Semipassive Resettable Stiffness Damper for Seismic Protection of Short-Period Structures: Fid-Bau Portal

Semipassive Resettable Stiffness Damper for Seismic Protection of Short-Period Structures

Walsh, Kenneth K. / Sallar, Grace / Steinberg, Eric P.

In the present study, a semipassive resettable stiffness damper using motion amplification in the resetting mechanism is presented for seismic protection of short-period structures. Validation of the resetting mechanism with amplification was achieved through damper hystereses obtained from laboratory testing of a small-scale prototype. Numerical simulations were performed for a 3-story scaled building model subject to three benchmark earthquake ground motions. The results showed that increasing amplification led to more overall energy dissipated by the damper and a better structure response. However, it was shown that increasing amplification also resulted in more partial resets of the damper, and a reduction in the damper efficiency. Using a programmable valve in place of an on-off valve to reduce partial resets resulted in a poorer damper performance, which was attributed to the programmable valve being in the open position for a longer period of time during the earthquakes. It was concluded that motion amplification is an effective means of enhancing the energy dissipation of the damper in the presence of small piston displacements.