modeling a 25 bar space truss with different loadings

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assimi
Posts: 17
Joined: Wed Mar 30, 2016 11:16 am
Location: University of Adelaide

modeling a 25 bar space truss with different loadings

Post by assimi »

Hi, I want to model this 25 bar truss benchmark. the schematic of the benchmark and the loading conditions are attached.
How can I define this kind of loading in my code? Because there are multiple loading on nodes 1 and 2. Is it possible with multiple pattern plains? In a one sentence, How can I model this particular loading which is depicted in the picture?

[url]http://pasteboard.co/9rpVSLdj.png[/url]
[url]http://pasteboard.co/feezMfdv7.png[/url]

I tried in this way, but it doesn't work, since the deflection in the nodes should be lower than 0.35 inch.
Any help would be appreciated. THX in advance.

P.S. however it's mentioned that the second load on the node 2 on y-axis should be -2 in the picture, but the correct loading is -20 which I checked in other references.
[code]
wipe
model BasicBuilder -ndm 3 -ndf 3
node 1 -37.5000 0.0000 200.0000
node 2 37.5000 0.0000 200.0000
node 3 -37.5000 37.5000 100.0000
node 4 37.5000 37.5000 100.0000
node 5 37.5000 -37.5000 100.0000
node 6 -37.5000 -37.5000 100.0000
node 7 -100.0000 100.0000 0.0000
node 8 100.0000 100.0000 0.0000
node 9 100.0000 -100.0000 0.0000
node 10 -100.0000 -100.0000 0.0000
fix 7 1 1 1
fix 8 1 1 1
fix 9 1 1 1
fix 10 1 1 1
uniaxialMaterial Elastic 1 10000
element Truss 1 1 2 0.0140 1
element Truss 2 10 3 0.6740 1
element Truss 3 8 3 1.6470 1
element Truss 4 7 3 2.6900 1
element Truss 5 1 3 2.9670 1
element Truss 6 2 3 2.0120 1
element Truss 7 10 6 2.6900 1
element Truss 8 9 6 1.6470 1
element Truss 9 7 6 0.6740 1
element Truss 10 1 6 2.9670 1
element Truss 11 2 6 2.0120 1
element Truss 12 3 6 0.0110 1
element Truss 13 9 4 0.6740 1
element Truss 14 8 4 2.6900 1
element Truss 15 7 4 1.6470 1
element Truss 16 1 4 2.0120 1
element Truss 17 2 4 2.9670 1
element Truss 18 3 4 0.0110 1
element Truss 19 10 5 1.6470 1
element Truss 20 9 5 2.6900 1
element Truss 21 8 5 0.6740 1
element Truss 22 1 5 2.0120 1
element Truss 23 2 5 2.9670 1
element Truss 24 6 5 0.0110 1
element Truss 25 4 5 0.0110 1
timeSeries Linear 1
pattern Plain 1 1 {
load 1 1 10 -5
load 2 0 10 -5
load 3 .5 0 0
load 6 .5 0 0
load 1 0 20 -5
load 2 0 -20 -5
}
system BandGeneral
numberer RCM
constraints Plain
integrator LoadControl 1.0
algorithm Linear
recorder Node -file example.out -time -node 3 -dof 1 2 disp
analysis Static
logFile "log.txt"
analyze 1
print node
[/code]
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