Equivalent linearization method for seismic analysis and design of self-centering structures

Abstract

Although seismic response of engineering structures can be obtained through dynamic nonlinear analysis, approximate linear elastic analysis method is often adopted to reduce the computational effort and simplify the design procedure. Due to the excellent seismic performance, self-centering (SC) concrete structures are receiving more and more attention, but there is no such an equivalent linearization method especially suitable for SC concrete structures. In this study, the influence of hysteretic behavior on maximum inelastic displacement is described conceptually, and the estimation accuracy of four classic equivalent linearization methods are explored for SC models, the results show that the absolute mean displacement errors from classic methods mostly appear in the range of 20% to 30%, and most of the mean displacement errors is negative, which is unsafe for the performance-based seismic analysis and design. Then, an empirical equivalent linearization method is proposed for SC systems by a series of dynamic nonlinear analysis and regression analysis, it is found that the estimation accuracy of the proposed method is better than classic methods, and the standard deviation of the proposed method is basically at the same level as that of the classic methods. Finally, the proposed method is applied to the displacement-based design approach, the nonlinear analysis shows that the design targets can be well meet, and the designed SC concrete structure shows superior self-centering and energy dissipation capacity.