Modeling and Validation of a Passive Resettable Stiffness Damper

Abstract

The resetting semiactive stiffness damper (RSASD) has been shown to be effective at controlling vibrations in civil structures in the presence of near-field earthquakes. Although it has the advantages of being mechanically simple and relatively inexpensive, the RSASD requires a multicomponent feedback control system consisting of sensors, a microcontroller, a servo valve, and a battery to operate, rendering it less reliable during a seismic event. In the present work, the resetting passive stiffness damper (RPSD) is presented as an improvement to the RSASD, whereby the RSASD feedback control system is replaced by a novel mechanism to achieve resetting of the damper force. The results of laboratory studies on a small-scale RPSD demonstrate that the resetting mechanism performs as proposed. Results of numerical simulations performed for a five-story base-isolated building subject to four benchmark earthquakes indicate that the RPSD is capable of a similar control performance as the RSASD. Furthermore, it is shown that the RPSD dissipates comparable energy to the RSASD using fewer resets for earthquakes characterized by high peak accelerations and high velocity pulses with long periods, i.e., near-field earthquakes.