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Resonance blocking and passing effects in two-dimensional elastic waveguides with obstacles
Evgeny Glushkov1, Natalia Glushkova, Mikhail Golub
1Institute for Mathematics, Mechanics and Informatics, Kuban State University, Krasnodar, 350040, Russia. evg@math.kubsu.ru
The Journal of the Acoustical Society of America
|July 27, 2011
Summary
Wave energy trapping in 2D waveguides with obstacles blocks propagation. However, multiple obstacles can create narrow bands for wave passage, unlike single obstacles which act as blockers.
Area of Science:
- Wave mechanics
- Acoustics
- Solid mechanics
Background:
- Resonance localization of wave energy in two-dimensional (2D) waveguides with obstacles, termed the trapped mode effect, impedes wave propagation.
- This phenomenon is intrinsically linked to the positions of natural resonance poles within the complex frequency plane, representing spectral points of the associated boundary value problem.
Purpose of the Study:
- To analyze the blocking and passing effects of wave propagation in a 2D elastic layer containing defects.
- To investigate how the number and arrangement of obstacles influence wave transmission characteristics.
Main Methods:
- Development and application of a semi-analytical model for wave propagation analysis.
- Examination of spectral points (resonance poles) in the complex frequency plane.
- Analysis of transmission coefficient plots in relation to defect configurations.
Main Results:
- Multiple obstacles increase the number of resonance poles, influencing wave propagation.
- While single obstacles block wave propagation, multiple obstacles can open narrow transmission bands near real spectral poles.
- The positioning of defects affects pole locations but generally maintains transmission gaps within similar frequency ranges.
Conclusions:
- A combination of scatterers can be strategically used to broaden transmission gaps.
- The study reveals a transition from wave blocking by single obstacles to wave passage in narrow bands with multiple obstacles in 2D waveguides.
- The findings offer insights into controlling wave propagation through engineered defects in elastic layers.
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