EACS 2016 paper - Performance evaluation of a filter-based pseudo-negative stiffness control for seismically isolated structures

2017-03-28T15:16:50Z (GMT) by Wei Gong Shishu Xiong
EACS 2016 Paper No. 196

Research shown in this paper is focused on the development of a new filter-based pseudo-negative stiffness (FPNS) control algorithm, which aims to overcome the challenge of the sudden change of control force produced by the conventional PNS control force. The strategy of this method is to produce a negative stiffness friction damping force with a gradual change at velocity switches by employing a low-pass filter. By investigating the time-history curves and the hysteresis loops of the FPNS control force, it is found that the low-pass filter also enables the control force at the original position increases with increasing seismic intensities and helps roll off the high-frequency component of the control force. Only the relative displacement of control devices is required for measurement. 
A semi-active design is developed to produce the desired reference control force by MR dampers. The structure used for numerical simulation is the base-isolated benchmark building. Seismic responses of the FPNS control, the simple displacement PNS control, the sample semi-active control and the optimal viscous damping control are compared under different seismic intensities. The effectiveness of each control case is evaluated based on the 'ideal isolation control principle'. The results show that the FPNS control can improve the isolation functionality for both low-to-moderate and extreme seismic intensities as well as enhance the isolation safety.