Backstepping control of nonlinear building structures with hysteretic and frictional dynamics

This paper deals with the problem of vibration attenuation of a class of nonlinear base isolated building structures. Magnetorheological (MR) damper is used as the semiactive control device whose nonlinear hysteretic behavior is modelled by means of the Bouc-Wen model. Backstepping control scheme is proposed to generate the control force of MR damper needed for attenuating structural vibrations. In the controller design, the nonlinear frictional forces generated by the base isolator and the structural vibrations produced by uncertain disturbances such as earthquake accelerations are taken into account. The effectiveness of the proposed backstepping controller is verified through a semi-actively controlled 10-story frictional base isolated building subject to the seismic excitation of the Taft earthquake.