The Earthquake Engineering Online Archive

Earthquake simulator testing and analytical studies of two energy-absorbing systems for multistory structures

Aiken, Ian D.; Kelly, James M.

UCB/EERC-90/03, Earthquake Engineering Research Center, University of California, Berkeley, 1990-10, 276 pages (545.1/A44/1990)

This combined experimental and analytical study focuses on the use of two different types of energy-absorbing devices to improve the seismic behavior of a large-scale, multistory steel frame building. The energy-absorbing devices studied are a viscoelastic shear damper designed using an energy approach and a friction device with almost perfectly rectangular hysteretic behavior for which an iterative nonlinear analysis design method was adopted. Extensive earthquake simulator testing of both systems was carried out. A nine-story, moment-resisting steel frame represented the basic structure of the study. The structure was tested with both types of energy absorbers installed and also in moment-resisting and concentrically braced configurations. The large number of tests performed permitted numerous different comparisons of the four structural systems, particularly with respect to base shear and drift. Analytical methods suitable for predicting the response of the two damped structures were then studied. Considered were how accurate a linear analysis incorporating damping on a modal basis was for producing results for the viscoelastically damped system and whether the use of linear elastic response spectra with high values of damping gave good results for story shears and displacements. A nonlinear analysis of the friction-damped structure was necessary to predict the response accurately. A previously developed and extensively used nonlinear time-history analysis program was used and the friction devices were modeled using existing elements.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-90-03.pdf (16 MB)