Semi-active fuzzy control for seismic response reduction of building frames using SHD dampers

In this paper, a fuzzy rule-based semi-active control of building frames using semi-active hydraulic dampers (SHDs) is presented. The SHDs are installed between the top of a Chevron bracing and the upper beam on each story to prevent damage to the structure from severe earthquakes. The set of Chevron brace and SHD is modeled as a Maxwell element that consists of a damping element in series with a spring. The rule extraction strategy for semi-active fuzzy control is carried out by genetic algorithm (GA). The objective is to minimize both the maximum inter-story drift and absolute acceleration responses of the structure. Interactive relationships between structural responses and damping coefficients of SHDs are established by using a fuzzy controller. GA is employed as an adaptive method to design the fuzzy controller, which is here known as a genetic fuzzy controller (GFC). To illustrate the efficiency of the proposed intelligent control strategy in application, numerical simulation for a 3-story and a 10-story building frame equipped with multiple dampers is presented.