How to apply a displacement on rigidlink node?

[hjxiang]

Hi, everybody,

I want to apply a displacment at a node of rigidlink, but I didn't get any right results. The reaction force is zero. Why? How to do this? Thanks.
My sample script is as follows:

wipe;
model basic -ndm 2 -ndf 3
# nodal coordinates:
node 1 0 0.0
node 2 0 1.0
node 3 0 2.0
node 4 0 3.0

# bondary conditions:
fix 1 1 1 1

# transformation:
geomTransf Linear 1

set E 21.0e10;
set B 0.04;
set H 0.06;
set A [expr $B*$H];
set Iz [expr $B*$H*$H*$H/12.0];
# element connectivity:
element elasticBeamColumn 1 1 2 $A $E $Iz 1;
element elasticBeamColumn 2 2 3 $A $E $Iz 1;
rigidLink beam 4 3;

# recorders
recorder Node -file Node4.out -time -node 4 -dof 1 2 disp
recorder Node -file Node3.out -time -node 3 -dof 1 2 disp
recorder Node -file reaction4.out -time -node 4 -dof 1 2 reaction

#
pattern Plain 1 Linear {
sp 4 1 0.01;
}
#
constraints Transformation
numberer RCM
system BandGeneral
test NormDispIncr 1.0e-6 6
algorithm KrylovNewton;

integrator LoadControl 0.1;
#integrator DisplacementControl 4 1 0.001;
analysis Static

analyze 10

[vesna]

For the purpose of your model i think it is better to replace rigid link with a very rigid elastic element. If you know the properties of the rigid elements use them. Otherwise, assign very high area and moment of inertia to this element.

[hjxiang]

Thank you, vesna.


vesna wrote:
> For the purpose of your model i think it is better to replace rigid link
> with a very rigid elastic element. If you know the properties of the rigid
> elements use them. Otherwise, assign very high area and moment of inertia
> to this element.