Experimental and numerical investigation on a passive control system for the mitigation of vibrations on SDOF and MDOF Structures: mini Tribological ROCKing Seismic Isolation Device (miniTROCKSISD)

Abstract

This paper illustrates the results of an experimental campaign performed on a scale prototype of a base dissipator called Mini Tribological ROCKing Seismic Isolation Device. This device allows a smooth, controlled and damped rocking by means of frictional layers and viscous elastic springs, which aim to decouple the frequencies of the superstructure, dissipate energy during motion and re-centering the system once the action is removed. Four superstructures are tested -a shear type frame, braced and unbraced, a multi-storey frame and a SDOF oscillatorwith 96 ambient vibration and impulsive tests. An analytical model is illustrated and validated by the experimental tests. The reduction of relative displacement demand is analyzed for all the cases together with the reduction of the acceleration demand, showing positive effects of the base dissipator on the dynamic behavior of all the superstructures.

Human-Induced Vibrations on Museum Artefacts: Literature Review and Calculation Example

“…The cost of adding springs and dampers is relatively low compared to other solutions and it has been proven that it's a widely used practice in the museum industry to safeguard artworks. For example, recently, a base dissipator with frictional curved base surface and circumferential springs and dashpots was developed to protect museum artefacts from earthquakes-induced vibrations [39] [40] or human-induced ones [41]. In terms of feasibility, the isolators can be easily adjusted to accommodate the weight and size of the object, they can be customized to fit the specific dimensions of the display case and they do not require any major modification to the museum's infrastructure.…”

Equivalence of Damping Properties of Dissipative Devices for Mitigating the Seismic Risk of Rigid Blocks

“…( 1) and ( 3) with the condition . The transition from the equations valid for restrained blocks to those suitable for free-standing blocks is considered with a fracture function proposed by (Makris and Black 2002) [5], [6] so expressed: when when (4) where is the block rotation corresponding to the yielding of the horizontal restraint.…”

“…The viscous-elastic damper can be located at the base of the rocking block [2] or to a certain height from its base with the purpose of mitigating the seismic vulnerability. The perspective is the same as that adopted in the damage avoidance design, which protects the structure from damage allowing motion [3], [4] Analytical and numerical approaches have been provided studying the uplifting of anchored blocks [5], [6], and similar approaches have been applied to masonry structures to study the behavior of masonry walls restrained by tie-rods [7]- [9]. Some other contributions, including their seismic assessment through probabilistic approaches, were related to furniture, electric or mechanical equipment anchored at the base [10]- [13].…”

Displacement‐based design procedures for rigid block isolation

“…The subject of base isolation technology used for seismic protection in general has received extensive attention in recent decades, [20][21][22] and numerous investigations into response control and seismic isolation were conducted. Remarkable progress has been achieved in advancing these technologies, 23,24 which fall in the well-known "passive control" category of structural control.…”