[CIG-SHORT] Stress concentration near the fault tip

[Brad Aagaard]

Josimar,

Why are you constraining the tangential (z) displacement on the right 
hand side boundary? I think this may be causing the large tractions 
around the fault on the right hand side.

You should not mark the buried edges of the fault on edges of the fault 
that reach the edges of the domain.

Brad


On 11/06/2016 04:31 PM, Josimar Alves da Silva wrote:
> Dear Charles,
>
> Thank you so much for the reply. I am attaching a figure with the
> correct boundary conditions.
>
> My questions is:
>
> 1) What causes the high normal and shear stresses near the fault tip ?
>
> Would it be possible that there is something wrong on the way I am
> parameterizing the fault edge ? I have tried turning on the "edges"
> command on the set up but I still observe the high stresses.
>
> My simulation only runs for 15 years. At the end of the simulation there
> is no fault displacement. However, only the high stress values indicated
> above. I wonder if this behavior is normal because the failure criteria
> was not met ?
>
> Best,
> Josimar
>
>
>
>
>
>
>
> On Sun, Nov 6, 2016 at 1:25 PM, Charles Williams <willic3 at gmail.com
> <mailto:willic3 at gmail.com>> wrote:
>
>     Dear Josimar,
>
>     I am somewhat confused about your boundary conditions.  Are any
>     conditions being placed on the top and bottom boundaries?  Also, it
>     appears that you are applying Neumann BC on the left boundary,
>     rather than the fixed displacement BC shown in your figure.  Is this
>     correct, or is something mislabelled?
>
>     Cheers,
>     Charles
>
>
>>     On 5/11/2016, at 11:24 AM, Josimar Alves da Silva
>>     <jsilva.mit at gmail.com <mailto:jsilva.mit at gmail.com>> wrote:
>>
>>     Dear All,
>>
>>     I am running PyLith with a 2D fault friction model, including
>>     gravitational effects.
>>
>>     I am finding stress concentration near the tip of the fault and I
>>     would like to understand why this occurs. See attached figure.
>>
>>     On the link below Brad seems to address this issue, however it is
>>     still not clear to me why this happens.
>>
>>     http://lists.geodynamics.org/pipermail/cig-short/2014-November/001924.html
>>     <http://lists.geodynamics.org/pipermail/cig-short/2014-November/001924.html>
>>
>>     Details about my simulation are attached (log files, boundary
>>     conditions...)
>>
>>     Thank you in advance for your time.
>>     Best,
>>     Josimar
>>     <pylith_problem.pdf><log.out>_______________________________________________
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>
>     Charles A. Williams
>     Scientist
>     GNS Science
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>
>
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