Phononic Local Resonances of Lamb Waves in a Plate with Periodic Stubbed Surface
Date Issued
2007
Date
2007
Author(s)
Tsai, Tzu-Chin
DOI
en-US
Abstract
In this thesis, the phononic local resonances of lamb waves in a plate with periodic stubbed surface are simulated and analyzed. The calculations of dispersion curves of these active structures are conducted with the help of the finite element method (FEM). Numerical examples are obtained for a square lattice of columns grown on a steel slab. It is found that several complete band gaps with a variable bandwidth exist for elastic waves. We found that the key parameter for the existence position and width of these complete band gaps is the ratio about the columns height, h, and the slab thickness, d.
Secondly, the phenomena of standing wave modes in phononic crystal structures are discussed and analyzed. According to the cavities set on the phononic crystal structures, some standing wave modes are located in the band gap. When the standing wave modes are located in band gaps, local resonances are occurred.
Finally, some applications of local resonances are designed because the dispersion curves and displacement fields are simulated. This advantage can be used to mix or vibrate in high frequency. In microanalysis, this method can be used to accelerate the reactions of liquids.
Subjects
聲子晶體
有限元素法
正方晶格
頻溝現象
板波
駐波模態
局部共振
Phononic crystal
Finite element method
Square lattice
Band gap
Lamb wave
Standing Wave Mode
Local Resonances
Type
thesis
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