Wrapper's Delight

Original Post - 19 May 2024 - Michael H. Scott

Visit Structural Analysis Is Simple on Substack.

What is the output produced by this analysis?

Sure, you can copy and paste the script to get the answer. But that’s no fun.

Think about the model and analysis. Can you explain what’s going on before getting the answer?

import openseespy.opensees as ops

ops.wipe()
ops.model('basic','-ndm',1,'-ndf',1)

N = 365

ops.uniaxialMaterial('Elastic',0,1.0)
for i in range(N):
    ops.uniaxialMaterial('Multiplier',i+1,i,1.01)

ops.node(1,0); ops.fix(1,1)
ops.node(2,0)

ops.element('zeroLength',1,1,2,'-mat',N,'-dir',1)

ops.timeSeries('Constant',1)
ops.pattern('Plain',1,1)
ops.sp(2,1,1.0)

ops.constraints('Transformation')
ops.system('UmfPack')
ops.analysis('Static','-noWarnings')

ops.analyze(1)
ops.reactions()

print(-ops.nodeReaction(1,1))

Read this post to find out more about the Multiplier material wrapper.