Hybrid base-isolation with magnetorheological damper and fuzzy control

A series of large-scale experimental tests is conducted on a mass equipped with a base-isolation system that consists of high damping rubber bearings (HDRB) and a 300 kN magnetorheological (MR) damper. The 21 772 kg mass and its hybrid isolation system are subjected to various intensities of near- and far-fault earthquakes on a large shake table. Three proposed fuzzy controllers use feedback from displacement, velocity, or acceleration transducers attached to the structure to modulate resistance of the semi-active damper to motion. Results from various types of passive and semi-active control strategies are summarized and compared. The study shows that a combination of HDRB isolators and an adjustable MR damper can provide robust control of vibration for large civil engineering structures that need protection from a wide range of seismic events. Low power consumption, direct feedback, high reliability, energy dissipation, and fail-safe operation are validated in this study.