How to model seismic wave propagation

Asked by Huang peilun on 2020-11-03

Hi,

I want to model seismic wave propagation in granular soil. However, I didn't find many examples. I find the method in [1] interesting, but I don't know how to apply this method in Yade.

In [1], soil response to sinusoidal motions in a dry granular soil column is investigated. The concept of viscous boundary developed by Lysmer et al. [2] and White et al. [3] is implemented at the base. This kind of dynamic boundary utilize dashpots attached independently to the boundary for two functions: (1) applying the base input motion to the soil deposit, and (2) absorbing all or part of elastic energy of the shear wave approaching the boundary. To have an absorbing boundary at the base, a frictionless wall was placed to the base of the deposit. The upper boundary is free. Periodic boundaries were employed to simulate a semi-infinite system in the two lateral directions of shaking. At each time step, particles in contact with the base wall were identified. External force promotion to the velocity of each particle in the direction of shaking was applied at the center of the particle in order to simulate the input seismic wave.

My questions are as followed:

1.
In Yade, I find that the periodic boundary must contain all the six faces, including the lateral boundary, the base and the top. (Am I right?) How can I make the base to be a frictionless wall and the upper boundary to be free?

2.
Is there a better way to simulate seismic wave propagation in granular soil? How to deal with the dynamic boundary setting and the input of seismic waves?

Thanks!

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[1]Zamani N, El Shamy U. Analysis of wave propagation in dry granular soils using DEM simulations[J]. Acta Geotechnica, 2011, 6(3): 167.
[2]Lysmer J, Roger L, Kuhlemeyer A (1969) Finite dynamic model for infinite media. J Eng Mech Div 95:858–877
[3]White W, Villiappan S, Lee IK (1977) Unified boundary for finite dynamic models. J Eng Mech Div 103(5):949–964

Question information

Language:
English Edit question
Status:
Solved
For:
Yade Edit question
Assignee:
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Solved by:
Jan Stránský
Solved:
2020-11-05
Last query:
2020-11-05
Last reply:
2020-11-03

This question was reopened

Best Jan Stránský (honzik) said : #1

Hello,

please read [1] and next time try to ask one problem per one question.

Concerning problem 1, just enlarge the periodic cell size in one direction.
See e.g. example video [2] and corresponding example script [3]

cheers
Jan

[1] https://www.yade-dem.org/wiki/Howtoask
[2] https://www.yade-dem.org/wiki/Miscellaneous_videos
[3] https://gitlab.com/yade-dev/trunk/-/blob/master/examples/PeriodicBoundaries/periodicSandPile.py

Huang peilun (hpl16) said : #2

Thanks Jan Stránský, that solved my question.