Evaluating the effect of infill walls on seismic responses of post-tensioned self-centering concrete frames based on a new analytical model

Abstract

This paper proposes a numerical model with the lump plasticity rotational springs for the simulation of post-tensioned self-centering (PTSC) concrete frames. The analytical connection model that is able to properly capture the joint responses and connection damage is incorporated in the rotational springs. The static and dynamic numerical results are validated against those obtained using the fiber-based structural model. Furthermore, the proposed numerical model is adopted in the seismic response prediction of PTSC frames with infill walls (IWs) and various energy dissipation components. Incremental dynamic analysis is performed through the scaling schemes based on Sa(T1) and PGA, and the effects of IWs and energy dissipators on the structural responses under different ground motion inputs are compared. The numerical results indicate a remarkable reduction in the inter-story drifts of the PTSC frames with IWs as compared to the bare frames under the same Sa(T1). Nevertheless, when subjected to ground motions with large PGAs, the damage of IWs would induce rapidly increased inter-story drifts in the lower floors, which may exceed the drifts of bare frames under the same earthquake intensity. This study highlights the accuracy of the proposed numerical model and the importance of considering IWs in the seismic response predictions of PTSC concrete frames.