Modifying just bending stiffness without chaning axial stiffness?


I am a master student in structural engineering.

Is there a way to modify just bending stiffness in beams (or in slabs) by some random number i want without modifying axial or shear stiffness?

I am aware of functions FACS, however this functions modify all of the stiffnesses. Also, im familiar with functions STEA,QUEA, QUEX,QUEM,but all of those are modifying axial stiffness. Also QEMX and QEMY change modulus of elasticity in different direction which could be thing i want but that way it affects also on axial stiffness of quad element, and i dont want that (If im right?).

Basically i want to “simulate” cracked state of concrete element (in building) in ULS combination for seismic calculation. According to Eurocode8, i can modify bending and shear stiffness to 50% of value of fully elastic stiffness and still use linear theory. All of that without modifying axial stiffness. I would appreciate any help.

Kind regards

It is not possible to modify only the bending stiffness with GRP2 commands.
For cross sections you can set Iy Iz,… in detail, see command SVAL manual AQUA.
Hope this helps.

Best regards,
Your SOFiSTiK Support Team