A practical method for optimum seismic design of friction wall dampers

Friction control systems have been widely used as one of the efficient and cost effective solutions to control structural damage during strong earthquakes. However, the height-wise distribution of slip loads can significantly affect the seismic performance of the strengthened frames. In this study, a practical design methodology is developed for more efficient design of friction wall dampers by performing extensive nonlinear dynamic analyses on 3, 5, 10, 15, and 20-story RC frames subjected to seven spectrum-compatible design earthquakes and five different slip load distribution patterns. The results show that a uniform cumulative distribution can provide considerably higher energy dissipation capacity than the commonly used uniform slip load pattern. It is also proved that for a set of design earthquakes, there is an optimum range for slip loads that is a function of number of stories. Based on the results of this study, an empirical equation is proposed to calculate a more efficient slip load distribution of friction wall dampers for practical applications. The efficiency of the proposed method is demonstrated through several design examples

EACS 2016 paper - A Practical Design Method for Seismic Strengthening of RC Frames Using Friction-Based Passive Energy Dissipation Devices

<div>EACS 2016 Paper No. 120 (113)</div><div><br></div>In this paper, a practical design solution for more efficient design of friction-based passive control systems is suggested, by considering the selected design earthquakes. In general, the effectiveness of the friction-based supplemental dampers is limited to a narrow range of slip loads. In addition, height-wise slip load distribution pattern can notably affect the overall seismic performance of the structures controlled with friction devices. In this study, the efficiencies of five different height-wise slip load distribution patterns for friction-based passive dampers are first compared; and accordingly, a practical solution for slip load distribution is proposed. The studied system consists of a non-structural concrete panel with a friction connection at the top and three more peripheral supports to provide appropriate boundary condition for the concrete wall panel. To assess the effectiveness of the supplemental friction wall system, extensive nonlinear dynamic analyses have been conducted on 3, 5, 10, 15, and 20-storey RC frames subjected to seven real and synthetic spectrum compatible earthquakes. Subsequently, an empirical equation is suggested to design RC frames with friction wall dampers. The preliminary results show that using the proposed equation can significantly improve the seismic performance of the controlled structures.<br