Predicting the displacement of triple pendulum™ bearings in a full-scale shaking experiment using a three-dimensional element


Correspondence to: Keri L. Ryan, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, U.S.A.



The accuracy of a series spring model to predict the peak displacement and displacement history of Triple Pendulum™ (TP) bearings in a strongly shaken, full-scale building is evaluated in this paper. The series spring model was implemented as a self-contained three-dimensional TP bearing element in OpenSees and is now available for general use. The TP bearing element contains the option for constant friction or a generalized friction model that accounts for the effect of instantaneous velocity and compression load on the friction coefficient. Comparison between numerical simulation and experimental data of a five-story steel moment frame building shows that the peak displacement of isolation system can generally be predicted with confidence using a constant friction coefficient model. The friction coefficient model accounting for the effect of axial load and velocity leads to minor improvement over the constant friction coefficient models in some cases. Copyright © 2013 John Wiley & Sons, Ltd.