zeroLengthContact Element

[vesna]

if you post your model I can try to run it. If your model is too big it might be difficult for me to find the error.

[civilso]

thanks.i 'll send it to your email.

[vesna]

Just add

model basic -ndm 2 -ndf 3;

before you define your load pattern

[civilso]

I SENT MY PROBLEM TO YOUR EMAIL .
SONA

[civilso]

Hi vesna,
I have used zero contact element in my model that's multi stories.
It has this error:
WARNING -- NDM = 2 and NDF = 2 not compatible with beamColumn element
In one story model ,didn't have this error but when I increase the story, It has this error.
What is my problem?

[vesna]

It looks like you are trying to define beam-column elements while in NDM = 2 and NDF = 2 domain.

Make sure to define all elements that have 3 dofs in NDM = 2 and NDF = 3 domain and then all elements that have 2 dofs in NDM = 2 and NDF = 2 domain.

[civilso]

Hi vesna
1-What is the kt and kn in zero contact element ?are they related to sides of element?
Would you please make an example about the kt and kn?
2- what is the range of mu?

[vesna]

This is contributed element that I never used so I do not have answers for your questions.

Here you will find more information about the element, references and whom to contact with element specific questions:
http://opensees.berkeley.edu/WebSVN/fil ... ontact2D.h

[civilso]

Thanks for your link but last days you sent me an example about zero length contact element.
How do you calculate the " kn=1e5" and "kt=0.5e5 "in this example?
Here is your example:

wipe;
file mkdir Data;

model basic -ndm 2 -ndf 3;
#nodes
node 1 0 0;
node 2 0 10;
node 3 0 10;
# Single point constraints -- Boundary Conditions
fix 1 1 1 1 ;
fix 3 1 1 1 ;
#mass
mass 2 100 100 10e-10;

# Define ELEMENTS -----------------------------------------------------------
geomTransf Linear 1;
element elasticBeamColumn 1 1 2 0.01 3.29e10 1.0e-5 1;

#contact element
model basic -ndm 2 -ndf 2;
node 12 0 10;
node 13 0 10;

equalDOF 3 13 1 2;
equalDOF 2 12 1 2;

element zeroLengthContact2D 3 12 13 1.0e+5 0.5e+5 0.5 -normal 0 1


# Define RECORDERS ---------------------------------------------------------
recorder Node -file data/nodevel.out -time -node 2 -dof 1 vel;
recorder Node -file data/nodeDisp.out -time -node 2 -dof 1 disp;
recorder Node -file data/nodeaccel.out -time -node 2 -dof 1 accel;

# define load and analysis -----------------------------------------------------------
set dt 0.02;
set Scale 1.0;
set accelSeries "Path -filePath A10000.acc -dt $dt -factor [expr 1*$Scale]";
pattern UniformExcitation 1 1 -accel $accelSeries;

constraints Penalty 10e15 10e15;
numberer RCM;
system BandGeneral;
test NormDispIncr 1.0e-6 100
algorithm Newton
integrator Newmark 0.5 0.25;
analysis Transient;

set tFinal [expr 2000 * 0.02];
set tCurrent [getTime];
set ok 0;
while {$ok == 0 && $tCurrent < $tFinal} {
set ok [analyze 1 0.002]
if {$ok != 0} {
puts "regular newton failed .. lets try an initail stiffness for this step"
test NormDispIncr 1.0e-6 100
algorithm ModifiedNewton -initial
set ok [analyze 1 0.002]
if {$ok == 0} {puts "that worked .. back to regular newton"}
test NormDispIncr 1.0e-6 100
algorithm Newton
}
set tCurrent [getTime]
}
# Print a message to indicate if analysis succesfull or not
if {$ok == 0} {
puts "Transient analysis completed SUCCESSFULLY";
} else {
puts "Transient analysis completed FAILED";
};
puts "Done!"

[vesna]

I just assigned random values to kn and kt. The purpose of this example was to demonstrate how to build elements in different domains.