Using twoNodeLink Element

[naba077]

Dear all,
Here I have a simple model in which I apply the force at one node and wanted to get the moment(=Force * Dist) at the other node but got no results. I use twoNodeLink Element to define the elastic spring and damper. Here I put my coding. Please correct me.


for {set n 1} {$n < 5} {incr n} {
wipe

#Build Model
model basicBuilder -ndm 3 -ndf 6

#Define nodes
node 1 0 8 0
node 2 0 0 0

#Base system
set k 1; #Spring
set c 1; # Damper
set m 1; #mass

# Very small Quantity
set U 1.e10
set u [expr 1./$U]

#Boundary Conditions
fix 1 0 1 1 1 1 1
fix 2 1 1 1 1 1 1

#Define Mass
mass 1 $m $u $u $u $u $u
mass 2 $u $u $u $u $u $u

# Materials Parameter & Element Connectivity
uniaxialMaterial Elastic 1 $k
uniaxialMaterial Viscous 2 $c 1.
uniaxialMaterial Parallel 3 1 2
element twoNodeLink 1 1 2 -mat 3 -dir 1 -orient 1 0 0 0 1 0 -pDelta 0 1 0 1


# Define Records --------------------------------------
recorder Node -file d_Node2f$n.out -time -node 2 -dof 6 reaction; # Resp Moment

#Define Time Series
timeSeries Trig 1 0.0 50.0 [expr 1./($n/10.0)]

pattern Plain 1 1 {
load 1 1.0 0.0 0.0 0.0 0.0 0.0
}

#dynamic analysis
integrator Newmark 0.5 [expr 1./6.]
test EnergyIncr 1.0e-12 20 1
algorithm Linear
numberer Plain
constraints Plain
system BandGeneral

analysis Transient
analyze 50000 0.001
}

[vesna]

I've noticed several things:

1. You can not use the viscous material in the way you have intended. Read notes here: http://opensees.berkeley.edu/wiki/index ... s_Material
2. Your two node link element is vertical (direction Y), but your spring is horizontal. Make sure that is what you wanted.
3. Load should be applied using "sp" command
4. Penalty constraints need to be used