新型隔減震技術：共振筒形地震超材料
Other Title
New Seismic Attenuation Technology: Resonator-Type Metamaterial
Journal
結構工程
Journal Volume
39
Journal Issue
1
Start Page
103
End Page
125
ISSN
1021-7878
Date Issued
2024-03
Author(s)
Abstract
地震超材料（seismic metamaterial）為全新之抗震技術，透過人造結構改變波傳行為，產生特定頻率之波傳無法通過的區域，防止具高破壞性頻率的地震波傳至結構物，達到保護結構物效果。目前地震超材料面臨兩大困難：（1）超材料帶隙頻率相較於地震主頻過高；（2）缺少針對體波的地震超材料。有鑑於此，本研究藉由Kalderon等人所提出的雙層質量共振筒公式，設計新型的低頻率（0.35-1.5 Hz）、針對體波的地震超材料單元，並以數值模擬方法確認其折減效益。首先以單元晶格頻散分析確定帶隙範圍。同時進行排數分析及排序分析確認產生折減效果所需的超材料單元數及最佳排列方式，顯示所設計的超材料單元四個為一組，為最經濟之排列方式。此外，探討超材料外側土壤厚度對折減效益的影響，並接續透過地盤反應分析，確認超材料在實際地震下對SH波的折減效益容易受到側向土體量影響，但側向土體量對P波下的折減效益則不顯著。最後，真實地震下反應分析顯示超材料單元在實際地震P波與SH波激發下，可折減超材料帶隙對應週期之結構物譜加速度至原本的一半，顯示目前設計的共振筒型超材料具備發展潛力。
Seismic metamaterials represent a novel earthquake-resistance technology. By manipulating wave propagation through artificial structures, they create regions where waves of specific frequencies cannot pass, preventing seismic waves of primary frequencies from reaching structures. Currently, seismic metamaterials face two major challenges: (1) the band gap frequency of the metamaterial is relatively higher than the primary frequency of earthquakes, and (2) there is a lack of metamaterials specifically designed for body waves. In light of this, our study designs a new low-frequency (0.35-1.5 Hz) seismic metamaterial unit targeting body waves based on dual-layer tube-type resonators. Row and ordering analyses were conducted to determine the optimal arrangement of metamaterial units for reduction effects. The influence of the soil layer outside the metamaterial on its reduction effect was also investigated. Simulation results show that a group of four consecutive metamaterial units is the most economical arrangement, and the reduction effect of the metamaterial on SH waves was sensitive to the thickness of the soil layer. A subsequent ground response analysis demonstrated that when excited by actual seismic waves, the designed metamaterial units can reduce the spectral acceleration at the corresponding metamaterial band gap period to half, indicating the promising potential of the dual-layer tube-type resonators.
Subjects
地震超材料
有限元素法
局部共振
帶隙
seismic metamaterial
finite element analysis
local resonance
bandgap
Type
journal article