Modeling the Dynamic Behavior of Isolation Devices in a Hybrid Base-Isolation Layer of a Full-Scale Building

Abstract

Measured force-displacement sensing data are analyzed to create nonlinear hysteretic models for elastic sliding bearings and steel dampers. These data were collected during full-scale experimental tests of a base-isolated structure at Japan’s National Research Institute for Earth Science and Disaster Resilience (NIED) “E-Defense” Hyogo Earthquake Engineering Research Center in 2013 that employed historical and synthetic earthquake inputs. Several models are explored for each isolation-layer device, including Coulomb friction models for the elastic sliding bearings and Bouc-Wen hysteresis models for both devices. Parameters for each device model are estimated via constrained nonlinear optimization to minimize model prediction error using testing data. The resulting models are applied to data from other seismic tests to evaluate the models’ ability to provide accurate force predictions. The model for the steel dampers demonstrates the capacity to be generalized across seismic excitations and devices, whereas the model for the elastic sliding bearing reproduces well its behavior during other seismic excitations but is limited to the device to which it was calibrated. The residual error between the model predictions and measurements does not contribute a significant degree of variance in the model parameter estimates.