Resilient active seismic response control of structural systems

This paper proposes a dissipative resilient observer and controller (DROC) design for a network controlled system (NCS) that handles faults, implementation errors, or cyberattacks that can be modeled as bounded controller or observer gain perturbations. It presents linear matrix inequality (LMI) conditions for the robust stability of the system in the presence of bounded perturbations in the observer and controller. Furthermore, a new LMI-based time-delay control (TDC) algorithm that mitigates the effects of perturbations due to time-delays in the NCS is introduced. The robust methodology is applied to active control of a scaled model of a structural system equipped with an active mass driver system. The results demonstrate that the proposed methodology is robust and ensures stable system response due to various types of earthquake base excitations.

TREND OF SEISMIC RESPONSES OF EXISTING HIGH-RISE RC BUILDINGS

This report presents studies on the seismic response of high-rise RC buildings in Japan. Data concerning the seismic response of approximately 600 high-rise RC buildings constructed from 1972 to 2015 were collected. Seismic response characteristics were analyzed by focusing on differences in seismic resistant structures, seismic response control structures, and seismic isolation structures. The results indicated that the maximum story drift ratio response under the level 1 study seismic ground motion (R) and the level 2 study seismic ground motion (R) criteria is smaller for seismic isolation structures than that of the seismic resistant structure and seismic response control structures. In addition, focusing on the R-R relationship, the correlation is low in the seismic resistant and seismic response control structures, but is almost linear in the seismic isolation structure. This is because the seismic isolation structure is designed such that the superstructure does not become plastic even with level 2 seismic ground motion.

Power Analysis of Sdof Structures with Tuned Inerter Dampers Subjected to Earthquake Ground Motions

Tuned inerter dampers (TID) have been demonstrated as efficient energy dissipation devices for seismic response control. However, its potential capability for energy harvesting remains largely unexplored. Here, we present a theoretical analysis of the power of a structure-TID system subjected to earthquake ground motions. The analytical solutions of the average damping power of the system are derived for considering white noise base excitations and the Kanai-Tajimi earthquake model, respectively. Comparisons of the numerical results of a Monte Carlo simulation and the theoretical predictions verify the accuracy of the analytical solutions. Besides, we uncover the influence of the TID parameters on the damping power and output power of the system. The optimal frequency ratio of the TID for maximizing its output power slightly differs from that for seismic response control, and the former varies with site conditions. In contrast, both the damping power and output power are not sensitive to the damping ratio of the TID. For short-period structures, a small inertance-to-mass ratio (µ) of the TID is beneficial to maximize its output power, while seismic response control requires a large µ. For long-period structures, the damping power and output power are not sensitive to the µ. Generally, a structure-TID system on a soft soil site absorbs more energy from a given earthquake and is capable of harvesting more energy than that on a hard soil site. This study may help develop new strategies for self-powered control and monitoring in civil structures.