[CIG-SHORT] Dynamic rupture on realistic mesh

[Huihui Weng]

Hi Brad,

Thanks very much. I will try it as your suggestions.

Best,
Huihui

> On 10 Nov 2017, at 2:38 AM, Brad Aagaard <baagaard at usgs.gov> wrote:
> 
> Huihui,
> 
> In a 3-D simulation with a 2-D fault surface and spontaneous rupture, slip occurs in the direction of the current shear traction vector. Even if you apply initial shear tractions in only one direction, the dynamic shear tractions may be large enough to cause slip to be in a slightly different direction. Dynamic stress changes are affected by spatial variations in elastic properties, nonplanar fault geometry, and discretization error associated with coarse or distorted cells.
> 
> The first thing I would do is to run a problem with the same parameters and a planar fault. You should check the mesh quality, nondimensionalization scales, and how well resolved the solution is by running at a few different resolutions.
> 
> Once the planar fault produces good results, then start increasing the roughness (nonplanar geometry) of the fault. Start with a very smooth fault and then gradually work your way to the desired roughness. If you have significant curvature in the fault surface, you may need to increase the resolution of your mesh in those areas. You should be able to identify those areas with careful analysis of the solution as you increase the roughness and evaluate multiple resolutions. As we point out in our tutorials, you should consider the uncertainty and resolution of the observations that you are trying to model when deciding on the length scales to include in your model. For example, we know the topography of Earth's surface very well, but we usually don't need a high resolution discretization of topography in our models due to much larger uncertainties in geometry and properties at depth.
> 
> Regards,
> Brad
> 
> 
> 
> On 11/08/2017 10:02 PM, Huihui Weng wrote:
>> Hi Brad,
>> I have rerun this case by single computer core. In this situation, the progress will abort with error: RuntimeError: WARNING! Fault opening with nonzero traction., v_fault: 7990, opening: 1.0026e-07, normal traction: -0.00370101. Please see the attached file for detailed log.
>> The most important problem I concern about is why the normal and strike slips always accompany with the dip slip in the curved fault, even only assigning the shear stress at the dip direction. How can I inhibit these unnecessary slip? Could I do it by adjust the parameters of PETSc? Thanks.
>> Best,
>> Huihui
> 
> _______________________________________________
> CIG-SHORT mailing list
> CIG-SHORT at geodynamics.org
> http://lists.geodynamics.org/cgi-bin/mailman/listinfo/cig-short