[CIG-SHORT] Mesh interpenetration

[Li, Teng]

Hi Matt,

Please find the attachment which is the original mesh in the area where the left 60 degrees secondary fault link directly to the main fault. Two faults are highlighted. As we can see, all the mesh in this area is quad mesh. The reason why we see the triangular mesh in the left part is just that some meshes overlap each other. And according to my observation, part of the cells along the secondary fault on the right go into the cells along the secondary fault on the left part.

Because the left 60-degree secondary fault link directly to the main fault, there will be a sharp triangular in the junction area. I choose 12.5m mesh size and use Trellis to mesh this area. And please find the new attachment for the mesh information in this junction triangular area. If this mesh is in a bad quality, what might be the solution? Can I use smaller mesh size?

Thanks.

Best,
Teng


Teng Li

Master Candidate in Structures

Department of Civil and Environmental Engineering

University of Illinois at Urbana-Champaign

205 North Mathews Ave, Urbana, IL. 61801

Phone:(217)8196210, Email: tengli2 at illinois.edu



________________________________
From: CIG-SHORT [cig-short-bounces at geodynamics.org] on behalf of Matthew Knepley [knepley at rice.edu]
Sent: Wednesday, November 01, 2017 3:14 AM
To: cig-short at geodynamics.org
Subject: Re: [CIG-SHORT] Mesh interpenetration

On Wed, Nov 1, 2017 at 12:05 AM, Li, Teng <tengli2 at illinois.edu<mailto:tengli2 at illinois.edu>> wrote:
Hi,

Please see the attached picture which shows the junction of the secondary fault and the main fault. I used paraview to visualize the vtk file. In the paraview, I used wrap by vector filter to show the displacement of the junction. As we can see, it seems interpenetration occurs in this area. And two faces separate from each other.  I wonder whether this is a valid result? And if it is not right, what might be the reason? Thanks.

1) I do not understand why there are two triangles in the picture. Isn't this an all quad mesh?

2) If the fault is in tension, it will open. I am not sure why you would call that interpenetration, which means that two quads cross over each other, not leave a void.
     You might increase the cohension at that interface if you want it to remain together, or look at the normal stress on the fault, which should ordinarily be more
     than enough to keep it together.

3) The extremely narrow quads on the right are bad for your system condition number. Why did you mesh it that way?

   Thanks,

     Matt

Best,
Teng


Teng Li

Master Candidate in Structures

Department of Civil and Environmental Engineering

University of Illinois at Urbana-Champaign

205 North Mathews Ave, Urbana, IL. 61801

Phone:(217)8196210<tel:(217)%20819-6210>, Email: tengli2 at illinois.edu<mailto:tengli2 at illinois.edu>



_______________________________________________
CIG-SHORT mailing list
CIG-SHORT at geodynamics.org<mailto:CIG-SHORT at geodynamics.org>
http://lists.geodynamics.org/cgi-bin/mailman/listinfo/cig-short<https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_cig-2Dshort&d=DwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=7Ynh-iTRB5WfWs5PAMUyBc4S6lnZBeUlHmC6_Kxw4OY&m=CHEahnZ1FMBpBBK8WHfa4BAtzaq34AWSc0mSgZZAaCo&s=xLz2rpr4BX-rZ5jU65ma7cyl-QV0hicVxbiGUD1UKPU&e=>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.geodynamics.org/pipermail/cig-short/attachments/20171101/343ea50d/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Original mesh.png
Type: image/png
Size: 76371 bytes
Desc: Original mesh.png
URL: <http://lists.geodynamics.org/pipermail/cig-short/attachments/20171101/343ea50d/attachment-0001.png>