Smart structures using MR dampers with second order sliding mode control

This paper presents the design of a second-order sliding mode controller using Magneto-rheological (MR) fluid dampers integrated in smart structures to sustain external earthquakes or dynamic loadings. The advantages of these structures come from the use of semi-active devices for the fail safe operations and low energy consumption. However, the control of MR dampers is hindered by their nonlinear force-displacement and hysteresis force-velocity responses which usually affect control performance. On the other hand, the required yielding force to suppress structural vibrations results from the magnetization of the fluid particle suspension in the damper housing via the controlled current. To robustly control the dampers' magnetization current, the sliding mode control methodology is adopted. Simulation results and evaluation are included to show effectiveness of the proposed approach.