Estudo de estruturas periódicas para aplicações em isolamento de vibrações pela base

Abstract

Seismic activity has the potential creating enormous devastation in the civil construction field. In doing so, active, semi-active, hybrid, and passive control systems have been developed over time to prevent structural collapse during these events. Recent research conducted by different authors has shown that periodic structures (PS) can potentially be used for passive seismic vibration control through base isolation. In summary, a PS is formed from the repetition of alternating layers with different geometrical and/or physical properties along its length. The wave filtering effect developed by a PS through the formation of frequency intervals, known as Band Gap, enables its application in different engineering fields. In this paper, periodic structures are modeled by the spectral element method, using the bar element formulation and the Euler-Bernoulli beam elements. A numerical study is conducted to evaluate the Band Gap formation of a PS at low frequency, subjected by longitudinal and flexural waves, based on different types of periodicity. In sequence, a case study is developed to investigate the application of a PS in seismic isolation, taking existing solutions as a reference. The coupled model of a periodic structure connected to a flexible structure is also developed, allowing to visualize the dynamic behavior of the assembly. At last, the methodology is validated through experimental results based on transmissibility curves and frequency response functions.