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Regular meshing

Posted: Fri Feb 06, 2015 4:35 pm
by taherghazvini
how can i generate regular meshing when i have curve and rectangular surfaces together?
i want to use quadrilateral elements for modeling one solid body (half cylindrical hollow foundation) in another solid body (soil medium) with different number of nodes in same coordinates. this should be use in opensees code (tcl code) for considering soil structure interaction with using brick elements (8 nodes element).

Re: Regular meshing

Posted: Fri Feb 06, 2015 4:58 pm
by abelcs
I'm not sure I've understood well you. May be you are asking to use the so called ContactVolumes. This entities ensures you have a relationship one-to-one between two surface meshes.
You can see how they are created in help: Geometry->Create->Contact.

Re: Regular meshing

Posted: Fri Feb 06, 2015 5:37 pm
by escolano
It seems that do you have an axial-symmetrical model, and probably the 3D model is reduced to a 2D model, and do you want to have two neighbor surfaces that will be meshed with quadrilaterals, and do you require that each quadrilateral on the common line have its own nodes (but located in the same position for both surfaces).
In this case do you have two options:
1) Modify the geometry, creating a line for each surface, avoiding share any line.
If now lines are shared you can duplicate them with Geometry->Edit->Uncollapse surfaces, and select them.

And then each line will have its own nodes, and do you probably need to force being in the same location for both surfaces. You can do it for examply:
1.a) assigning the same number of structured divisions.
1.b) creating a 'contact surface' between both lines, this force a one-to-one relationship (you can force not to mesh this additinal contact surface entity, to avoid its extra elements)

2) Have a shared common curve in the geometry, and do this 'nodes duplication' at meshing time, with
Mesh->Mesh criteria->Duplicate->Lines (and select the shared lines to duplicate its nodes)

Probably the second approach is easier, specially with complicated model.
The same aproachs could be applied if your case is 3D (but the trick to assign a number of divisions to a line, in 3D this is similar to create a structured mesh of the common surface, and this is not always possible in a trimmed surface)

Re: Regular meshing

Posted: Sun Feb 08, 2015 3:41 pm
by taherghazvini
First of all, I would like to state the gratitude for your kind reply. I am planning to build up 8-noded quidrilateral mesh discritization for my numerical model.
Even though I understand in GID- structural mesh part, it is possible to generate either uniform mesh or structural mesh along with refinement part in sub-section of preferences-meshing, but my attempts to form a mesh descriztization were unsuccessful. I would be grateful if you kindly give me your email for sending you the geometry for better understanding the issue.
I wonder if i can model the shallow foundation with separate nodes from the surrounding soil nodes (i.e., I mean two different mesh generation for foundation and soil).