Is it possible to change a cross-section property (torsional constant) of a CS created in MODELER, without using "Beam, CS values" element type?

Question

Hello community, I am trying to edit the cross-sectional properties of the elements of a grillage model, in order to simulate the torsional stiffness of a multicellular deck. I have created the web sections using MODELER and assigned them appropriately. Now I look to artificially change the torsional constant and vertical shear area without losing the CS(Begin) / CS(End) definition in the cross-section assignments (and the reference points I need to perform stress checks). Using the "Beam, CS values" in the cross-section assignment to edit the torsional constant dismisses the MODELER cross-section assignment and the reference points are thus lost. 
 Is it at all possible to edit a cross-section property without losing the rest of the MODELER definitions and the remaining calculated mechanical properties? 
 Thanks everyone in advance for any input you can give me.

Diether · Accepted Answer

Hi Pedro, 
 For this purpose there are two possibilities; one is changing the section properties on the cross-section level and the other is changing the stiffness on the element level: 
 1.) Menu Properties/Cross-sections/Parts : 
 - Edit a cross-section part in the bottom table 
 - Apply the reduction factors for Mx, Qy, Qz 
 2.) Schedule Action Structure change commands / ElemK : 
 - Factors for Ax, Ay, Az and Ix, Iy, Iz can be applied (Note: Action not applicable for composite elements) 
 (Press F1 within both windows for more details). 
 Regards, 
 Diether