Steel structure with spring between elements

[dcizmar]

I am trying to model spring between the element 6 and element 3 in my model. I added joint 5 and via equalDOF connected it with the joint 3. Then made zerolength element. The spring should carry axial load from element 6. There are several things that bother me.

1. I assigned element zeroLength 7 5 3 -mat 1 -dir 2 but when I print info for element 7 I get dir 1. Am I missing something or there should be dir 2?

2. By looking at the joints 3 and 5 there is difference in vertical displacements which obviously should be, but there is no axial force in element 7???

Here is the code:
---------------------------------------
model BasicBuilder -ndm 2 -ndf 3

set P 100
set l 121.9;
set h 91.44;
set E 20600;
set a1 1.33;
set a2 1.49;
set k 1;
set I 10 ;


node 1 0.0 0.
node 2 $l 0.0
node 3 $l $h
node 4 0 $h
node 5 $l $h

fix 1 1 1 1
fix 2 0 1 1

equalDOF 3 5 1 3

uniaxialMaterial Elastic 1 $E
puts materijal

geomTransf Linear 1

element elasticBeamColumn 1 1 2 $a1 $E $I 1
element elasticBeamColumn 2 2 3 $a2 $E $I 1
element elasticBeamColumn 3 3 4 $a2 $E $I 1
element elasticBeamColumn 4 4 1 $a1 $E $I 1
element elasticBeamColumn 5 4 2 $a1 $E $I 1
element elasticBeamColumn 6 1 5 $a1 $E $I 1

element zeroLength 7 5 3 -mat 1 -dir 2
#orient 0 1 0 -1 0 0

pattern Plain 1 Linear {
load 4 $P 0.0 0.0
#load 4 $G 0.0
}


recorder Element -file 1.txt -load -ele 1 localForce
recorder Element -file 2.txt -load -ele 2 localForce
recorder Element -file 3.txt -load -ele 3 localForce
recorder Element -file 4.txt -load -ele 4 localForce
recorder Element -file 5.txt -load -ele 5 localForce
recorder Element -file 6.txt -load -ele 6 localForce
recorder Element -file 7.txt -load -ele 7 axialForce
recorder Node -file D.txt -time -node 3 5 -dof 1 2 3 disp

constraints Plain
numberer RCM
test NormUnbalance 1.0e-2 250 0
integrator LoadControl 0.025 1 0.025 0.025
algorithm Newton
system ProfileSPD
analysis Static

integrator LoadControl 0.05 3 0.05 0.05
analyze 16
integrator LoadControl 0.02 3 0.02 0.02
analyze 10

print ele 1 7

[fmk]

localForce is not something you could ask from a zeroLength element until current version 2.2.0 .. try force or forces with the version you have.