how to get the maxpricipal at unique nodal through abaqus python?

[Dimitri666]

could you please tell how to get the maxpricipal at unique nodal through abaqus python? I tried but the result is not good because the value averaging exists.

[Panavia-Tornado]

You can get nodes from an ODB assembly by label or coordinate (if you need global coordinates, you should translate them from the instance coordinate system to the assembly):

my_node = odb.rootAssembly.instances[instance_name].nodes[0]

Then, you retrieve the stress tensor field S from a specific step and frame:

stress_field = odb.steps['Step-1'].frames[-1].fieldOutputs['S']

Then, you get the subset for your specific node region:

node_subset = stress_field.getSubset(region=my_node)

Finally, Abaqus automatically calculates invariants for the stress tensor, so you can access the maximum principal stress directly via the .maxPrincipal attribute of the field values (or calculate from stress components via field_value.data ):

max_principal_values = [field_value.maxPrincipal for field_value in node_subset.values]