There are different types of surface acoustic waves. Presumably, the most wide spread are Rayleigh, Lamb, Love, SH, and Stoneley waves. Roughly, each type needs in different modeling technique.
Dear Sergey Kuznetsov,
What about Rayleigh surface waves, If you could explain, how we can model it?
Thank you
Dear All,
In case someone still follow this question, I asked this question long ago and during my PhD studies solved this question.
In order to generate surface acoustic or surface Rayleigh wave with vertical excitation component, following are some tips.
1. Surface waves exist at the surface of a semi-infinite half space, in order to observe such wave propagation, semi-infinite medium is mandatory.
2. If you are in COMSOL, you may use point load/prescribed displacement as an point for harmonic excitation either in frequency domain or time transient studies. Similarly, you can use applied load condition in ANSYS or Abaqus to do so.
3. For surface acoustic wave/Rayleigh wave, excite z-component/out-of-plane component (2D model) and in case of 3d model, induce excitation in x and z direction. For love wave or shear horizontal surface wave, excite the x and y component of load/prescribed displacement.
4. Use PML (perfectly matched layer) or low reflection boundary (LRB) at the both ends and bottom of the infinite half-space. This will avoid the back-reflection of incident waves from boundaries and ensure surface wave propagation at the semi-infinite surface.
Further details can be find in my papers given below. Pls do cite my work if you find them helpful. You can also visit my profile for more updated works in this realm. I am also attaching my YouTube video for better visualization.
Article Built-up structural steel sections as seismic metamaterials ...
Article Surface Elastic Waves Whispering Gallery Modes based Subwave...
Article Forest Trees as Naturally Available Seismic Metamaterials: L...
https://www.youtube.com/watch?v=4Exl6ND_R5U
https://www.youtube.com/watch?v=EoWmAiwRa3g
Cheers!
Regards,
Muhammad
The simplest method to generate Rayleigh waves is to (dynamically) apply a vertical force inside a halfplane (that is known, as the inner Lamb problem).
I am not familiar with Comsol, however, the code for Abaqus 6.14, can be found here (DOI: 10.13140/RG.2.2.29924.40321) and the plot for arrivals of bulk P and S waves, evanescent SP wave and Rayleigh (R) wave is here (DOI: 10.13140/RG.2.2.23528.08963)
See also the relevant paper (DOI: 10.3103/S0025654415050039)
Hi,
In this case you must be utilize Piezoelectric physic to generate like a love wave. If you want I can telling you.
Sincerely
There is an example in comsol. The SAW is generated on Piezoelectric substrate.
You may use prescribed displacement on an edge for a line source or on a point if a point source is neccessary. But before this step, a work place should be created and patitioned. I do this in the solid mechanics module.
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