Beam-Column Element and Quad Element in the same analysis

[WAELL]

Hello all;
I am a new user of OpenSees Program. I would like to use 2D Beam-Column Elements (3 DOF per node) with Quadrilateral Elements (2DOF per node).

When I use
model basic -ndm 2 -ndf 3
I got
Warning – model dimentions and/or nodal DOF not compatible with quad element

And when I use
model basic -ndm 2 -ndf 3
model basic -ndm 2 -ndf 2
I got
Warning – NDM = 2 and NDF = 2 is imcompatible with available frame elements

Does anybody know how to involve Beam-Column Elements and Quadrilateral Elements in the same analysis?

Thanks in advance

[silvia]

some have done it, you should search for the thread.

[WAELL]

There was a similar post by Timosidis on May 26, 2005 (page 2), and a reply by Berktaftali. But Berktaftali’s reply was not completed. I tried to e-mail Timosidis, but his e-mail is not valid any more.
One of the replies was “Take a look at solid02.tcl file in Example Scripts, it does what you need”, but unfortunately I did not find it.
Please advice

[fmk]

it's not the quad .. here is an example mixing nodes with 2 and 3 dof in 1 model
.. it's only an example (as you can use beams and trusses in a model with 3 dof
at a node) .. however you should easily be able to use it to mix quad 2dof and beams
3dof elements.

# Example: quick example on how to mix elements with differing DOF.
# for demo purposes only, as you can use truss with rotation dof present.

# created: fmk 08/08/05

# Set parameters for overall model geometry
set width 360
set height 144

# Create ModelBuilder (with two-dimensions and 3 DOF/node)
model basic -ndm 2 -ndf 3
node 1 0.0 0.0
node 2 $width 0.0
node 3 0.0 $height
node 4 $width $height
fix 1 1 1 1
fix 2 1 1 1
geomTransf Linear 1
element elasticBeamColumn 1 1 3 360 4030 8640 1
element elasticBeamColumn 2 2 4 360 4030 8640 1
element elasticBeamColumn 3 3 4 360 4030 8640 1
pattern Plain 1 "Linear" {
load 3 100.0 -20.0 0.0
load 4 100.0 -20.0 0.0
}

# Create another ModelBuilder (with two-dimensions and 2 DOF/node)
model basic -ndm 2 -ndf 2
node 11 0.0 0.0
node 12 $width 0.0
node 13 0.0 $height
node 14 $width $height
fix 11 1 1
fix 12 1 1
uniaxialMaterial Elastic 1 100.0
element truss 4 11 14 10.0 1
element truss 5 12 13 10.0 1

# now force nodes 13 and 14 to hve same disp as 3 and 4.
equalDOF 3 13 1 2
equalDOF 4 14 1 2

# perform an analysis
system BandGeneral
constraints Transformation
numberer RCM
test NormDispIncr 1.0e-12 10 3
algorithm Newton
integrator LoadControl 1
analysis Static
analyze 1

# print the results
print node 3 4 13 14

[WAELL]

Thanks Frank