative, here the convergence characteristics of such methods, when applied to calculate the response of single degree of freedom oscillators, are studied in detail. Several oscillators with different parameters are considered in the study. The ground motions is modeled by a stationary random process with Kanai-Tajimi spectral density function. It is noted that some adjustments in the equivalent linear parameters are necessary to achieve convergence. Also the rate of convergence, the final results is slower for the oscillators with low yield levels. The numerical results obtained by the equivalent linear approach are also compared with the results obtained for an ensemble of ground motion time histories and the possible causes of the discrepancy between the two results are discussed.
Keywords
; Dynamic response; Elastic aftereffect; Ductility; Hysteresis; Models; Earthquakes; Vibration; Stochastic processes; Oscillators; Structural engineering; Dynamic structural analysis