How can I use different types of elements simultaneously?
For example, Quad elements with 2 DOFs per node (ux & uy) and 2D elastic BeamComlumn elements with 3 DOFs per node (ux, uy & rz) can be used together?
If there is any example, it will be helpful for my understanding.
Using different types of element
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bayram_aygun
- Posts: 109
- Joined: Sat May 05, 2007 12:28 pm
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Pasting the answer Matt Bowers gave long time ago.
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You must create your 2D 2DOF Soil mesh first. You probably will want to apply gravity for the soil before creating your pile. Then call up the 2D 3DOF model builder and create your pile. You may then use equalDOF command to connect pile (with 3DOF) to soil mesh (with 2DOF) in the x and y directions.
If you are using springs to model nonlinear Soil Structure Interaction, dummy nodes are required in 2DOF space. The dummy nodes are connected to soil via spring elements. The 2DOF dummy node is then slaved to pile nodes using equalDOF.
Hope this helps,
Matt Bowers
Clemson University
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You must create your 2D 2DOF Soil mesh first. You probably will want to apply gravity for the soil before creating your pile. Then call up the 2D 3DOF model builder and create your pile. You may then use equalDOF command to connect pile (with 3DOF) to soil mesh (with 2DOF) in the x and y directions.
If you are using springs to model nonlinear Soil Structure Interaction, dummy nodes are required in 2DOF space. The dummy nodes are connected to soil via spring elements. The 2DOF dummy node is then slaved to pile nodes using equalDOF.
Hope this helps,
Matt Bowers
Clemson University
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Bayram Aygun
Graduate Student, Civil&Env. Eng.
Rice University
Graduate Student, Civil&Env. Eng.
Rice University
different model builders
Hi,
I had a similar problem some time ago. The idea of defining more than one model builder was strange to me, but i tried it out and it worked. I think the only thing, that is important is that dof for the first model builder has to be smaller than for the second one. (not quite sure about that). I am posting an example, hope it helps.
I had a similar problem some time ago. The idea of defining more than one model builder was strange to me, but i tried it out and it worked. I think the only thing, that is important is that dof for the first model builder has to be smaller than for the second one. (not quite sure about that). I am posting an example, hope it helps.
Code: Select all
# example
# ndf 3 element----ndf 6 elements -----ndf 3 element
# 1 22(2) 3 4 (5)55 6
# |o@o------o------o-------o@o| o...nodes
#
# first model builder
model basic -ndm 3 -ndf 3; # 3 dimensions, 3 dof per node
node 1 0 0 0;
node 22 0 0 0; # dummy node (same as node 2 later)
node 6 15 0 0;
node 55 15 0 0; # dummy node (same as node 5 later)
# constraints
fix 1 1 1 1;
fix 6 1 1 1;
# some ndf 3 elements...
#eg. zerolength between 1 and 22 and 8 and 77
element...
# second model builder
model basic -ndm 3 -ndf 6; # 3 dimensions, 6 dof per node
node 2 0 0 0;
node 3 5 0 0;
node 4 10 0 0;
node 5 15 0 0;
# equal dof anything you need, for example.
equalDOF 2 22 1 2 3 4 5 6 ; # equal dof dummy nodes
equalDOF 5 55 1 2 3 4 5 6; # equal dof dummy nodes
#... rest of the code for ndf 6Zlatko Vidrih
Institute of Structural Engineering, earthquake Engineering and Construction IT
Faculty of Civil and Geodetic Engineering
University of Ljubljana, Slovenia
Institute of Structural Engineering, earthquake Engineering and Construction IT
Faculty of Civil and Geodetic Engineering
University of Ljubljana, Slovenia