Experimental and numerical study on the seismic behavior of an external prestressed self-centering frame structure

Abstract

A kind of external prestressed self-centering frame (EPSCF) structure is proposed, and the numerical analytical modeling is given. In such a structure, the pure hinged beam-column joints and column base joints are adopted, the externally prestressed steel strands are utilized to provide lateral stiffness and restoring forces, and the inter-story metal dampers are installed to control displacement response. Based on the quasi-static cyclic tests of the EPSCF test frame, the prestressing forces and the hysteretic behavior of the EPSCF structure are investigated. The test results show that the load-displacement hysteretic curves of the EPSCF without damper exhibit a linear elastic characteristic with small residual displacement, and the load-displacement hysteretic curves of the EPSCF with damper show a full S-shape and significant two-stage characteristics. Installation of the X-type metal damper provides additional stiffness and improves the energy dissipation capacity for the EPSCF. FE model of EPSCF is established, and the hysteretic curves obtained by tests are in good agreement with the numerical simulation results. Parametric analysis indicates that with the increase of the relative stiffness ratio of the lateral stiffness, the seismic response of EPSCF shows a trend of decreasing structural displacement, increasing structural acceleration and base shear. Moreover, the simulation results suggest that the optimum range for the relative stiffness ratio is roughly 0.02–0.10.