The optimum design of a base isolation system with frictional elements

A linear multistorey structure with a seismic base isolation system consisting of rubber bearings and frictional elements is considered. The non‐linear equations of motion are derived for the first mode vibration and the stochastic response to a white noise ground acceleration is determined. Based on this response, suitable objective functions are defined and the optimum design of the isolation system is performed. It is shown that a small amount offriction increases the effectiveness of the system compared with the same system but without frictional elements.