Centrifuge modelling of structures with oil dampers under seismic loading

Abstract

Summary Experimental research into the seismic performance of buildings with passive oil dampers has so far been restricted to large‐scale testing of frames erected on laboratory shaking tables that ignore the foundation soil below. This simplification of the problem falls short of replicating dynamic soil‐structure interaction that would occur in the field. This paper presents the first experimental attempt at utilising high gravity dynamic centrifuge testing to replicate the response of a damped building at a reduced model scale. The paper compares the dynamic response of two similar two‐degree‐of‐freedom model sway frames, one control (bare) frame and one frame equipped with miniature oil dampers, both structures founded on shallow raft foundations in dry dense sand. The miniature oil dampers successfully mitigate floor accelerations, drifts, and storey shear forces in the damped frame with minor modification to the frame stiffness. For strong, near resonance motions, global rocking of the undamped frame associated with physical uplifting of the foundation from the soil surface and subsequent yielding of sand beneath has led to floor acceleration levels, which are comparable to those obtained in the damped building fitted with miniature oil dampers. Assessment of the instrumentation installed on the miniature oil dampers reveals a viscoelastic damper behaviour with a dependency on stroke magnitude and on velocity.

Application of first‐order finite similitude in structural mechanics and earthquake engineering

“…Note, however, it is possible to achieve the identity for the FVDs with a change in damping fluid. This is a practical change but it does require that the damping fluid has an appropriate viscosity 54,55 . Both these options are explored here.…”

“…This is a practical change but it does require that the damping fluid has an appropriate viscosity. 54,55 Both these options are explored here.…”

A novel stochastic linearization technique for structures with nonlinear fluid viscous dampers including soil-structure interaction

“…Huergo et al [4] also showed that soil flexibility could decrease the equivalent damping ratio of FVDs, and increase the displacement of tall buildings on soft soils. More recently, experimental research by Boksmati et al [5] found that SSI can reduce the energy dissipated by the dampers. De Domenico et al [6] investigated the effect of soft soil conditions on the seismic performance of Tuned Inter Dampers (TID) by modeling the seismic accelerograms as a filtered Gaussian random process.…”

Sustainable Measures for Protection of Structures Against Earthquake Induced Liquefaction

“…It was also shown that significant damping is afforded by the foundation soil that can be beneficial in reducing the earthquake-induced vibrations in portal frame structures. More recently Boksmati and Madabhushi [6] studied model structures fitted with viscous dampers and tracked the energy dissipation in the viscous dampers as well as in the foundation soil. They concluded that dynamic soil-structure interaction and consequent damping in the foundation soil can benefit the overall structural performance during a seismic event.…”