Controle de vibrações em edifícios submetidos à ação de cargas dinâmicas utilizando amortecedor de massa sintonizando na forma de pêndulo / Vibration control of structures subjected to dynamic loads using tuned pendulum-shaped mass dampers

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The ongoing progress of structural analyses and dimensioning, in addition to the continuous advancements in building techniques and material, has made it possible to build taller and more slender structures every day. These structures are also more vulnerable to excessive vibrations caused by dynamic loads like earthquakes, winds, waves, intense traffic, and human occupation, amongst others. In order to reduce those excessive vibrations, a structural control system can be used, which will absorb part of the structures energy, improving its performance in relation with such disturbances. In this work, the efficiency of a tuned pendulum-shaped mass damper is evaluated in the reduction of the displacement, velocity and acceleration of a structure when it is subjected to dynamic excitations. The optimum parameters for the damper are also presented (cable length and damping ratio for the pendulum) when the main system or structure is subject to random ambient excitation, given by power spectral density functions. Initially, both the alterations produced by earthquakes as well as the ones produced by winds will be studied, taking into consideration a constant spectral density (white noise); subsequently, more realistic spectral density functions, like Kanai- Tajimis, when dealing with seismic alterations, and Davenports, when analyzing forces due to wind load, will be examined. The entire numeric study that is done considers a shear frame of ten stories, reduced to one degree of freedom by the method of modal superposition, taking the contribution of the first mode as the most significant. If the rotation of the pendulum is small, the linear approach is acceptable, thus it is adopted here. Keywords: structural dynamics; vibration control; tuned mass damper (TMD); semiactive control.

ASSUNTO(S)

amortecedor de massa sintonizado (ams) estruturas structural dynamics controle de vibrações tuned mass damper (tmd) vibration control dinâmica estrutural semiactive control controle semi-ativo

Documentos Relacionados