error of different field size when adding effective stress plus pore pressure field

YL 2020-09-02

I need your help again. In SOILS, the stress is effective stress. I like to see the total stress contour.

Basically I just add two fields of S3 plus POR. Since S3 data is in the integration point by default while POR is in nodal position. So I changed Element Ouput in INP to be like this

*Element Output,POSITION=AVERAGED AT NODES, directions=YES
E, EE, FV, HP, IE, MISES, P, PE, PEEQ, PEEQMAX, PEMAG, S, SF, TEMP, THE

In CAE, there is an error saying the output region size is different and suggest me to use fieldouputrequest.getsubset(). So I have to write a script like below by using getsubset()

S_thisframe = frame.fieldOutputs['S'].getSubset(region=inst,elementType='C3D8P',position=NODAL)
POR_thisframe = frame.fieldOutputs['POR'].getSubset(region=inst,position=NODAL)
TotalS3Field = S_thisframe.getScalarField(componentLabel="S33")+POR_thisframe

I still get the same error like attached.

So I output the size of above stress and pore pressure field outputs, the sizes are indeed different. That is why I cannot add them together. I don't know whey the sizes are different. The results should be on node position now after using POSITION=AVERAGED AT NODES in inp file. Could you please help me with this issue? How to show total S33 contour?

>>> print len(S_thisframe.values)
38070
>>> print len(POR_thisframe.values)
35532

Thank you so much for your help. I appreciate it.