Nonlinear adaptive control of flexibly-supported inelastic asymmetric steel structures equipped with MR dampers

Abstract

Despite previous studies, this paper simultaneously addresses the challenges of soil-structure interaction (SSI) and nonlinear structural behavior in torsionally irregular building structures equipped with magnetorheological (MR) dampers, utilizing a supervisory nonlinear adaptive control procedure. This represents a significant step toward improving the design of earthquake-resisting structures. In order to consider the effects of torsional behavior on the performance of semi-active MR control systems, various inelastic asymmetric steel structures with different periods, eccentricities, and torsional-to-translational frequency ratios based on supports with different levels of flexibility were used. In these structures, the steel elements were modeled by the extended plasticity (fiber) while the support flexibility effects were accounted for based on the substructure method in OpenSees software. A new model-based nonlinear adaptive control algorithm was employed to control a wide range of structures subjected to various seismic records in bi-directional excitation, incorporating the effects of support flexibility. Results show that the MR dampers reduce the Engineering Demand Parameters (EDPs) significantly, considering the effects of the soft and stiff edges of the structure in various scenarios. Analysis of the effects of the support flexibility on the MR damper performance demonstrated the successful function of the damper in improving the seismic performance of such structures.