Adaptive causal realization of rate-independent linear damping

The adaptive control approach is demonstrated through the real-time hybrid simulation (RTHS) of a 5-story base-isolated building and a 14-story inter-story isolated building. A magnetorheological (MR) damper is added to the isolation layer of each structure to provide supplemental control mimicking ideal RILD. The MR damper is experimentally represented while the remainder of the structure is numerically simulated in the RTHS loop. The desired damping force is tracked by the semi-active damper, which is naturally in phase with velocity and has a controllable magnitude. The results compare well to noncausal numerical simulations in both damping forces and structural responses. Results also show clear improved seismic performance of the adaptive algorithms as compared to non-adaptive causal approximations of RILD and passive-on and off damper controllers (i.e., nonlinear hysteretic damping).