Moment equation analysis of base-isolated buildings subjected to support motion

The stationary response of base-isolated buildings subjected to support motion is studied. The isolation device consists of a friction device, while the ground motion is assumed to be a stationary Gaussian white noise random process. The moment equation approach is preferred in this study to characterize the structural response statistically. A non-Gaussian closure is adopted to reveal the degree of non-Gaussianness of the response. The proposed approach is compared with the stochastic equivalent linearization and the numerical simulation, resulting in more accuracy when predicting the moments of the response which is markedly non-Gaussian. The models of cascaded and coupled system for the base isolator and the building are also compared, finding the former to be quite in error.