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Elastic Waves with SPH

  1. Jun 17, 2013 #1
    Hello Everyone,

    I'm trying to solve the following Problem:
    (taken from "SPH simulation for seismic behavior of earth structures" - Y.Ono et. al)

    To this end, I wrote a small matlab skript, to be found here. The paper presents results at t=10s and t=20s:

    which my solution reproduces quite accurately if i set kh (the ratio from particle spacing to smoothing length) to 1:
    (snapshot taken at t=20)

    However, as soon as I increase kh the solution quickly deteriorates:
    (kh=2, snapshot taken at t=5).

    Currently, I think that this is due to the boundary deficiency of SPH. That is, increasing h will lead to larger deficient boundary regions like so:
    reconstruction of the derivative of a sine function, top with kh = 2, bottom with kh=8. Code.

    I already tried to:
    - assign densities according to 7b622d669cbc463c46aee50d6a54de51.png
    - adapt h according to h_p = h_init*(rho_init/rho_p), using the densities computed with the formula above
    - introduce CSPM corrections (even though the paper clearly states that the problem should be solvable employing "vanilla" sph only).

    I would be very grateful for any input.

    PS: I hope this is the right subforum

    EDIT: In case anybody was wondering about the kernel
    Last edited: Jun 17, 2013
  2. jcsd
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