[MOAB-dev] Question about TRIs and TETs

[Tim Tautges]

Hi Graeme,
   Can you describe strictly in mesh terms (w/o implementation details) what you're trying to do?  From your 
description, I'm uncertain whether you're trying to a) split one face into two, each seeing one of the tets bounded by 
the original, or b) split one edge into two edges, at the same time splitting the connected tris and tets to maintain a 
conformal mesh.  Once you've described that, we can talk about how that should be implemented on top of MOAB.

Thanks.

- tim

On 06/27/2012 08:43 AM, Graeme Edwards wrote:
> Hi there,
>
> I am currently working on a Finite Element problem involving discrete fracture at the University of Glasgow.
>
> For the last few months I have been working on a crack insertion algorithm.  However, I am wondering if I could ask
> for some assistance on a particular problem which I will try and explain as best as I can.
>
> I test the tractions crossing the boundary between 2 elements and if these tractions are greater than some value I
> tag the face to be split.  The first this I do when splitting the faces in split the mid-nodes of the edges of the
> face (I am using higher order elements).  When I am doing this I use MOAB to find all adjacent 2D faces to the 1D
> edge.  I then create a new node and this node is inserted into the new connectivity for the 2D face over the old, or
> original, node.  This is done for every face that is connected to the edge.  This obviously introduces the problem
> that there can be 2 2D faces adjacent to the 1D edge that can lie on the same 3D tetrahedron.  So I was wondering if
> there is anyway to use MOAB to have both of these new nodes in the connectivity of the 3D tetrahedron so that using
> functions I can get the connectivity of the 2D faces?
>
> Regards
>
> Graeme
>
> PS. If that sounds a bit muddled or confused don't hesitate to get in touch with questions before responding.
>
>
> --------------------
>
> Graeme A. Edwards
>
> PhD Student - Materials & Mechanics Research Group
>
> School of Engineering
>
> University of Glasgow Rankine Building Oakfield Avenue G12 8LT
>

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              Tim Tautges            Argonne National Laboratory
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