3D truss model

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Ashok
Posts: 50
Joined: Tue Feb 19, 2019 8:59 pm
Location: IITM

3D truss model

Post by Ashok » Tue Jan 12, 2021 10:32 pm

Code: Select all

# Remove existing model
wipe


model BasicBuilder -ndm 3 -ndf 6


node 1 0 0 0 
node 2 0 2400 0
node 3 1200 2400 0
node 4 1200 0 0
    

fix 1 1 1 1 0 0 0
fix 4 1 1 1 0 0 0
fix 2 0 0 1 0 0 0
fix 3 0 0 1 0 0 0    


uniaxialMaterial Elastic 1 3000


# Create truss elements - command: element truss trussID node1 node2 A matID
element truss 1 1 2 5.0 1
element truss 2 2 3 5.0 1
element truss 3 3 4 5.0 1
element truss 4 1 3 5.0 1

# Define loads
# ------------
#

# create a Linear TimeSeries with a tag of 1
timeSeries Linear 1
    
# Create a Plain load pattern associated with the TimeSeries,
# command: pattern Plain $patternTag $timeSeriesTag { load commands }

pattern Plain 1 1 {
    
   
   load 2 100 0 0 0 0 0
}
# Create the system of equation
system BandGeneral
    
# Create the DOF numberer, the reverse Cuthill-McKee algorithm
numberer RCM
    
# Create the constraint handler, a Plain handler is used as homo constraints
constraints Transformation

# Create the integration scheme, the LoadControl scheme using steps of 1.0
integrator LoadControl 0.1

# Create the solution algorithm, a Linear algorithm is created
algorithm Linear

# create the analysis object 
analysis Static 

recorder display panel 30 30 400 400
prp 2400 1 2400
vup 0 1 0
vpn 0 0 1
viewWindow -2400 2400 -2400 2400
display 1 4 5

analyze 1
puts [nodeDisp 3]
puts [nodeDisp 2]
Hi,
I am getting error for this. Can you kindly find out the mistake I made ?
It's basically a planar truss but defined in 3D. I suppose it should work, but it is giving Lapack error

Thank you.

Ashok
Posts: 50
Joined: Tue Feb 19, 2019 8:59 pm
Location: IITM

Re: 3D truss model

Post by Ashok » Wed Jan 13, 2021 1:49 am

Ok ! I got the point
the support condition should be

fix 1 1 1 1 1 1 1
fix 2 0 0 1 1 1 1
fix 3 0 0 1 1 1 1
fix 4 1 1 1 1 1 1
All the rotational dof's should be restrained + out of plane restraints also should be added.

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