Supporting brace sizing in structures with added linear viscous fluid dampers: A filter design solution

Abstract

SUMMARYViscous fluid dampers have proved to be effective in suppressing unwanted vibrations in a range of engineering structures. When dampers are fitted in a structure, a brace is typically used to attach them to the main structure. The stiffness of this brace can significantly alter the effectiveness of the damper, and in structures with multiple dampers, this can be a complex scenario to model. In this paper, we demonstrate that the effects of the brace compliance on the damper performance can be modelled by way of a first-order filter. We use this result to formulate a procedure that calculates the stiffness required by the supporting brace to provide a specified effectiveness of the damping action. The proposed procedure assumes that viscous dampers have been sized in a previous design step based on any optimal methodology in which, as is usually the case, the presence of supporting braces and their dynamic effects were neglected. Firstly considering a one degree-of-freedom system, we show that the proposed method ensures a desired level of damper efficiency for all frequencies within a selected bandwidth. Then the analysis is extended to the case of multi-degree-of-freedom systems to show that the design criteria can be applied in a straightforward and successful manner to more complex structures.

Analysis of damping performance of frame structure with viscoelastic dampers

“…The response reduction is achieved by a combination of brace stiffness and viscous damper coefficients, unlike conventional approaches where damper coefficients are typically optimized independently of brace stiffness (Chen and Chai, 2011). In 2014, Julián et al demonstrate that the effects of the brace compliance on the damper performance can be modeled by way of a first-order filter, and use this result to formulate a procedure that calculates the stiffness required by the supporting brace to provide specified effectiveness of the damping action (Julián et al , 2014). In 2014, Masashi and Takayuki use the connection of viscoelastic damper with a displacement limit mechanism.…”

“…Three types of systems, namely diagonal bracing type, inverted V bracing type and wall type, are tested, which shows that all these systems have damping ratios higher than 8% at small vibration amplitudes on the order of 0.1 mm and the acceleration and the story drift may be greatly reduced (Masashi and Takayuki, 2014). In 2014, Paolo and Massimiliano propose an integrated seismic design procedure of the elastic stiffness resources and viscoelastic properties of a dissipative bracing-damper system (Paolo and Massimiliano, 2014). In 2018, Losanno et al (2018) present a study on the optimal sizing of damping braces of Multi degree of freedom (MDOF) systems equipped with viscous dampers.…”

A lattice‐shaped friction device and its performance in weak‐story prevention

“…Buildings are designed to resist severe earthquakes by dissipating the input energy with these sacrificial devices rather than using structural members. Various PEDDs, such as viscous fluid dampers, viscoelastic dampers, friction dampers, and metallic dampers, are now broadly employed based on their validation through theoretical and experimental research …”

“…Various PEDDs, such as viscous fluid dampers, viscoelastic dampers, friction dampers, and metallic dampers, are now broadly employed based on their validation through theoretical and experimental research. [1][2][3][4][5][6][7][8][9] Among these dampers, metallic yielding dampers and friction dampers differ in the phenomenon used for the dissipation of energy, but the two devices have similar mechanical characteristics. The metallic damper dissipates the input earthquake energy through plastic deformation, whereas the friction damper dissipates energy through friction arising from the relative sliding of two solid bodies.…”