Experimental investigation on seismic response control of adjacent buildings using semi-active MR dampers

This paper reports an experimental study on semi-active seismic response control of adjacent building structures using magneto-theological (MR) dampers. A 1:15 scaled adjacent structural system consisting of a 12-story building model and an 8-story building model was tested on shaking table with MR damper passive and semi-active control. An MR damper with large stroke is specifically designed for this study. After experimentally identifying dynamic characteristics of the individual MR damper and the uncontrolled structural models, the two building models are interconnected with the MR damper at different floors and semi-active control is implemented using the dSPACE DS1005 real-time control system. The structures are excited on their base by a shaking table imposing sweep sine excitation and El Centro earthquake excitation. A stochastic optimal control strategy proposed by the authors is applied through the dSPACE system and its MATLAB environment to accomplish real-time semi-active control from the measurement of displacement and velocity responses at each floor. This control strategy results in a dissipative energy control with its feedback control force being a nonlinear generalized damping force. The structural response under semi-active control is compared with that by using the MR damper as a passive device without voltage input. Different MR damper installation locations are addressed in the experimental study to search for maximum response mitigation capability.