Error with torsion

[philiplukek]

hii

i am trying to validate the results of a 2D bay 4 column bay frame with that of 3d 4 column frame. The 2D model and the analysis results are allright but when i try to model the 3D and analyse, the following warning is coming up for each of my element

ForceBeamColumn3d::ForceBeamColumn3d -- no torsion detected in sections, continuing with element torsional stiffness GJ/L

I had defined the torsion using aggregator command but those do not seem to have an effect on the model. i tried the model with and without the aggregator but the result is the same. so i guess my mistake lies in the aggregator command but i cant seem to find any error. following is my command

# assign torsional Stiffness for 3D Model
uniaxialMaterial Elastic $SecTagTorsion $Ubig
section Aggregator $ColSecTagTorsion41 $SecTagTorsion T -section $ColSecTag11
section Aggregator $BeamXSecTagTorsion51 $SecTagTorsion T -section $BeamXSecTag21
section Aggregator $BeamZSecTagTorsion61 $SecTagTorsion T -section $BeamZSecTag31

could someone please help me with this. i am very much new to opensees. Thank You.