STRESS array is empty in python scripting Abaqus

Question

I wanted to extract stress on top surface of my model on each node but it can't be done normally. when I use this script:

odb = visualization.openOdb('My.odb')
frame=odb.steps['AStep'].frames[-1]

dispNode = odb.rootAssembly.nodeSets['UPPER']

STRESS= frame.fieldOutputs['S'].getSubset(region=dispNode).values
COORD= frame.fieldOutputs['COORD'].getSubset(region=dispNode).values

print(STRESS)
print(COORD[1].data)

STRESS returns an empty array.

How can I edit my script to have stress and its corresponding coordinates??

Answer 1

Your Code can't work, if you only calculated your stress values on the integration points. There are simply no values at the nodes, so if you request values at nodes you will get an empty array.

This is how it should work:

• Extrapolate your integration point results to the nodes
• Average your ElementNodal values. This is how that works: https://stackoverflow.com/a/43175485/4045774
• Extract your node coordinates (deformed or undeformed)
• get the node labels from your point set
• With the node labels from your point set find the corresponding unique nodal values https://docs.scipy.org/doc/numpy/reference/generated/numpy.in1d.html

If you need a small example code, feel free to ask.