Recent Advances in Dynamic Identification and Response Simulation of Hybrid Base Isolation Systems

A physical model composed of a tri-linear spring, a friction slider and a viscous damper is proposed for the simulation of the dynamic behaviour of hybrid base isolation systems (HBIS) composed of high damping rubber bearings (HDRB) and low friction sliding bearings (LFSB). After the introduction of the constitutive equations for each device composing the overall system, it is shown that the motion of the system consists of alternating linear phases. An analytical solution is provided in compact form for all possible phases of motion. The end conditions for one phase provide the initial conditions for the next one. The solution is applied to the dynamic identification of the HBIS of the Solarino buildings. A well established evolution strategy (CMA-ES) is used as the dynamic identification algorithm. The estimated values of the physical parameters, together with simulated test responses, contribute to a better understanding of the behaviour of HBIS.