A Novel Nonlinear Control System with Emphasis on Nonstructural Performance (2003-2004)

Most control techniques in the structural engineering literature are aimed at improving performance of the primary structural part, but they may have limited or reverse effect on the nonstructural component during strong seismic events. In this paper, we emphasize the nonstructural performance using a cubic nonlinear active control system optimized in the frequency response functions of an SDOF nonlinear isolator. An eight-story base isolated benchmark building recently proposed by the ASCE community is studied as a demonstration. Both the structural and nonstructural performance indices are proposed in this research. We compare our cubic control effect with that of an LQG-based semiactive damping control system. It is shown from the simulation results that, in most design cases, the cubic control system has much better nonstructural performance while still maintaining good performance of the primary structural part. Further research of this cubic control system is also addressed.