I’m writing a code in python that extracts the contact stress (CPRESS) in Abaqus 2019 of all the nodes on a given surface. I managed to write the code so that the Node-Label as well as the coordinates of the nodes from the surface get extracted and are written to a csv file. However, I’m not having any success in accessing the CPRESS-Value for the nodes that I’m interested in.

I read in the user’s manual about where to find the values of CPRESS, but I don’t see the reason, on why the code isn’t extracting any values for the given nodes. There is my code:

import csv
from odbAccess import *

odb_Pfad = '123.odb' #not important
odb = openOdb(odb_Pfad)

instance_name = 'PRUEFKOERPER_4-1'
instance = odb.rootAssembly.instances[instance_name]

start_node_id = 0
end_node_id = 5000

partlabel = []
partxcord = []
partycord = []
partzcord = []

for node in instance.nodes:
    if start_node_id <= node.label <= end_node_id:
        partlabel.append(node.label)
        partxcord.append(node.coordinates[0])
        partycord.append(node.coordinates[1])
        partzcord.append(node.coordinates[2])

step_name = 'Belastung'
step = odb.steps[step_name]
last_frame = step.frames[-1]  #Last frame
cpress_dict = {value.nodeLabel: value.magnitude for value in last_frame.fieldOutputs['CPRESS'].values}

#write a csv file with the node ladel and the coordinates of the corresponding node, as  well as cpress-Value
csv_datei = '123.csv' #not important
with open(csv_datei, 'wb') as file:
    writer = csv.writer(file)
    writer.writerow(['Knoten ID', 'x', 'y', 'z', 'CPRESS'])
    for i in range(len(partlabel)):
        cpress_value = cpress_dict.get(partlabel[i], 'N/A')
        writer.writerow([partlabel[i], partxcord[i], partycord[i], partzcord[i],     cpress_value])

odb.close()