Earthquake Simulator Testing and Analytical Studies of Two Energy-AbsorbingSystems for Multistory Structures

摘要

The study used two different types of energy-absorbing devices to improve theseismic behavior of a large-scale, multistory steel frame building: a viscoelastic shear damper designed using an energy approach, and a friction device with almost perfectly rectangular hysteresis behavior for which an iterative nonlinear analysis design method was adopted. A 9-story, moment-resisting steel frame representing the basic structure of the study was tested with both types of energy absorbers installed and also in moment-resisting and concentrically-braced configurations. The large number of tests permitted numerous comparisons of the four structural systems. The damped structures were found to have base shears similar to the moment-resisting frame while reducing drifts to the level of those of the concentrically-braced frame. Analytical methods suitable for predicting the response of the two damped structures were studied. A linear analysis incorporating damping on a modal basis produced very good results for the viscoelastically-damped system. Furthermore, the use of linear elastic response spectra with high damping gave good results for story shears and displacements. A nonlinear analysis of the friction-damped structure was necessary to predict the response accurately.