axial force in beam

mohsenkh · Post by **mohsenkh** » Fri Oct 08, 2010 4:04 am

Dear Fmk

I modeled RC resistant moment frame. Beams and columns were modeled by forceBeamColumn. In the beams the axial force is considerable. Is this resonable?

Best regards;
Mohsen.

vesna · Post by **vesna** » Mon Oct 11, 2010 11:10 am

If you used equalDOF command to constrain horizontal displacements at one floor level, that might be the reason for getting unreasonably high axial forces. These forces are not realistic. Force Beam-Column messes up the axial force if axial deformation is 0.

If axial forces in the beams are important avoid equalDOF constraints. If axial force is not important, use displacement beam-column element to model it and with the applied constraint you should get zero axial forces.

mohsenkh · Post by **mohsenkh** » Wed Nov 03, 2010 3:08 am

Dear Fmk or Siliva

I modeled RC resistant moment frame subjected earthquake load. I used ForceBeam-Column element in my model. Meanwhile I used equalDOF command to constrain horizontal displacements at each floor level. There is axial force in the beams. Is this right?