[CIG-SHORT] Fwd: a question on pylith

[shi chen]

Hi Brad and Charles,

Thanks for your good reply. I think the density change is also related to
the stress perturbation. And the small strain coupling with the density
change will need to estimate and renew in each step duo to the
gravitational force. Please see this attachment for short mathematical
description.
For the gravity change, I have the code to compute and achieve this aim in
the post-processing.

Best regards!

Shi


2013/11/12 Charles Williams <willic3 at gmail.com>

> As a follow-up to Brad's response, the infinitesimal strain approximation
> (default) does not include the effects of density changes due to volume
> change, but the small strain model does include these effects.  The small
> strain model includes geometrical nonlinearity, and is thus a nonlinear
> model.  You will be able to calculate density changes, but PyLith does not
> do gravitational calculations.  You would need to first compute the density
> changes with PyLith, and then use a gravity code to compute the gravity
> changes.  I hope this helps.
>
> Cheers,
> Charles
>
>
> On 12/11/2013, at 3:53 PM, Brad Aagaard wrote:
>
> Shi,
>
> PyLith solves the elasticity equation (see the manual for details on the
> governing equations). Using the small-strain formulation, the effects of
> changes in the geometry associated with deformation will change the
> resulting gravitational loading. Calculating any resulting changes in the
> geoid from the deformation would require post-processing with your own
> code. If I am misunderstanding your questions, please send a more
> mathematical description of what you want to do.
>
> Regards,
> Brad
>
>
>
>
> On 11/11/13 1:54 PM, shi chen wrote:
>
> Hello,
>
>
> From the CIG website, I know the pylith software can simulate tectonic
>
> deformation problems. I am very interest in the pylith. But I want to
>
> know that PyLith is eligible to simulate the density change due to the
>
> elastic/viscoelastic compressible model or not? I want to simulate the
>
> force perturbation due to dilatation with the defined multi density
>
> layer model. And further to calculate the gravity change with the
>
> density change.
>
>
> Thanks for your help!
>
>
> Best regards!
>
>
>
>
>
> Shi CHEN
>
> Visiting Schloar
>
> University of Missouri-Columbia
>
> Department of Geological Sciences
>
> 101 Geology Building
>
> Columbia, MO 65211-1380
>
> chenshi80 at gmail.com <mailto:chenshi80 at gmail.com <chenshi80 at gmail.com>>
>
>
>
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>
>  Charles A. Williams
> Scientist
> GNS Science
> 1 Fairway Drive, Avalon
> PO Box 30368
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>
>


Shi CHEN
University of Missouri-Columbia
Department of Geological Sciences
101 Geology Building
Columbia, MO 65211-1380
chenshi80 at gmail.com
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